U.S. patent application number 16/747688 was filed with the patent office on 2020-07-23 for light radiation device for medical treatment.
This patent application is currently assigned to SEOUL VIOSYS CO., LTD.. The applicant listed for this patent is SEOUL VIOSYS CO., LTD.. Invention is credited to Hee Ho BAE, A Young LEE, Yeong Min YOON.
Application Number | 20200230435 16/747688 |
Document ID | / |
Family ID | 71609563 |
Filed Date | 2020-07-23 |
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United States Patent
Application |
20200230435 |
Kind Code |
A1 |
BAE; Hee Ho ; et
al. |
July 23, 2020 |
LIGHT RADIATION DEVICE FOR MEDICAL TREATMENT
Abstract
A light radiation device includes a housing, a substrate
provided in the housing, and a light source mounted on the
substrate. The light source includes a first light source including
at least one first light source to emit first light having a blue
wavelength band, a second light source including at least one
second light source to emit second light having a ultraviolet
wavelength band, and a control unit to control the first light
source and the second light source such that the second light
source sequentially emits the second light after the first light
source emits the first light. A dose of the second light source is
less than 1/10 of a dose of the first light source.
Inventors: |
BAE; Hee Ho; (Gyeonggi-do,
KR) ; YOON; Yeong Min; (Gyeonggi-do, KR) ;
LEE; A Young; (Gyeonggi-do, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SEOUL VIOSYS CO., LTD. |
Gyeonggi-do |
|
KR |
|
|
Assignee: |
SEOUL VIOSYS CO., LTD.
Gyeonggi-do
KR
|
Family ID: |
71609563 |
Appl. No.: |
16/747688 |
Filed: |
January 21, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62795730 |
Jan 23, 2019 |
|
|
|
62825993 |
Mar 29, 2019 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61N 2005/0661 20130101;
A61N 2005/0662 20130101; A61L 2/084 20130101; A61L 2/10 20130101;
A61N 5/0624 20130101 |
International
Class: |
A61N 5/06 20060101
A61N005/06; A61L 2/08 20060101 A61L002/08; A61L 2/10 20060101
A61L002/10 |
Claims
1. A light radiation device comprising: a housing; a substrate
provided in the housing; and a light source mounted on the
substrate, wherein the light source includes: a first light source
including at least one first light source and configured to emit
first light having a blue wavelength band; a second light source
including at least one second light source and configured to emit
second light having a ultraviolet wavelength band; and a control
unit that controls light emission of the first light source and the
second light source such that the first light and the second light
are emitted sequentially, or at timings close to each other,
regardless of whether emission of the first light overlaps with
emission of the second light, or not, and wherein a dose of the
second light source is less than 1/10 of a dose of the first light
source.
2. The light radiation device of claim 1, wherein the control unit
controls the first light source and the second light source to emit
the second light after starting to emit the first light.
3. The light radiation device of claim 1, wherein the second light
corresponds to at least one of UVA (ultraviolet A), UVB
(ultraviolet B), and UVC (Ultraviolet C) wavelength bands.
4. The light radiation device of claim 2, wherein the first light
has a wavelength band in a range of about 400 nm to about 500
nm.
5. The light radiation device of claim 1, wherein the first light
further includes light having a wavelength band corresponding to a
visible light.
6. The light radiation device of claim 5, wherein the first light
has a wavelength band in a range of about 380 nm to about 780
nm.
7. The light radiation device of claim 1, wherein the second light
has a wavelength band in a range of about 240 nm to about 280
nm.
8. The light radiation device of claim 7, wherein the first light
is irradiated for a first time, and the second light is irradiated
for a second time shorter than the first time.
9. The light radiation device of claim 8, wherein the second light
starts to be irradiated after the first light stops
irradiation.
10. The light radiation device of claim 8, wherein the second light
starts to be irradiated before the first light stops irradiation,
and at least a portion of the first time and the second time has a
mutually overlapping duration.
11. The light radiation device of claim 8, wherein the first light
is continuously irradiated.
12. The light radiation device of claim 8, wherein the second light
is discontinuously irradiated.
13. The light radiation device of claim 8, wherein the second light
is periodically irradiated.
