U.S. patent application number 13/554366 was filed with the patent office on 2012-11-08 for purification of and air methods of making and using the same.
This patent application is currently assigned to LIFEAIRE SYSTEMS, LLC. Invention is credited to Kathryn C. Worrilow.
Application Number | 20120283508 13/554366 |
Document ID | / |
Family ID | 47090681 |
Filed Date | 2012-11-08 |
United States Patent
Application |
20120283508 |
Kind Code |
A1 |
Worrilow; Kathryn C. |
November 8, 2012 |
PURIFICATION OF AND AIR METHODS OF MAKING AND USING THE SAME
Abstract
Purified air is provided, having a TVOC content of from less
than 5 ppb to about 500 ppb, a Biologicals content of from less
than 1 CFU/M.sup.3 to 150 CFU/M.sup.3 and a Particulate content of
from about 1,000 0.3 .mu.m particles per ft.sup.3 to about 50,000
0.3 .mu.m particles per ft.sup.3, or from about 600 0.5 .mu.m
particles per ft.sup.3 to about 500,000 0.5 .mu.m particles per
ft.sup.3.
Inventors: |
Worrilow; Kathryn C.;
(Fogelsville, PA) |
Assignee: |
LIFEAIRE SYSTEMS, LLC
Allentown
PA
|
Family ID: |
47090681 |
Appl. No.: |
13/554366 |
Filed: |
July 20, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13244973 |
Sep 26, 2011 |
8252100 |
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13554366 |
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12732246 |
Mar 26, 2010 |
8252099 |
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13244973 |
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Current U.S.
Class: |
600/33 ; 252/372;
423/245.1 |
Current CPC
Class: |
B01D 2257/708 20130101;
F24F 2110/66 20180101; B01D 53/04 20130101; B01D 53/02 20130101;
Y02B 30/70 20130101; F24F 2110/20 20180101; A61L 2209/14 20130101;
A61L 2209/16 20130101; B01D 2255/2073 20130101; B01D 2257/91
20130101; B01D 2259/4533 20130101; F24F 5/0089 20130101; B01J
20/28052 20130101; F24F 11/0008 20130101; A61B 17/43 20130101; F24F
2110/10 20180101; B01D 2259/804 20130101; B01J 20/20 20130101; F24F
3/16 20130101; B01D 2253/112 20130101; B01D 2259/4508 20130101;
B01J 20/0222 20130101; F24F 11/30 20180101; A61L 9/20 20130101;
B01D 46/0028 20130101; B01D 46/521 20130101; B01J 20/04 20130101;
B01J 2220/42 20130101; B01D 46/0036 20130101; B01D 53/007 20130101;
F24F 2003/1667 20130101; B01D 2267/40 20130101; F24F 2003/1625
20130101; B01D 2253/102 20130101 |
Class at
Publication: |
600/33 ; 252/372;
423/245.1 |
International
Class: |
A61L 9/20 20060101
A61L009/20; A61B 17/425 20060101 A61B017/425; C09K 3/00 20060101
C09K003/00 |
Claims
1. Purified air, characterized by: a. a TVOC content of from less
than 5 ppb to about 500 ppb; b. a Biologicals content of from less
than 1 CFU/M.sup.3 to 150 CFU/M.sup.3; and c. a Particulate content
of from about 1,000 0.3 .mu.m particles per ft.sup.3 to about
50,000 0.3 .mu.m particles per ft.sup.3, or from about 600 0.5
.mu.m particles per ft.sup.3 to about 500,000 0.5 .mu.m particles
per ft.sup.3.
2. The purified air of claim 1, wherein the TVOC content is less
than 5 ppb, the Biologicals content is less than 1 CFU/M.sup.3 and
the Particulate content is from about 1,000 0.3 .mu.m particles per
ft.sup.3 to about 10,500 0.3 .mu.m particles per ft.sup.3, or from
about 600 0.5 .mu.m particles per ft.sup.3 to about 1,000 0.5 .mu.m
particles per ft.sup.3.
3. A method of achieving an IVF clinical pregnancy rate of at least
50%, the method comprising performing multiple IVF cycles in an IVF
laboratory having air characterized by: a. a TVOC content of from
less than 5 ppb to about 500 ppb; b. a Biologicals content of from
less than 1 CFU/M.sup.3 to 150 CFU/M.sup.3; and c. a Particulate
content of from about 1,000 0.3 .mu.m particles per ft.sup.3 of air
to about 30,000 0.3 .mu.m particles per ft.sup.3 of air, or from
about 600 0.5 .mu.m particles per ft.sup.3 of air to about 10,000
0.5 .mu.m particles per ft.sup.3 of air, thereby achieving an IVF
clinical pregnancy rate of at least 50%.
4. The method of claim 3, wherein the IVF clinical pregnancy rate
is from 50% to 70%.
5. The method of claim 3, wherein the IVF clinical pregnancy rate
is from 50% to 65%.
6. The method of claim 3, wherein the IVF clinical pregnancy rate
is from 55% to 70%.
7. The method of claim 3, wherein the IVF clinical pregnancy rate
is from 55% to 65%.
8. A method of achieving an IVF clinical pregnancy rate of at least
50%, the method comprising performing multiple IVF cycles in an IVF
laboratory having purified air characterized by: a. a TVOC content
of less than 5 ppb; b. a Biologicals content of less than 1
CFU/M.sup.3; and c. a Particulate content from about 1,000 0.3
.mu.m particles per ft.sup.3 to about 10,500 0.3 .mu.m particles
per ft.sup.3, or from about 600 0.5 .mu.m particles per ft.sup.3 to
about 1,000 0.5 .mu.m particles per ft.sup.3, thereby achieving an
IVF clinical pregnancy rate of at least 50%.
9. The method of claim 8, wherein the IVF clinical pregnancy rate
is from 50% to 70%.
