U.S. patent application number 15/953980 was filed with the patent office on 2018-08-23 for apparatus and method for sanitizing articles.
The applicant listed for this patent is Earl Yerby. Invention is credited to Earl Yerby.
Application Number | 20180236115 15/953980 |
Document ID | / |
Family ID | 48142939 |
Filed Date | 2018-08-23 |
United States Patent
Application |
20180236115 |
Kind Code |
A1 |
Yerby; Earl |
August 23, 2018 |
APPARATUS AND METHOD FOR SANITIZING ARTICLES
Abstract
An apparatus is provided for sanitizing an article, the
apparatus comprising a housing defining an enclosed internal
chamber and having an opening at a door side into the chamber. A
door is configured to selectively close the door side of the
housing for substantially sealing the chamber. A UV light source is
disposed internally of the housing for irradiating the chamber, and
an electronic circuit is electrically connected to the UV light
source and adapted to power the UV light source for a predetermined
period of time. A reflector unit is disposed on one of the walls,
the reflector unit including a reflective section projecting
outwardly at an angle with respect to the wall. With the article
placed in the chamber and the door closed and the electronic
circuit activated, the UV lamp is illuminated for the predetermined
period of time for sanitizing the article.
Inventors: |
Yerby; Earl; (Apex,
NC) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Yerby; Earl |
Apex |
NC |
US |
|
|
Family ID: |
48142939 |
Appl. No.: |
15/953980 |
Filed: |
April 16, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15082027 |
Mar 28, 2016 |
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15953980 |
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13431632 |
Mar 27, 2012 |
9295741 |
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15082027 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61L 2/24 20130101; A61L
2/10 20130101; A61L 2/26 20130101; A61L 2202/122 20130101 |
International
Class: |
A61L 2/10 20060101
A61L002/10 |
Claims
1. An apparatus for sanitizing an article, the apparatus
comprising: a housing including a plurality of walls defining an
enclosed internal chamber and having an opening at a door side into
the chamber; a door configured to selectively close the door side
of the housing for substantially sealing the chamber; a UV light
source disposed internally of the housing for irradiating the
chamber; an electronic circuit electrically connected to the UV
light source and adapted to power the UV light source for a
predetermined period of time; and a reflector unit disposed on at
least one of the walls, the reflector unit including a reflective
section projecting outwardly at an angle with respect to the at
least one of the walls, wherein with the article placed in the
chamber and the door closed and the electronic circuit activated
the UV lamp is illuminated for the predetermined period of time for
sanitizing the article.
2. The apparatus for sanitizing an article as recited in claim 1,
further comprising a tray configured to be received in the chamber
of the housing, the adapted for supporting the article.
3. The apparatus for sanitizing an article as recited in claim 2,
wherein the tray comprises a wire mesh.
4. The apparatus for sanitizing an article as recited in claim 1,
wherein the UV light source provides an intensity of about 7200
.mu.W/cm.sup.2 of UV light at about one foot.
5. The apparatus for sanitizing an article as recited in claim 1,
the reflective section of the reflector unit is angled with respect
to the wall by at least about 135 degrees.
6. The apparatus for sanitizing an article as recited in claim 1,
wherein the plurality of the walls of the housing comprises a front
wall and an opposite rear wall, a pair of side walls
interconnecting the front wall and the rear wall, a floor
interconnecting the lower edges of the front wall, the rear wall
and the side walls, and a ceiling interconnecting the upper edges
of the front wall, the rear wall and the side walls.
7. The apparatus for sanitizing an article as recited in claim 6,
wherein the UV light source extends along the rear wall.
8. The apparatus for sanitizing an article as recited in claim 6,
further comprising a plurality of UV light sources extending along
the plurality of the walls of the housing.
Description
Related Applications
[0001] This application is a continuation application of U.S.
patent application Ser. No. 15/082,027, filed Mar. 28, 2016, which
is a continuation application of U.S. patent application Ser. No.
13/431,632, filed Mar. 27, 2012, now U.S. Pat. No. 9,295,741, the
contents of both of which are incorporated herein by reference.
[0002] This application is related to U.S. patent application Ser.
No. 12/512,766, filed on Jul. 30, 2009, now U.S. Pat. No.
8,143,596, which claims the benefit of U.S. Provisional Patent
Application No. 61/268,365, filed on Jun. 11, 2009, all of which
applications and patent are incorporated herein by reference in
their entirety.