10. The method of claim 8, wherein the IVF clinical pregnancy rate
is from 50% to 65%.
11. The method of claim 8, wherein the IVF clinical pregnancy rate
is from 55% to 70%.
12. The method of claim 8, wherein the IVF clinical pregnancy rate
is from 55% to 65%.
13. A method of purifying air, comprising the steps of: a.
providing an air flow path through a housing for the flow of air in
a downstream direction; b. filtering the air through oxidizing and
adsorbing VOC pre-filtration within the housing; c. filtering the
air through UV filtration within the housing, downstream from the
oxidizing and adsorbing VOC pre-filtration; and d. filtering the
air through final particulate filtration within the housing,
downstream from the UV filtration.
14. The method of claim 13, further comprising the step of
filtering the air through particulate pre-filtration within the
housing, upstream from the VOC pre-filtration.
15. The method of claim 13, wherein the VOC pre-filtration
comprises bonded carbon.
16. The method of claim 13, further comprising the step of
filtering the air through oxidizing and adsorbing VOC
post-filtration within the housing, downstream from the UV
filtration and upstream from the final particulate filtration.
17. The method of claim 13, wherein the VOC pre-filtration
comprises one or more filters containing blended carbon and
KMnO.sub.4.
18. The method of claim 13, further comprising the steps of
filtering the air through particulate pre-filtration within the
housing, upstream from the VOC pre-filtration and filtering the air
through oxidizing and adsorbing VOC post-filtration within the
housing, downstream from the UV filtration and upstream from the
final particulate filtration.
19. The method of claim 18, wherein the VOC pre-filtration and VOC
post-filtration comprise one or more filters containing blended
carbon and KMnO.sub.4.
Description
BACKGROUND OF THE INVENTION
[0001] This application is a continuation-in-part of U.S. patent
application Ser. No. 13/244,973, filed on Sep. 26, 2011, which is a
continuation of U.S. patent application Ser. No. 12/732,246, filed
on Mar. 26, 2010. International Application No. PCT/US2011/029567,
filed on Mar. 23, 2011, claims priority to U.S. patent application
Ser. No. 12/732,246.
FIELD OF INVENTION
[0002] This invention relates to devices and methods for the
filtration and purification of air. More particularly, this
invention relates to air purifiers capable of providing a level of
air quality suitable for environments that are highly sensitive to
airborne contaminants, e.g., in vitro fertilization laboratories or
other medical environments. Further, the invention may be adapted
for use in any substantially enclosed environment, including, but
not limited to, homes, residential buildings, commercial buildings,
hotels, cars, buses, trains, airplanes, cruise ships, educational
facilities, offices, and government buildings. The invention may
also have applications in, e.g., national security, defense, or
airline industries.
DESCRIPTION OF RELATED ART
[0003] In vitro fertilization ("IVF") is a procedure whereby egg
cells are fertilized by sperm in a laboratory environment, instead
of in the womb. If an egg cell is successfully fertilized, it may
be transferred into the uterus of a patient wishing to become
pregnant.
[0004] IVF may be an effective option for patients suffering from
infertility, especially where other methods of assisted
reproduction have failed. However, IVF is very expensive and is not
typically covered by medical insurance. In 2009, the cost of a
single cycle of IVF was approximately $10,000 to $15,000 in the
United States. It is financially prohibitive for most people to
undergo multiple rounds of IVF. It is therefore imperative that
conditions for successful pre-implantation embryogenesis are
optimized, in order to maximize the likelihood of success.
[0005] One extremely important factor contributing to the
likelihood of successful pre-implantation embryogenesis is the air
quality of the IVF laboratory. Gametes and embryos grown in vitro
are highly sensitive to environmental influences. Human embryos
have no means of protection or filtration against environmental
toxins and pathogens. They are completely at the mercy of their
environment. The incubators which house the human embryos often
consist of a significant percentage of room air. Although airborne
contaminants can adversely affect embryogenesis, surprisingly
little emphasis has been placed on optimizing laboratory air
quality during the last three decades in which IVF has been
available as a treatment for infertility.
[0006] Existing filtration devices have been found insufficient to
optimize air quality to truly acceptable levels for IVF. For
example, it has been found that laboratory air that had been
filtered with only high efficiency particulate air ("HEPA") filters
was actually of lesser quality than outside air. Additionally, some
filters produce by-products or other contaminants that actually
detract from the quality of the air in an IVF laboratory. For
example, carbon filters can create carbon dusting that is harmful
to the IVF process. This is not to say, however, that carbon
filters or HEPA filters should not be used to treat air supplied to
an IVF laboratory. On the contrary, it is preferred that carbon
filters, HEPA filters, or their respective equivalents, are
included among filtration media used to treat air supplied to an
IVF laboratory. Attaining optimal air quality in an IVF laboratory
or other substantially enclosed space requires proper selection,
combination and sequencing of various filtration media.
BRIEF SUMMARY OF THE INVENTION
[0007] Accordingly, air characterized by very high purity and
methods of making and using such air, are provided.
[0008] In one aspect of the present invention, air is provided,
characterized by a TVOC content of from less than 5 ppb to about
500 ppb, a Biologicals content of from less than 1 CFU/M.sup.3 to
150 CFU/M.sup.3 and a Particulate content of from about 1,000 0.3
.mu.m particles per ft.sup.3 to about 50,000 0.3 .mu.m particles
per ft.sup.3, or from about 600 0.5 .mu.m particles per ft.sup.3 to
about 500,000 0.5 .mu.m particles per ft.sup.3.
[0009] Another aspect of the present invention is a method of
achieving an IVF clinical pregnancy rate of at least 50%. The
method includes performing multiple IVF cycles in an IVF laboratory
having air characterized by a TVOC content of from less than 5 ppb
to about 500 ppb, a Biologicals content of from less than 1
CFU/M.sup.3 to 150 CFU/M.sup.3 and a Particulate content of from
about 1,000 0.3 .mu.m particles per ft.sup.3 to about 50,000 0.3
.mu.m particles per ft.sup.3, or from about 600 0.5 .mu.m particles
per ft.sup.3 to about 500,000 0.5 .mu.m particles per ft.sup.3.
[0010] Another aspect of the present invention is a method of
purifying air, including providing an air flow path through a
housing for the flow of air in a downstream direction, filtering
the air through oxidizing and adsorbing VOC pre-filtration within
the housing, filtering the air through
[0011] UV filtration within the housing, downstream from the
oxidizing and adsorbing VOC pre-filtration and filtering the air
through final particulate filtration within the housing, downstream
from the UV filtration.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS
[0012] The invention will be described in conjunction with the
following drawings in which like reference numerals designate like
elements and wherein:
[0013] FIG. 1 is a top view of an air purifier according to the
present invention.
[0014] FIG. 2 is a side view of an air purifier according to the
present invention.
[0015] FIG. 3 is an internal view of the air purifier along the
plane defined by section line A--A of FIG. 1.
[0016] FIG. 4 is an internal view of the air purifier along the
plane defined by section line B--B of FIG. 2.
DETAILED DESCRIPTION OF THE INVENTION
[0017] Referring now in detail to the various figures of the
drawings wherein like reference numerals refer to like parts, there
are shown in FIGS. 1 and 2 top and side views, respectively, of an
air purifier 2 according to the present invention. As illustrated,
the air purifier 2 includes a substantially rectangular cuboid
housing 4 having an inlet 6 for receiving air and an outlet 8 for
exhausting air. The term "air" as used herein broadly refers to a
gas or gaseous mixture that may be safely breathed by mammals
and/or that can serve as a source gas or gaseous mixture towards an
IVF laboratory. The housing 4 provides an air flow path for the
flow of air in a downstream direction, i.e., from the inlet 6
towards the outlet 8. The term "housing" as used herein refers to
any conduit, chamber and/or enclosure, or a plurality of conduits,
chambers and/or enclosures coupled to one another, providing an air
flow path within. Thus, the "housing" could include, e.g., ductwork
of an existing heating, ventilating and air conditioning ("HVAC")
system or air handling unit ("AHU").
[0018] Although the housing 4 is preferably substantially
rectangular cuboid, as shown in FIGS. 1 and 2, it need not be
limited to any particular shape. Moreover, it may include inner
curves, bends and/or other contours, whereby the air flow path
would follow such curves, bends and/or other contours. Preferably,
however, the air flow path is substantially straight, as it is in
the embodiment of the housing 4 shown in FIGS. 1 and 2.
[0019] The air purifier 2 is preferably adapted to be installed
into an existing HVAC system or AHU. In an alternative embodiment,
an air purifier according to the present invention may function as
a stand-alone unit, i.e., one that is not part of an HVAC system or
AHU. An exemplary housing 4 may be a substantially rectangular
cuboid having dimensions of approximately 11 ft. long by 4 ft. wide
by 2 ft. high. Such dimensions would diffuse or spread out the air
through the air purifier 2 so as to provide sufficient resonance
time for the air through each of the filtration media discussed
infra. A skilled artisan understands, however, that the foregoing
exemplary shape and size parameters are merely illustrative, and
may be changed, even substantially, depending on the circumstances
or application. For example, in some applications, the air purifier
2 may be about 6 ft. long. Referring now to FIG. 3, there is shown
an internal view of the air purifier 2 along the plane defined by
section line A--A of FIG. 1. In FIG. 4, there is shown an internal
view of the air purifier 2 along the plane defined by section line
B--B of FIG. 2.
[0020] To obtain optimal air quality, e.g., suitable for an IVF
laboratory, the air that is treated by the air purifier 2 should be
pre-conditioned and stable, i.e., moderate both in terms of
temperature and humidity. Ideally, the air that is treated by the
air purifier 2 should have a temperature of between about
68.degree. F. and 75.degree. F., and a humidity of between about
45% and 55%. Additionally, the air flow rate through the air
purifier 2 should preferably be about 250 ft./min. and below 2000
CFM. This preferred flow rate is intended to provide sufficient
resonance time for the air through each of the filtration media
discussed infra. The term "filtration" as used herein, broadly
covers one or more devices that treat air, such as by trapping,
removing, deactivating and/or destroying contaminants
therefrom.
[0021] In order to provide an adequate air flow rate through the
air purifier 2, it may be helpful (although not always necessary)
to include a booster fan 10 downstream from the inlet 6. The
booster fan 10 may be coupled to a control system (not shown) that
measures the air flow rate and triggers the booster fan 10 as
needed, to maintain the desired air flow rate. In an alternative
embodiment (not shown), a booster fan may not be included, and
adequate air flow rate may be provided and maintained by other
means, e.g., a blower in an HVAC system or AHU into which the air
purifier 2 is installed.
[0022] Downstream from the inlet 6 is particulate pre-filtration 12
for the trapping of airborne particulate. The particulate
pre-filtration 12 is preferably about 2 inches thick in one
embodiment, and includes left and right pleated particulate
pre-filters 14,16. The particulate pre-filters 14,16 trap gross
particulate (e.g., dust and bugs) from the outside air before that
air reaches the other filtration media in the air purifier 2
discussed infra. Suitable filters for the particulate
pre-filtration 12 are those having a Minimum Efficiency Reporting
Value ("MERV") of 5 to 13 with an Average ASHRAE Dust Spot
Efficiency (Standard 52.1) of 20% to 80%. Particularly preferred
filters for the particulate pre-filtration 12 are pleated filters
having a MERV of 7 to 8, with an Average ASHRAE Dust Spot
Efficiency (Standard 52.1) of 30% to 45%.