BACKGROUND
[0003] An apparatus and method for sanitizing articles is described
and, more particularly, an apparatus and method using ultraviolet
light for sanitizing articles between uses, such as medical
instruments, tools and objects, patient-care items, and the
like.
[0004] Ultraviolet (UV) light of a particular range of wavelengths,
intensities, and durations can kill or inhibit growth of
microorganisms. Specifically, ultraviolet radiation in the range of
200 nanometer (nm) to 300 nm is effective against airborne and
surface bacteria, viruses, yeasts, and molds. For most
microorganisms, the peak inactivation wavelength is at or about 260
nm. Mercury lamps produce UV light very efficiently at 254 nm and,
therefore, this wavelength has become the standard UV germicidal
light wavelength.
[0005] UV light is used in healthcare facilities to disinfect
surgical theaters and operating rooms. UV light is also used
extensively in air and water purification applications in the food
and beverage industry and in sewage treatment. UV light can also be
used to disinfect patient-contact items like stethoscopes,
thermometers, blood pressure cuffs, and oximeters, as well as
doctor and staff-carried items such as cell phones, eMARs scanners,
penlights, scissors, PDAs/tablets/laptops, and other easily
contaminated, and difficult-to-disinfect items. UV light can also
disinfect hand-held and portable electronic devices and other
personal articles, including mobile (cellular) telephones, portable
music and video players (e.g., MP3 and MP4 players), cameras,
portable global positioning devices, and the like.
[0006] In conventional UV sanitization devices, the UV radiation
sources are stationary or portable and can range in size from very
large devices to small hand-held wands. However, a problem
associated with UV sanitization is most articles or implements
requiring sanitization will have interior spaces and non-planar
surfaces. Some will have multiple invaginations which can harbor
microbes, such as reusable grocery bags, sporting equipment
including helmets and shoes, and the like. Typically, UV
sanitization devices are inadequate to irradiate the non-planar
surfaces of articles at varying distances from the UV radiation
sources. As a result, some surfaces of the articles are not reached
by UV irradiation.
[0007] For the foregoing reasons, there is a need for a new device
for sanitizing articles, particularly articles having an interior
space and non-planar surfaces that are difficult to reach with
conventional UV irradiation.
Summary
[0008] An apparatus is provided for sanitizing an article, the
apparatus comprising a housing including a plurality of walls
defining an enclosed internal chamber and having an opening at a
door side into the chamber. A door is configured to selectively
close the door side of the housing for substantially sealing the
chamber. A UV light source is disposed internally of the housing
for irradiating the chamber, and an electronic circuit is
electrically connected to the UV light source and adapted to power
the UV light source for a predetermined period of time. A reflector
unit is disposed on at least one of the walls, the reflector unit
including a reflective section projecting outwardly at an angle
with respect to the at least one of the walls. With the article
placed in the chamber and the door closed and the electronic
circuit activated, the UV lamp is illuminated for the predetermined
period of time for sanitizing the article.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] For a more complete understanding of the present invention,
reference should now be had to the embodiments shown in the
accompanying drawings and described below. In the drawings:
[0010] FIG. 1 is a front perspective view of an embodiment of a
device for sanitizing articles with a door in a closed
position.
[0011] FIG. 2 is a front elevation view of the sanitizing device
shown in FIG. 1 with the door in an open position.
[0012] FIG. 3A is a longitudinal cross-section view of the
sanitizing device shown in FIG. 1 taken along line 3A-3A of FIG.
2.
[0013] FIG. 3B is a longitudinal cross-section view of the
sanitizing device shown in FIG. 3A with the mesh cages removed.
[0014] FIG. 4 is a close-up cut-away perspective view of an
embodiment of reflector units on a bottom surface of the sanitizing
device shown in FIG. 2.
[0015] FIG. 5 is a cross-section view of the sanitizing device
shown in FIG. 1 taken along line 5-5 of FIG. 2.
[0016] FIG. 6 is a side elevation view of an embodiment of a
reflector unit for use in the sanitizing device shown in FIG.
1.
[0017] FIG. 7 is a cross-section view of the sanitizing device
shown in FIG. 1 taken along line 7-7 of FIG. 2.
[0018] FIG. 8 is a perspective of an embodiment of a tray for use
in the sanitizing device shown in FIG. 1.
[0019] FIG. 9 is a rear elevation view of the sanitizing device
shown in FIG. 1 with a partial cover panel removed.