[0023] Proper particulate pre-filter selection should be guided by
the need to trap gross-particulate without unduly affecting the air
flow rate through the air purifier 2. The particular type of
particulate pre-filter(s) selected for particulate pre-filtration
depends on various factors, including outside air quality. It is
preferred that the particulate pre-filtration 12 is located
immediately upstream from the additional filtration media discussed
infra, as shown in FIGS. 3 and 4. Alternatively (or in addition),
however, particulate pre-filtration may be located further
upstream, e.g., in upstream ductwork of an HVAC system or AHU into
which the air purifier 2 is installed.
[0024] Downstream from the particulate pre-filtration 12 is
volatile organic compound ("VOC") pre-filtration 18. Once air
passes through the particulate pre-filtration 12, the air is
effectively free of gross particulate that would otherwise diminish
the efficacy and useful life of the VOC pre-filtration 18. VOC
pre-filtration ideally includes adsorption media, such as carbon,
as well as oxidation media, such as potassium permanganate
("KMnO.sub.4") or a photocatalytic oxidizer. A particularly
preferred type of carbon is virgin coconut shell. In a preferred
embodiment, the VOC pre-filtration 18 is a carbon and KMnO.sub.4
blend, e.g., in a 50/50 proportion. In some embodiments, the blend
may include additional elements, such as natural zeolite. The
proportion of the blend may vary depending on the types and levels
of VOCs present in the source air. Ideally, the source air would be
tested for VOCs, and, based on test results, a custom blend would
be prepared to maximize VOC removal in a given environment. In an
alternative embodiment of the VOC pre-filtration (not shown),
separate (i.e., non-blended) carbon and KMnO.sub.4 filters are
used.
[0025] The embodiment of the VOC pre-filtration 18 shown in FIGS. 3
and 4 includes a total of twenty stacked filter trays 20,22,
whereby ten such trays 20 are on the left side of the housing 4 and
ten such trays 22 are directly adjacent, to the right. The length
of the trays, i.e., the longitudinal distance over which the air
flows, is preferably about 17 inches in one embodiment, though it
may be shorter or longer. Each tray 20,22 includes two blended
carbon and KMnO.sub.4 filters 24, arranged in a V-bank along a
vertical plane (e.g., the plane of FIG. 3). The V-bank arrangement
increases the surface area of the filters 24 over which air must
travel, thereby enhancing the effectiveness of the VOC
pre-filtration 18. Once air passes through the VOC pre-filtration
18, the VOC load of the air is effectively reduced.
[0026] Downstream from the VOC pre-filtration 18 is particulate
post-filtration 26 for the trapping of airborne particulate, e.g.,
particulate generated by the VOC pre-filtration 18 (such as carbon
dusting). The particulate post-filtration 26 includes left and
right pleated particulate post-filters 28,30. The filters used in
the particulate post-filtration 26 may be identical or similar to
those used in the particulate pre-filtration 12, discussed supra.
While particulate post filtration 26 downstream from the VOC
pre-filtration 18 is preferred, it may not be necessary in all
applications. For example, if the VOC pre-filtration is of a type
that does not generate air-borne particulate, such as bonded
carbon, particulate post-filtration may be optional.
[0027] Downstream from the particulate post-filtration 26 is
ultraviolet ("UV") filtration 32 which destroys airborne biological
contaminants and, in some embodiments, degrades chemical
contaminants. Whether or not particulate post-filtration 26 is
used, the air reaching the UV filtration 32 should be effectively
free of gross particulate and contain dramatically reduced levels
of VOCs so as not to diminish the efficacy of the UV filtration
32.
[0028] The UV filtration may include one or more UV sources,
although a plurality of UV sources is preferred. It is further
preferred that these UV sources are UVC sources, capable of
generating UV radiation at a wavelength varying from 220 nm to 288
nm. Most preferably, the UVC sources are capable of generating UV
radiation at a wavelength of 260 nm, however commercially available
UVC sources capable of generating UV radiation at a wavelength of
254 nm are adequate. In an alternative embodiment described in U.S.
Pat. No. 5,833,740 (Brais), which is incorporated herein by
reference in its entirety, the UV filtration includes at least one
vacuum UV source, capable of generating UV radiation at a
wavelength varying from 170 nm to 220 nm (preferably 185 nm) and at
least one UVC source, capable of generating UV radiation at a
wavelength varying from 220 nm to 288 nm (preferably 260 nm). In
that embodiment, the UVC source is preferably downstream from the
vacuum UV source. When operating, the vacuum UV source breaks
oxygen molecules into mono-atomic oxygen which then reacts with
chemical contaminants present in the air and then degrades them by
successive oxidation to odorless and inoffensive byproducts. The
UVC source kills biological contaminants present in the air by
irradiation and degrades residual ozone produced by the vacuum UV
source into molecular oxygen.
[0029] Particularly preferred UV filtration 32 shown in FIGS. 3 and
4 is the "UV Bio-wall" made by Sanuvox. Alternatively, the "Bio
30GX," which is also made by Sanuvox, is a preferred type of UV
filtration. The UV filtration 32 includes a pair of fixtures 34, 36
each of which has five UV lamps 38 (not all five of which are
visible in the Figures). The UV lamps 38 are preferably about 60
inches long and extend longitudinally through the housing 4 so as
to maximize exposure time of the air to UV radiation. In one
embodiment, the UV lamps are UVC sources, providing UV radiation
within the UVC wavelength parameters discussed supra. In an
alternative embodiment, described in U.S. Pat. No. 5,833,740
(Brais), each lamp 38 is dual-zoned, having an upstream vacuum UV
source and a downstream UVC source. In that alternative embodiment,
the upstream vacuum UV source may, e.g., be a high intensity
mercury vapor lamp capable of generating UV radiation having a
wavelength in a range of about 170 nm to about 220 nm, and the
downstream UVC source may, e.g., be a low intensity mercury vapor
lamp capable of generating radiation having a wavelength in a range
of about 220 nm to about 288 nm. The interior 44 of the housing 4
encasing the UV filtration 32 is highly reflective, with a
preferable coefficient of reflection of at least 60%, so as to
enhance the effectiveness of the lamps 38.
[0030] The kill rate of biological contaminants is a function of
the intensity of UVC radiation produced by the UV filtration 32 and
reflected by the interior 44 of the housing 4, as well as the
exposure time of such contaminants to the UVC radiation. Thus, the
higher the intensity of the UVC radiation and the longer the
exposure time of such contaminants to the UVC radiation, the
greater is the level of sterilization achieved. Depending on
factors such as the desired level of sterilization, the amount of
space available to house UV filtration, and costs of operating and
maintaining UV filtration, the desired total UVC output of the UV
filtration 32 may vary. In one actual embodiment, it was found that
a total UVC output ranging from about 33,464 .mu.J/cm.sup.2 to
about 90,165 .mu.J/cm.sup.2, with an average total UVC output of
about 43,771 .mu.J/cm.sup.2, provided a desired level of
sterilization, given practical constraints of cost and space. Such
total UVC output killed 100% of numerous biological contaminants
including, but not limited to smallpox, flu, tuberculosis, anthrax
and H1N1 virus.
[0031] The UV filtration 32 contained within the housing 4 is
likely not visible to a user of the air purifier 2 when in use,
because direct UV exposure is harmful to humans. Thus, a user
cannot ascertain visually (i.e., by simply looking at the air
purifier 2 itself) whether the lamps 38 are operating at a given
time. It cannot be assumed that the air purifier 2 is effectively
destroying air-borne biological and chemical contaminants, without
knowing for sure that the UV filtration is operating properly.
Accordingly, it is preferred that the present invention include
sensors and a monitor (not shown) to detect and indicate,
respectively, how much time each UV lamp 38 has been in use and
whether each lamp 38 is operating at a given time. The monitor may
include, e.g., a scrolling digital clock, which indicates the
length of time each lamp 38 has been operating. These sensors and
monitor would indicate to a user when it is time to replace any of
the lamps 38.
[0032] As a general matter, moisture within the housing 4 can
foster the growth of biological contaminants. Accordingly, it is
preferable to include a UVC source in the vicinity of areas in
which moisture is generated or gathers. For example, upstream from
the particulate pre-filtration 12 may be one or more cooling coils
(not shown) that help to ensure that the air which is treated by
the air purifier 2 is moderate in terms of temperature. Such
cooling coils tend to generate moisture. It is therefore preferable
to include a UVC source adjacent to such cooling coils. Similarly,
it may be appropriate to include a UVC source immediately upstream
from a filter/diffuser (not shown) from which the air enters into a
substantially enclosed space, e.g., an IVF laboratory or other
room, after leaving the air purifier 2.
[0033] Downstream from the UV filtration 32 is VOC post-filtration
46, which capture, e.g., VOC by-products of the irradiation from
the UV filtration 32. Possible embodiments of the VOC
post-filtration 46 include any of those discussed supra regarding
the VOC pre-filtration 18. The VOC post-filtration 46 shown in
FIGS. 3 and 4 includes left and right VOC post-filters 48,50 that
are arranged in a V-bank along a horizontal plane (e.g., the plane
of FIG. 4). The VOC post-filters 48,50, like their upstream
counterparts, are preferably blended carbon and KMnO.sub.4.
Although VOC post-filtration 46 is preferred, in some applications,
it may not be required and may thus be omitted.
[0034] Gametes and the human embryo are highly sensitive to VOCs,
even in amounts considered negligible in other applications. It is
therefore essential that the VOC filtration (both pre-filtration 18
and post-filtration 46) operates effectively to remove VOCs from
air that is fed into an environment in which IVF is being
conducted. Accordingly, one or more sensors for detecting VOC
levels (not shown), preferably in real time, may be placed in an
IVF laboratory and coupled to a monitor (not shown) to indicate the
VOC levels in the laboratory at a given time. With such in-room VOC
detection, a user of the air purifier 2 would know when it is time
to replace the VOC pre-filtration 18 and post filtration 46, and/or
whether an alternative type or blend of VOC filters would be more
suitable. While in-room VOC detection is particularly useful in an
IVF laboratory, it may be helpful in any environment requiring low
VOC levels.
[0035] Downstream from the VOC post-filtration 46 is final
particulate filtration 52, which traps substantially all remaining
particulate in the air before the air exits the outlet 8. Final
particulate filtration 52 preferably includes one or more filters
capable of trapping fine airborne particulate, e.g., filters having
a MERV of 13 or greater with an average ASHRAE Dust Spot Efficiency
(Std. 52.1) of 80% or greater. More preferably, such filters have a
MERV of 16 or greater with an average ASHRAE Dust Spot Efficiency
(Std. 52.1) of 95% or greater. Most preferably, such filters have a
MERV of 17 or greater with an average ASHRAE Dust Spot efficiency
(Std. 52.1) of 99.97%, as do high efficiency particulate air
("HEPA") filters. Alternatively, ultra low particulate air ("ULPA")
filters may be suitable. The choice of filter(s) for final
particulate filtration should be guided by the potentially
competing needs of maintaining an optimal air flow rate and
effectively removing particulate from the air.
[0036] The final particulate filtration 52 of FIGS. 3 and 4
includes left and right 12-inch thick HEPA filters 54,56.
Preferably, magnehelic gauges (not shown) are placed both upstream
and downstream from the HEPA filters 54, 56 to measure the pressure
drop across those filters. The degree of pressure drop will assist
in the identification of the proper time in which to change the
HEPA filters 54,56, or other filters used for final particulate
filtration.