[0020] FIG. 10 is a top plan view of the sanitizing device shown in
FIG. 1.
DESCRIPTION
[0021] Certain terminology is used herein for convenience only and
is not to be taken as a limitation on the invention. For example,
words such as "upper," "lower," "left," "right," "horizontal,"
"vertical," "upward," and "downward" merely describe the
configuration shown in the FIGs. Indeed, the components may be
oriented in any direction and the terminology, therefore, should be
understood as encompassing such variations unless specified
otherwise.
[0022] As used herein, the term "article" is deemed to mean any
portable, potentially contaminated object or item of porous or
non-porous material suspected to be a fomite or vector of pathogens
and disease transmission.
[0023] As used herein, the terms "bulb" or "lamp" is deemed to mean
any source of UV light.
[0024] As used herein the terms "disinfect" and "sanitize" is
deemed to mean the expectation that bacterial count will be
substantially reduced on objects and items irradiated with UV
light.
[0025] As used herein, the term "reflector unit" means a collection
of reflective structures that together reflect at least 60% of
light having a frequency between 100 nm to 290 nm.
[0026] A device for sanitizing an article is shown in FIG. 1 and
generally designated at 20. The sanitizing device 20 comprises a
housing 22 constructed of a material that is impervious to UV
radiation. In one embodiment, the housing 22 is formed from
polished, reflective aluminum sheeting. The housing 22 is
substantially cube-like in shape, including a partial front wall 24
defining an opening 26, side walls 28, and an inner rear wall 30
and an outer rear wall 31 (not visible in FIG. 1). The walls 24,
28, 30, 31 of the housing 22 are joined adjacent their edges by a
ceiling 32, a roof 35 spaced from the ceiling and a floor 34. The
opening 26 in the front wall 24 is sealed by a sliding tambour door
36, which provides access to inside the housing 22. Optionally, the
housing 22 can include a UV-resistant viewing window 39 that allows
a user to view the inside of the sanitizing device 20 during
operation while avoiding exposure to UV radiation. The housing 22
is sized and shaped to receive an article to be sanitized. The
dimensions of the housing 22 may be determined by the field of use.
In the embodiment shown in the FIGs., the sanitizing device 20 may
be placed on a cart 37 for mobility of the device. Alternatively,
the sanitizing device 20 can be mounted to a wall or placed on a
table or on the ground. It is understood that the size of the
housing 22 or the opening 26 can vary depending on the article to
be disinfected. All commercially viable sizes are contemplated.
[0027] Referring to FIG. 2, the housing 22 defines an open interior
chamber 38 formed by the inner surfaces of the front and side walls
24, 28, the inner surface of the inner rear wall 30, and inner
surfaces of the ceiling 32 and the floor 34. The opening 26 in the
front wall 24 allows the user to access the chamber 38 for
inserting and removing articles to be sanitized. The chamber 38 is
configured to accommodate at least one source of UV radiation with
a wavelength and intensity suitable for sanitization of the
article. The sanitizing device 20 may further comprise one or more
means for supporting articles to be sanitized. In addition, one or
more reflector units 40 project upwardly from the floor 34 for
reflecting UV light from the UV lamps 42 upwardly toward the
articles disposed within the chamber 38. As described in more
detail below, the reflector units 40 provide a more thorough and
uniform distribution of UV light to all surfaces within the chamber
38, and in particular, the underside of the article supporting
means and the articles.
[0028] The door 36 is made of, or includes a layer, lining, or
coating of, a material that is substantially opaque to UV
radiation. The door 36 is slidingly received in a track 44 formed
in the front wall 24 of the housing 22 (FIGS. 3A and 3B). The door
36 is slideable in the track 44 for moving between an open position
(FIG. 2) wherein articles can be inserted into, or removed from,
the chamber 38, and a closed position (FIG. 1) wherein the chamber
38 is closed so as to substantially prevent the escape of
ultraviolet radiation from the chamber 38. A handle 46 of
antimicrobial copper alloy may be provided on the door 36 for
moving the door 36 between the open position and the closed
position. A suitable light seal can be provided at a junction where
the front wall 24 of the housing 22 and the leading edge of the
door 36 engage when the door 36 is in the closed position. The seal
may include any suitable material which inhibits the passage of
light, such as a rubber or a felt gasket, or the door 36 may have a
close or overlying fit between the door 36 and the front wall 24 of
the housing 22.