[0037] Downstream from the final particulate filtration 52, is an
atomizing humidifier 58. The humidifier 58 may or may not be
necessary, depending on the needs of the facility in which the air
purifier 2 is being used. However, if a humidifier 52 is needed, it
should be placed downstream from the final particulate filtration
52 so that the moisture does not adversely affect the performance
of the VOC post-filters 48,50, the HEPA filters 54,56, or other
filters used for final particulate filtration. Humidified air can
contain and support the growth of biological contaminants.
Accordingly, if a humidifier 58 is used, an additional UVC source
(not shown) to destroy such contaminants should also be included.
This additional UVC source should be downstream from the humidifier
58, preferably at the last point in ductwork before entry into a
room served by the purified air.
[0038] An air purifier according to the present invention, such as
that described in detail, supra, will produce air characterized by
very high purity, suitable for airborne contaminant-sensitive
environments such as IVF laboratories or other medical
environments, for example. That said, an air purifier according to
the present invention is not limited to IVF or other medical
applications. It may be adapted for use in any substantially
enclosed environment, including, but not limited to, homes,
residential buildings, commercial buildings, hotels, cars, buses,
trains, airplanes, cruise ships, educational facilities, offices,
and government buildings. The invention may also have applications
in, e.g., national security, defense, or airline industries. The
desired purity of the air may vary depending on application and
environment. An air purifier according to the present invention,
such as that described in detail, supra, may be adapted accordingly
to achieve a desired level of purity. The sequence and type of air
filtration media in an air purifier according to the present
invention provides air characterized by a purity that was
unattainable with prior devices.
[0039] Accordingly, another aspect of the present invention
includes purified air, such as that attainable using an air
purifier as described herein. Ideally, such purified air would be
characterized by a high level of purity as measured by three
parameters: (a) "TVOC," i.e., total volatile organic compounds,
measured in "ppb," or parts per billion; (b) "Biologicals," i.e.,
biological contaminants, including spores, measured in
"CFU/M.sup.3," or colony forming units per cubic meter; and (c)
"Particulate," i.e., the number of particles per cubic foot having,
e.g., nominal sizes of 0.3 .mu.m or 0.5 .mu.m.
[0040] TVOC measurements maybe made, e.g., using GRAY WOLF SENSING
SOLUTIONS, Model No. TG-502 Toxic Gas Probe with Photo Ionization
Detector ("HD") sensors utilizing a 10.6 eV lamp calibrated to
Isobutylene. The lowest detectable limit of TVOCs using the TG-502
Toxic Gas Probe is 5 ppb.
[0041] To ensure accuracy, measurements of Biologicals are
preferably assessed using two complementary methods. According to a
first method of measuring Biologicals, ambient air (i.e., the air
being tested) is drawn over ALLERGENCO D spore traps using a high
volume vacuum pump calibrated to draw 15 liters of air per minute.
This is done for 10 minutes, so that a total of 150 liters of air
is drawn through the spore trap cassette. The traps are then
examined by direct light microscopic observation to determine the
identification of some select types of biological contaminants
present in terms of CFU/M.sup.3. According to a second method of
measuring Biologicals, an ANDERSON N6 sampler is utilized to obtain
culturable air samples (from the ambient air being tested) on three
types of media: malt extract agar, cellulose agar and DG-18. The
sampler is calibrated pre- and post-collection to draw a rate of
28.3 liters per minute for a sample time of 5 minutes. Using this
second method of measuring Biologicals enables determination of the
unique identification of any biological contaminant present in
terms of CFU/M.sup.3 due to the three different types of growth
media.
[0042] The particulate measurements may be made, e.g., using a TSI
AEROTRAK 9306 Handheld Particle Counter. The particle counter is
preferably calibrated with NIST traceable PSL spheres using TSI's
Classifier and Condensation Particle Counters, the recognized
standard for particle measurements. The particle concentrations in
the air are measured at nominal particle sizes of 0.3 .mu.m, 0.5
.mu.m, 1.0 .mu.m, 3.0 .mu.m, 5.0 .mu.m, and 10.0 .mu.m, per cubic
foot (ft.sup.3).
[0043] In a preferred embodiment, it is contemplated that purified
air attainable using an air purifier as described herein, is
characterized by: (a) a TVOC content of less than 5 ppb (or below
detectable limits using the GRAY WOLF SENSING SOLUTIONS, Model No.
TG-502 Toxic Gas Probe with ND sensors described supra, or another
instrument with similar measurement capabilities and tolerances);
(b) a Biologicals content of less than 1 CFU/M.sup.3 (or below
detectable limits using the methods of measuring Biologicals
described supra, or other methods with similar measurement
capabilities and tolerances); and (c) a particulate content of from
about 1,000 0.3 .mu.m particles per ft.sup.3 of air to about 10,500
0.3 .mu.m particles per ft.sup.3 of air, or from about 600 0.5
.mu.m particles per ft.sup.3 of air to about 1,000 0.5 .mu.m
particles per ft.sup.3 of air.
[0044] Depending on the application or environment, acceptable
levels of TVOCs, Biologicals and particulates may vary. For
example, in one embodiment, the purified air may be characterized
by: (a) a TVOC content of from less than 5 ppb to about 500 ppb;
(b) a Biologicals content of from less than 1 CFU/M.sup.3 to 150
CFU/M.sup.3; and (c) a particulate content of from about 1,000 0.3
.mu.m particles per ft.sup.3 of air to about 50,000 0.3 .mu.m
particles per ft.sup.3 of air, or from about 600 0.5 .mu.m
particles per ft.sup.3 of air to about 500,000 0.5 .mu.m particles
per ft.sup.3 of air. More preferable particulate content is from
about 1,000 0.3 .mu.m particles per ft.sup.3 of air to about 30,000
0.3 .mu.m particles per ft.sup.3 of air, or from about 600 0.5
.mu.m particles per ft.sup.3 of air to about 10,000 0.5 .mu.m
particles per ft.sup.3 of air. Particularly preferred particulate
content is from about 1,000 0.3 .mu.m particles per ft.sup.3 of air
to about 10,500 0.3 .mu.m particles per ft.sup.3 of air, or from
about 600 0.5 .mu.m particles per ft.sup.3 of air to about 1,000
0.5 .mu.m particles per ft.sup.3 of air.
[0045] Another aspect of the invention includes providing purified
air to an IVF laboratory to improve IVF clinical pregnancy rates
and/or implantation rates. The clinical pregnancy rate refers to
the presence of a fetal heart beat within an intrauterine sac. The
implantation rate refers to the ability of a single embryo to
implant within the uterus and develop a fetal heartbeat. A method
of the present invention may comprise providing purified air, such
as air as characterized supra, to an IVF laboratory, performing
multiple cycles of IVF in the laboratory, and achieving a clinical
pregnancy rate equal to or greater than 50% and/or an implantation
rate of equal to or greater than 35% based on a minimum patient
population of 20 patients. In one embodiment, it is contemplated
that achievable clinical pregnancy rates would be from 50% to 70%
and more preferably from 60% to 70%. In another embodiment, it is
contemplated that achievable implantation rates would be from 35%
to 40%.
[0046] Various aspects of the invention will be illustrated in more
detail with reference to the following Examples, but it should be
understood that the present invention is not deemed to be limited
thereto.
EXAMPLES
[0047] Prior to the air purifier described herein, the national
average for clinical pregnancy rates was approximately 38%. Couples
often had to complete multiple cycles of IVF to conceive because
the overall success rates were relatively low. As discussed supra,
the cost of a single IVF cycle is high and multiple cycles are cost
prohibitive to many. Accordingly, there has been a strong and
long-felt need--essentially since the advent of IVF approximately
30 years ago--to significantly improve IVF clinical pregnancy rates
in order to make IVF a more viable option for infertility
patients.
[0048] Prior to invention of the air purifier described herein, the
inventor found that IVF laboratory air quality was not conducive to
the successful growth of an embryo, even if extant filtration
systems were utilized. Extant air filtration systems did not
deliver the air quality necessary to support the human embryo and
thus did not noticeably improve IVF clinical outcomes. In addition,
extant air filtration systems did not protect the IVF laboratory
against varying concentrations of airborne contaminants from the
outside or source air. For example, if a nearby road or roof was
being tarred, the toxic chemicals released would potentially enter
the source air and the IVF laboratory and thus, impact the
developing embryos.
[0049] Below are examples of how the air purifier described herein
provides significant improvements in the art, representing
surprising and unexpected results and satisfaction of a long-felt
and unmet need. The examples compare the air purifier described
herein with extant air filtration systems, including the Coda.RTM.
System and Zandair System. The Coda.RTM. System and Zandair System
have been the primary air filtration systems used in IVF
laboratories for at least the last ten years.
Example 1
[0050] An embodiment of the air purifier described herein was
installed in an IVF laboratory beta site. Prior to that
installation, the laboratory used two Coda.RTM. Systems. Each
Coda.RTM. System included, from an upstream towards a downstream
direction: (1) particulate filtration; (2) carbon and KMnO4
filtration; and (3) HEPA filtration. Prior to installation of the
aforementioned embodiment of the air purifier, clinical pregnancy
rates at the laboratory were 36.4%, which is near the national
average of about 38%. The embodiment of the air purifier described
herein that was installed in the laboratory included, from an
upstream towards a downstream direction: (1) particulate filtration
(located upstream in the air handler unit); (2) carbon and
KMnO.sub.4 filtration; (3) UV filtration; (4) carbon and KMnO4
filtration; and (5) HEPA filtration. After installation of the
aforementioned embodiment of the air purifier, clinical pregnancy
rates at the laboratory jumped to 67.4% based on a patient
population of 191 patients--representing significant and surprising
results in clinical outcomes and patient care.
[0051] "Before" and "after" IVF implantation rates at the
laboratory were also measured. Prior to installation of the
aforementioned embodiment of the air purifier, the implantation
rate at the laboratory was 21% and the national average was 26.1%.
After installation of the aforementioned embodiment of the air
purifier, the implantation rate at the IVF laboratory beta site
increased to 39% based on a patient population of 191
patients--representing significant and surprising results in
clinical outcomes and patient care. The significant and surprising
increase in implantation rates has allowed the program at the
laboratory to return fewer embryos per patient thus reducing the
chance of multiple pregnancies (e.g., twins, triplets, etc.) and
improving the overall obstetrical outcome.
[0052] In sum, these significant improvements in both clinical
pregnancy rates and implantation rates demonstrate that the
aforementioned embodiment of the air purifier described herein
achieved unexpected results relative to the closest prior art and
satisfied a long-felt and unmet need.
Example 2
[0053] The following three charts provide data from independent
third party testing of air quality in an IVF laboratory. Common to
all three charts is the following terminology: (1) "Source
Air"--the air going into an IVF laboratory prior to entering a
respective filtration system; (2) "IVF Laboratory"--the ambient air
within the IVF laboratory; (3) "TVOC"--total volatile organic
compounds, measured in "ppb," or parts per billion; (4)
"Biologicals"--biological contaminants, including spores, measured
in "CFU/M.sup.3," or colony forming units per cubic meter; and (5)
"Particulate"--the number of particles per cubic foot having
nominal sizes of 0.3 .mu.m and 0.5 .mu.m. These measurements were
made using measuring devices and techniques described supra.