[0029] Although the door 36 is shown as a tambour door, it is
contemplated that the door 36 could alternatively be a hinged door
or any other commercially suitable configuration. For example, the
hinged door may be attached to the housing 22 by hinges disposed
between the adjacent edges of the housing 22 and the door that
allows the door to be selectively opened and closed.
[0030] The inner surfaces of the walls 24, 28, 30, the floor 34 and
the ceiling 32 of the housing 22 are provided with a reflective
material. A suitable material is aluminum, and more particularly,
polished aluminum. Other metals may be used, such as polished zinc
or stainless steel. Alternatively, a reflective coating may be
placed on the inner surfaces of the walls 24, 28, 30, floor 34 and
ceiling 32, such as magnesium carbonate. The reflective surfaces
reflect the emitted UV radiation in order to ensure that all
surfaces of the article to be irradiated receive comparable amounts
of UV irradiation. In practice, a reflectivity in excess of 65% is
desirable. In one embodiment, a polished aluminum can achieve up to
97% reflectivity, a polished zinc surface can achieve about 80%
reflectivity, while the correct selection of magnesium
carbonate/oxide coating can achieve about 70% reflectivity. The
reflective inner surfaces of the walls 24, 28, 30, the floor 34 and
the ceiling 32 of the housing 22 can be smooth, or if desired, may
be a sculptured or otherwise non-planar configuration to enhance or
direct the reflected radiation. In one embodiment, the inside
surface of the door 36 may also be provided with a reflective
material.
[0031] As shown in FIGS. 4 and 5, the floor 34 of the housing 22
includes a plurality of spaced reflector units 40. Referring to
FIG. 6, each of a pair of sides of a reflector unit 40 includes at
least three sections, a primary wall section 48, a first end wall
section 50, and a second end wall section 52. The first and second
end wall sections 50, 52 extend angularly inwardly from the primary
wall section 48. Each of the three wall sections 48, 50, 52
extending upwardly from the floor 34 and are disposed off normal
with respect to the floor 34. The angle (H) between the floor 34 of
the housing 22 and each of the wall sections 48, 50, 52 is at least
about 135 degrees. The wall sections 48, 50, 52 are joined at an
apex of the reflector unit 40 forming an elongated pyramidal
projection such that, when viewed from the front, the reflector
unit 40 appears to have a triangular shape. In alternative
embodiments, the reflector unit 40 could include four or more wall
sections and be formed of shapes such that, when viewed from the
front, the reflector unit 40 appears to have a square, rectangular,
pentagonal, hexagonal, or any other commercially viable shape. Of
course, depending on the shape of the reflector unit 40, the shape
and number of reflective wall sections will likely vary.
[0032] The reflector units 40 can be composed of the same
reflective material as the inner surfaces of the walls 24, 28, 30
of the housing 22. Alternatively, the reflector units 40 can be one
or more commercially suitable materials, including, for example,
mirrors, powder-coated and other metal sheets. The reflective wall
sections 48, 50, 52 could also be dimpled or bumpy.
[0033] The reflector units 40 are positioned on the floor 34 with
respect to the UV lamps 42 so that at least some UV radiation that
would otherwise be emitted by the UV light sources in a direction
other than at the articles is reflected upwardly toward the
articles. Specifically, the longitudinal axis of the reflector
units 40 adjacent the front and rear of the chamber 38 is aligned
with the mid-line C (FIG. 5) between the side walls 28 of the
chamber. The intermediate V-shaped reflector unit 40 is positioned
such that a line extending between each of the pairs of opposite
corners of the housing 22 would be perpendicular to the primary
wall sections 48 of the intermediate reflector unit 40.
[0034] With this arrangement of the reflector units 40, the UV
radiation intensity on the various surfaces of the article is more
consistent, which increases the efficiency of use of the UV
radiation and maximizes the exposure of all surfaces of the
articles to the UV radiation. The result is a sanitizing device 20
requiring fewer UV lamps 42 and a shorter duration of exposure to
the UV light to disinfect the article. It is understood that the
reflector units 40 can be disposed at any position on the inner
surface of the walls 24, 28, 30, the ceiling 32 or the floor 34 of
the housing 22 to achieve this result. All commercially suitable
configurations for the reflector units 40 are contemplated, and
such configurations will likely depend on the size and dimensions
of the housing 22 and the articles to be irradiated.
[0035] Any commercially suitable source of UV radiation is
contemplated for use with the sanitation device 20. The UV
radiation source may include cold cathode UV tubes, LED's, and low,
medium, or high vapor mercury lamps. The UV radiation source has a
suitable wavelength that falls within the wavelength range of about
220 nm to about 300 nm, preferably at least substantially in the
range of 235 nm to about 280 nm, and more preferably about 250 nm
to about 275 nm. In this range, the UV radiation is highly
effective against microorganisms.
[0036] In the embodiment shown in FIGS. 2, 3B and 7, the source of
UV radiation includes a plurality of elongated fluorescent UV lamps
42 disposed on an inner surface of the housing 22 and positioned to
substantially irradiate the interior chamber 38 and any article in
the chamber. A UV lamp that emits light within the preferred
wavelength range and is suitable for use in the sanitizing device
20 is a Model No. GTL 18 or GTL 24 high output, 72 watt UV
germicidal lamp, available from American Ultraviolet Company of
Lebanon, Ind. These UV lamps are 15 mm glass tubes with a single
end power connector and a protective boot and are Teflon-coated for
containment in case of breakage. In addition, these UV lamps
produce UV light at an intensity of 7200 .mu.W/cm.sup.2 at a
distance of about twelve inches. The UV lamps are approximately 18
inches and 24 inches in length, respectively, including three
inches attributed to the end connectors. Although the UV lamps are
shown having elongated tubular bulbs, it is contemplated that other
commercially suitable sources of UV light could be used of any
convenient size or shape of UV lamp or bulb may be employed. Even a
plurality, or a bank, of UV LED's may be employed, as long as they
emit the proper wavelength of UV light.
[0037] The plurality of UV lamps 42 are attached to pairs of tube
holders 78 and depend from the inside surface of each of the side
walls 28, the inner rear wall 30 and the ceiling 32 of the housing
22. The UV lamps 42 are oriented radially inward towards the center
of the chamber 38 so as to provide UV radiation from all directions
to maximize the exposure of the articles within the chamber 38. The
UV lamps are spaced about 11/2 inches from the inner surfaces of
the housing 22. Two UV lamps 42 are provided on each side wall 28
extending generally vertically and are evenly spaced between the
floor 34 and the ceiling 32. The front UV lamp 42 on each side wall
28 is spaced about 4 inches from the front wall 24, and the rear UV
lamp 42 on each side wall 28 is spaced about 8 inches from the rear
wall 30. The front and rear UV lamps 42 are spaced from each other
about 10 inches on center. The single UV lamp 42 on the rear wall
30 is disposed along the central longitudinal axis of the rear wall
30 and is evenly spaced between the ceiling 30 and the floor 34.
The UV lamp 42 on the ceiling 32 is disposed along the central
longitudinal axis of the ceiling 32 and is evenly spaced between
the front wall 24 and the rear wall 30. The distance from each of
the UV lamps to a central plane passing through the middle of the
chamber 38 is about eleven inches. In one embodiment of the
sanitizing device 20 based on these relative dimensions, the
reflector units 40 may each be about 4 inches in length and project
upwardly about 3/4 inches from the floor 34 of the housing 22. The
front end of the front reflector unit 40 is about 1/2 inches from
the front wall of the housing 22 and the rear end of the rear
reflector unit 40 is about three inches from the rear wall 30. For
the V-shaped reflector unit 40, the length of four inches is
measured from the point of the "V" to each end.
[0038] It is understood that the UV lamps 42 could be disposed at
non-right angles. It is further understood that the specific
number, size, and orientations of each of the UV lamps 42 will
likely vary depending on the size and type of UV lamps used, the
article to be disinfected, and the sizes and dimensions of the
housing 22. The UV lamps 42 can be disposed in any suitable
locations and oriented such that articles within the chamber 38 are
exposed to adequate amounts of UV radiation for sanitization. A
wire mesh protective cage 80 surrounds each of the UV lamps 42.
[0039] The article supporting means may comprise an article support
suitable for use in the environment of the chamber 38, such as a
drawer, tray, shelf system, or receptacles for receiving and
supporting articles within the housing 22. In the embodiment shown
in the FIGs., the article supporting means is a plurality of trays
54 positioned at different levels in the chamber 38. Referring to
FIG. 8, each tray 54 comprises a platform disposed in a flat
configuration. The tray 54 is formed from a light-transmissible
material made of wire mesh or lattice such as, for example, 50 mm
wire mesh. The tray 54 is configured to have some depth thereby
defining a recess for accommodating the article. Opposed channels
56 are provided on the inner surfaces of the side walls 28.