TABLE-US-00001 CHART NO. 1 IVF Laboratory Using Two (2) CODA Air
Filtration Systems Source Air IVF Laboratory TVOC 1324 ppb 1372 ppb
Biologicals 469 CFU/M.sup.3 1778 CFU/M.sup.3 Particulate 2,318,663
11,642 0.3 .mu.m 0.3 .mu.m particles per ft.sup.3 particles per
ft.sup.3 1,874,789 9,421 0.5 .mu.m 0.5 .mu.m particles per ft.sup.3
particles per ft.sup.3
[0054] Chart No. 1 compares the source air quality versus the IVF
laboratory air quality where the IVF laboratory air had been
subjected to two Coda.RTM. Systems, as they are described in
Example 1, supra. As Chart No. 1 shows, the air in the IVF
laboratory actually had higher levels of TVOC and biological
contaminants (including spores) than did the source air. Only the
levels of particulates dropped between the source air and the IVF
laboratory air.
TABLE-US-00002 CHART NO. 2 IVF Laboratory Using Three (3) Zandair
Filtration Systems Source Air IVF Laboratory TVOC 594 ppb 1030 ppb
Biologicals 28 CFU/M.sup.3 113 CFU/M.sup.3 Particulate 380,098
5,722 0.3 .mu.m 0.3 .mu.m particles per ft.sup.3 particles per
ft.sup.3 1,695,377 41,472 0.5 .mu.m 0.5 .mu.m particles per
ft.sup.3 particles per ft.sup.3
[0055] Chart No. 2 compares the source air quality versus the IVF
laboratory air quality where the IVF laboratory air had been
subjected to three Zandair Systems. Each Zandair System included,
from an upstream towards a downstream direction: (1) carbon
filtration; (2) HEPA filtration; and (3) photo-catalytic oxidation
along with UV filtration. As Chart No. 2 shows, the air in the IVF
laboratory actually had higher levels of TVOC and biological
contaminants (including spores) than did the source air. Only the
levels of particulates dropped between the source air and the IVF
laboratory air.
TABLE-US-00003 CHART NO. 3 IVF Laboratory Using a Single (1)
Embodiment of Applicant's Air Purifier Described Herein Source Air
IVF Laboratory TVOC 1400 ppb Less than 5 ppb Biologicals 15,240
CFU/M.sup.3 Less than1 CFU/M.sup.3 Particulate 1,063,435 5,410 0.3
.mu.m 0.3 .mu.m particles per ft.sup.3 particles per ft.sup.3
98,763 625 0.5 .mu.m 0.5 .mu.m particles per ft.sup.3 particles per
ft.sup.3
[0056] Chart No. 3 compares the source air quality versus the IVF
laboratory air quality where the IVF laboratory air had been
subjected to only a single embodiment of the air purifier described
herein. The aforementioned embodiment of the air purifier included,
from an upstream towards a downstream direction: (1) particulate
filtration (located upstream in the air handler unit); (2)
carbon/KMnO4 filtration; (3) UV filtration; (4) carbon/KMnO4
filtration; and (5) HEPA filtration. As shown in Chart No. 3,
unlike the air quality results for the two Coda.RTM. Systems and
the three Zandair Systems provided in Chart Nos. 1 and 2
respectively, the single aforementioned embodiment of the air
purifier significantly improved air quality with respect to all
three measured endpoints, i.e., (1) TVOC; (2) Biologicals; and (3)
Particulate.
[0057] The Coda.RTM. System and Zandair System have been the
primary air filtration systems used in IVF laboratories for at
least the last ten years. The independent third party testing
results provided in Chart Nos. 1, 2 and 3 demonstrate that the air
purifier described herein provided markedly superior air purity
compared to the primary air filtration systems used in IVF
laboratories for at least the last ten years. The superior air
purity generated by the air purifier described herein is
surprising. Also surprising are the significantly improved clinical
pregnancy rates and implantation rates described in Example 1,
supra, resulting from the superior air purity generated by the air
purifier described herein.
[0058] Taken together, Examples 1 and 2 demonstrate that performing
IVF in ambient air that has been purified to levels disclosed
herein for three parameters--TVOCs, Biologicals and
Particulate--unexpectedly and significantly improve IVF clinical
pregnancy rates and implantation rates. In addition, given that IVF
has existed for approximately 30 years and that the Coda.RTM.
System and Zandair System have been the primary air filtration
systems used in IVF laboratories for at least the last ten years,
there has been a long-felt and unmet need for an improved air
purifier for, among other things, IVF applications. The air
purifier described herein has satisfied that need.
Example 3
[0059] An embodiment of the air purifier described herein was
installed in an IVF laboratory beta site. This embodiment included,
from an upstream towards a downstream direction: (1) particulate
filtration (located upstream in the air handler unit); (2) carbon
and KMnO.sub.4 filtration; (3) UV filtration; (4) carbon and KMnO4
filtration; and (5) HEPA filtration.
[0060] A catastrophic load of VOCs was accidentally introduced into
the building that housed the IVF laboratory. In particular, a
contractor had poured floor sealant on a large floor surface area
in a room just adjacent to the IVF laboratory. The floor sealant
comprised 10% xylene and 40% acetone. Both xylene and acetone are
highly embryotoxic. While staff outside of the IVF laboratory
developed nausea and intense headaches from the fumes, the
aforementioned embodiment of the air purifier protected the embryos
and staff within the IVF laboratory. TVOC testing before and during
the accident demonstrated that despite over 6000 ppb TVOCs
immediately outside of the laboratory--an extremely high level--the
TVOC levels did not change within the laboratory.
[0061] In sum, the significant and surprising results of
Applicant's air purifier, as demonstrated in Examples 1, 2 and 3,
were surprising and unexpected to the inventor and would be
surprising and unexpected to persons of ordinary skill in the art.
Those examples also help demonstrate how Applicant's air purifier
has satisfied a long-felt and unmet need for an improved air
purifier which allows for significantly improved clinical pregnancy
rates and implantation rates.
[0062] While the invention has been described in detail and with
reference to specific examples thereof, it will be apparent to one
skilled in the art that various changes and modifications can be
made therein without departing from the spirit and scope
thereof.
* * * * *