Elongated downwardly curved flanges 57 are positioned on opposite
sides of the trays 54 for slidably receiving the channels 56. A
hook 58 is provided on the back edge of the tray 54. The hook 58
captures the wire mesh of the cage 80 surrounding the UV lamp 42 on
the rear wall 30 to secure the trays 54 in an inserted position.
The trays 54 can be removed for cleaning or for loading articles on
the trays 54.
[0040] The relative positioning of the UV lamps 42, the reflector
units 40, and the trays 54 is such as to ensure that all surfaces
of the article and the upper and lower surfaces of the trays 54 are
exposed to sufficient amounts of UV irradiation through the
apertures of the wire mesh. The effect of "shadows" caused by the
bars of the mesh coming between the lower surface of the article
when supported on the mesh and the UV radiation are minimized. The
channels 56 and flanges 57 are made of reflective material to
further maximize the distribution of UV radiation. A minimal
contact area between the article and the mesh of the tray 54 may be
acceptable.
[0041] Referring now to FIG. 9, the outer surface of the rear wall
30 of the sanitizing device 20 accommodates a control box 60. The
control box 60 preferably has a removable cover panel (not shown)
for allowing access to a circuit board supporting the wiring and
circuitry for repair, removal, and replacement. The circuit board
carries a controller 62 for controlling operation of the sanitizing
device 20 and a power supply 64 for providing power to the
controller 62, such as electric cord and plug (not shown). The
power supply cord 64 is connected to a transformer 66 to provide
electrical power to the circuit. The controller 62 can control the
delivery of power to the UV lamps 42 to be turned on or off, as
well regulating other electrical components of the sanitizing
device 20 including, for example, one or more sensors.
[0042] A first sensor 68 senses or detects whether the door 36 is
in the open position or the closed position and signals the
controller to control operation of the sanitizing device 20
accordingly. Alternatively, a sensor may be activated upon closing
the door. The sensor can include, but is not limited to, one or
more of a depression switch, electrical contacts, an optical sensor
or other sensor known in the art for determining the relative
positions of the door and the front wall 24 of the housing 22. In
one embodiment, the sensor comprises a contact on the housing 22
and a magnet 69 in the door 36, the completed circuit activating
the UV radiation source only when the door 36 is in the closed
position to enclose the chamber 38. For example, the ultraviolet
radiation source is disabled from emitting ultraviolet light when
the door 36 is in the open position and is enabled to emit
ultraviolet light when the door 36 is in the closed position.
[0043] Each UV light source is electrically connected to an
electronic ballast, which provides resistance to stabilize current
in the circuit created when the sanitizing device 20 is attached to
a power source via the power supply cord 64. In a preferred
embodiment, ballast is operational with 100/200 VAC at 50/60
HZ.
[0044] In one embodiment, the controller 62 activates the
ultraviolet radiation source for a first predetermined period of
time when the sensor 68 senses that the door 36 is in the closed
position. The predetermined period of time may vary depending on
the strength of the UV light source. In one embodiment of the
sanitizing device 20 using the 72 watt UV lamps identified above,
it is estimated that between about 30 and about 60 seconds would be
sufficient to eliminate most bacteria present on an article. A
timer is used to control the length of time the UV source is
powered. The controller 62 automatically turns off the UV light
source at the set time on the timer after, for example, the about
30 to about 60 seconds, and may include an audible signal (beep,
chime, etc.) to let the user know the cycle is finished. The
controller may in addition to, or alternately, activate the UV
radiation source based on a signal from a manual interface, such as
a switch 70 (FIG. 1) or other interface located outside of the
sanitizing device 20 that a user can select to manually activate
the controller 62. A plurality of switches may also be provided,
and additional functionality may be included, including different
settings for different articles to be sanitized, different
durations of the sanitization cycle, different power level
intensities for the UV lamps, and the like.
[0045] One or more indicator lamps or displays may be provided on
the outside of the housing 22 to indicate the status of the
sanitizing device 20. For example, a lamp indicator light may show
whether power is being sent to the sanitizing device 20. A light 82
may also be provided in the chamber 38 (FIG. 7), which light 82 is
activated for the user when the door 36 is in the open position.
All other commercially viable safety systems are contemplated. For
example, a vent 84 is provided between the rear walls 30, 31 of the
housing 22 and exits via the roof 35. The sanitizing device 20
could also require a key or security code be entered prior to
activation.
[0046] In operation, the user moves the door 36 to the open
position by rolling upwardly to expose the chamber 38 and the trays
54. The trays 54 are accessed by manually detaching the hooks 58
and pulling the trays 54 outwardly. The trays 54 slide along the
channels 56 and may be completely removed. Articles to be
irradiated are then placed on one or more of the trays 54. The
trays 54 are then returned to the chamber 38 and pushed inwardly to
the closed position by pressing on the front of the trays 54 and
attaching the hooks 58 to the wire mesh of the cage 80. The user
moves the door 36 to the closed position to enclose the articles
within the chamber 38. The sensor 68 is activated upon closing of
the door 36 for signaling the controller 62 that the door is in the
closed position. The sanitizing device 20 is activated by pressing
the outside switch 70. Upon activation, the controller 62 directs
power to energize the UV lamps 42 to sanitize the articles.
[0047] When the sanitization device 20 is activated, UV light is
directed throughout the chamber 38 and onto the articles to be
disinfected. UV light is reflected off of the reflective inner
surfaces of the walls and the surfaces of the reflector units 40
ensuring exposure of all surfaces of the articles to UV light. The
effect is UV light is directed from the UV lamps 42 in all
directions, including irradiating the underside of the articles
through the apertures in the trays 54. The UV light kills
significant amounts of microorganisms that may be on the articles,
thereby sanitizing, or disinfecting, the articles. The articles are
subjected to a dose of UV light corresponding to the UV light
intensity as a function of time and distance of the UV lamps from
the articles. Dose response levels are unique to each
microorganism. Additionally, different wavelengths of UV light have
different inactivation rates depending on the microorganism. It is
understood that such process parameters are predetermined to affect
the amount of radiation such that an article receives UV light
sufficient to destroy microorganisms on the surfaces of the
articles and to ensure a consistently effective reduction in
microbial numbers.
[0048] After a predetermined time sufficient to achieve a desired
level of sanitization, the controller 62 deactivates the UV
radiation sources. When the sanitization cycle is completed, the
display may indicate as such. If the sensor 68 detects an attempt
to open the door 36 while the UV radiation sources are activated,
the controller immediately shuts off power to the UV radiation
sources.
[0049] It is contemplated that the sanitizing device 20 described
and shown herein could be configured to sanitize all manner of
articles and equipment including, for example, cosmetics or
cosmetic implements such as eyeliner brushes and mascara brushes,
and even small cosmetic items themselves such as personal items
including compacts, and the like; kitchen utensils and tools such
as cutting boards, and larger sized items including wheel chairs,
strollers, and other sizes of shopping carts shopping baskets.
Depending on the size and dimension of sanitizing device 20, and
the type of equipment to be disinfected, the number of reflective
units, and their configurations, can be varied. Regardless of the
article to be sanitized, the sanitizing device 20 design allows for
considerable adjustment of the amount of energy striking the
article by selecting the number of lamps used, the distance of
those lamps from the article, and the length of time that the
article is exposed to UV light. The sanitizing device 20 can
conveniently and effectively disinfect articles in a short period
of time.
[0050] The sanitizing device 20 described and shown herein was
tested to determine the efficiency of the sanitizing device 20
versus a concentration of Clostridium difficile (C. difficile),
Staphylococcus aureus (S. aureus), and Acinetobacter baumannii (A.
baumannii) using a 60 second exposure time and a 120 second
exposure time. Microorganism preparation included inoculating
tryptic soy agar (TSA) petri plates with S. aureus and A. baumannii
and incubating the plates for 22-26 hours at 30-35.degree. C.
Similarly, reinforced clostridial medium plus agar (RCM+ Agar)
petri plates were inoculated with C. difficile and incubated for
46-52 hours at 30-35.degree. C. in an anaerobic chamber containing
an AnaeroGen Pak.TM..
[0051] Serial dilutions of each culture were prepared in 7.2 pH
buffer. Next, 0.1 mL of 10.sup.3 CFU/mL concentration of each
organism were plated in duplicate and incubated as described above.
The concentration of each organism was calculated by multiplying
the count acquired by 10 due to the 10.sup.4 CFU/mL dilution being
used for spiking.
[0052] Pre-poured plates were then spiked. Specifically, 18 TSA
plates were inoculated with 0.1 mL of 10.sup.4 CFU/mL of S. aureus
and spread with a sterile hockey stick and another 18 TSA plates
were inoculated with 0.1 mL of 10.sup.4 CFU/mL of A. baumannii and
spread with a sterile hockey stick. Similarly, 18 RCM+ Agar plates
were inoculated with 0.1 mL of 10.sup.4 CFU/mL of C. difficile and
spread with a sterile hockey stick.
[0053] The organism-spiked plates were then placed in the
sanitizing device 20 on each of the top, middle and bottom trays.
On the top tray, plates were placed at the right front, back middle
and left back of the tray. On the middle tray, plates were placed
at the right back, middle and left middle of the tray. On the
bottom tray, plates were placed at the right middle, middle, and
left front of the tray. Lids were removed from the plates and the
plates set agar side up. The sanitizing device 20 was activated for
60 seconds. The sanitizing device was deactivated and the lids
replaced on the plates and the plates removed. These steps were
repeated for each organism.
[0054] In a second run, the organism-spiked plates were in the
sanitizing device 20 on each of the top, middle and bottom trays.
On the top tray, plates were placed at the middle front, left back
and right back of the tray. On the middle tray, plates were placed
at the middle back, middle and left front of the tray. On the
bottom tray, plates were placed at the right front, middle front,
and left back of the tray. Lids were removed from the plates and
the plates set agar side up. The sanitizing device 20 was activated
for 120 seconds. The sanitizing device was deactivated and lids
replaced on the plates and the plates removed. These steps were
repeated for each organism.
[0055] The UV treated plates of S. aureus and A. baumannii were
incubated at 30-25.degree. C. for 44-52 hours. The UV treated
plates of C. difficile were incubated at 30-35.degree. C. for 44-52
hours in an anaerobic jar containing an AnaeroGen Pak.TM.. The
organism spike count from untreated plates served as a positive
control to confirm that TSA and RCM+ Agar media supported the
correct bacterial growth. An un-spiked TSA plate and an un-spiked
RCM+ Agar plate were also incubated to confirm that the plates were
not contaminated.
[0056] The percent kill of each organism for each exposure time was
calculated by dividing the count after the exposure to UV light by
the original concentration of the organism and then multiplying by
100. Log.sub.10 reduction of each organism for each exposure time
was calculated by converting each organism count to a log.sub.10
number. For example, 213 CFU/mL equals 2.33 Log.sub.10. The
Log.sub.10 decrease of each organism for each exposure time was
found by calculating the difference between the Log.sub.10 of the
original concentration of the organism and the Log.sub.10 after the
60 and 120 second exposure to UV.
[0057] The sanitizing device 20 for all plates at all locations and
for both exposure times achieved a 100% killing of S. aureus and A.
baumannii. The sanitizing device 20 for all plates at all locations
and for both exposure times achieved a 100% killing of C.
difficile, except for the middle tray at the middle and left middle
locations, which achieved 99.9% reduction in the organism.
Converting the organism counts to a Log.sub.10 number, the
reduction in S. aureus at all locations was 5.80 log.sub.10 and the
reduction in A. baumannii at all locations was 6.15 log.sub.10 .
Although one colony of was found on two of the C. difficile plates
from the 120 second exposure study, the log.sub.10 of 1 is 0 so the
log.sub.10 reduction for all locations was 4.00.
[0058] Although the apparatus and method for sanitizing articles
has been shown and described in considerable detail with respect to
only a few exemplary embodiments thereof, it should be understood
by those skilled in the art that we do not intend to limit the
invention to the embodiments since various modifications, omissions
and additions may be made to the disclosed embodiments without
materially departing from the novel teachings and advantages of the
invention, particularly in light of the foregoing teachings.
Accordingly, we intend to cover all such modifications, omission,
additions and equivalents as may be included within the spirit and
scope of the invention as defined by the following claims. In the
claims, means-plus-function clauses are intended to cover the
structures described herein as performing the recited function and
not only structural equivalents but also equivalent structures.
Thus, although a nail and a screw may not be structural equivalents
in that a nail employs a cylindrical surface to secure wooden parts
together, whereas a screw employs a helical surface, in the
environment of fastening wooden parts, a nail and a screw may be
equivalent structures.
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