14. The light radiation device of claim 1, wherein the light
radiation device is used to treat a human body.
15. The light radiation device of claim 14, wherein the light
radiation device is used to treat acute wound.
16. The light radiation device of claim 1, wherein the second light
source emits the second light within a predetermined dose per day,
and the predetermined dose per day is in a harmless range to be an
allowable dose when the second light is applied to a human
body.
17. The light radiation device of claim 16, wherein the second
light is irradiated with a dose in a range of about 30 J/m.sup.2 to
about 1,000,000 J/m.sup.2.
18. A light radiation device for treating a wound, wherein the
light irradiation device comprises: a first light source including
at least one first light source and configured to emit first light
in a blue wavelength band; a second light source including at least
one second light source and configured to emit second light in a
ultraviolet wavelength band; and a control unit that controls the
first light source and the second light source such that the second
light source sequentially emits the second light after the first
light source emits the first light, wherein a dose of the second
light source is less than 1/10 of a dose of the first light
source.
19. The light radiation device of claim 18, wherein the first light
has a wavelength band in a range of about 400 nm to about 500 nm,
and wherein the second light has a wavelength band in a range of
about 240 nm to about 280 nm.
20. The light radiation device of claim 19, wherein the first light
is irradiated for a first time, and the second light is irradiated
for a second time shorter than the first time.
Description
PRIORITY AND CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Applications No. 62/795,730, filed on Jan. 23, 2019, and No.
62/825,993, filed on Mar. 29, 2019, which are hereby incorporated
by reference for all purposes as if fully set forth herein.
RELATED ART
[0002] Embodiments of the present disclosure described herein
relate to a light radiation device, and more particularly, relate
to a light radiation device used for medical treatment.
[0003] Recently, various treatment devices using ultraviolet (UV)
light have been developed. In general, it is well known that the UV
light has a sterilization effect. A conventional UV treatment
device employs a traditional UV lamp, operates the UV lamp near a
skin, and irradiates the UV light to a part of the skin to be
treated.
[0004] However, the UV light causes an adverse effect such as skin
aging or cancer, in addition to the sterilization effect.
Accordingly, there is a need to provide a process for obtaining the
sterilization effect safely without any influence exerted on a
human body.
SUMMARY
[0005] Embodiments of the present disclosure provide a light
radiation device capable of obtaining a higher sterilization effect
while minimizing an adverse effect on a human body.
[0006] According to an exemplary embodiment, a light radiation
device includes a housing, a substrate provided in the housing, and
a light source mounted on the substrate. The light source includes
a first light source including at least one first light source and
configured to emit first light having a blue wavelength band, a
second light source including at least one second light source and
configured to emit second light having a ultraviolet wavelength
band, and a control unit to control light emission of the first
light source and the second light source such that the first light
and the second light are emitted, sequentially, or at times close
to each other, even if the first light is superposed with the
second light or is not superposed with the second light. A dose of
the second light source is less than 1/10 of a dose of the first
light source.
[0007] According to an exemplary embodiment, the control unit may
control the first light source and the second light source to emit
the second light after starting to emit the first light.
[0008] According to an exemplary embodiment, the second light may
correspond to at least one of UVA (ultraviolet A), UVB (ultraviolet
B), and UVC (Ultraviolet C) wavelength bands.
[0009] According to an exemplary embodiment, the first light may
have a wavelength band in a range of about 400 nm to about 500 nm.
The first light may further include light having a wavelength band
corresponding to a visible light, and the first light may have a
wavelength band in a range of about 380 nm to about 780 nm.
According to an exemplary embodiment, the second light may have a
wavelength band in a range of about 240 nm to about 280 nm.
[0010] According to an exemplary embodiment, the first light may be
irradiated for a first time, and the second light may be irradiated
for a second time shorter than the first time. According to an
exemplary embodiment, the second light may be started to be
irradiated after the first light is completely irradiated, the
second light may be started to be irradiated before the first light
is completely irradiated, and at least a portion of the first time
and the second time may have a mutually overlapping duration. In
addition, the first light may be continuously irradiated, and the
second light may be discontinuously irradiated. According to an
embodiment of the present invention, the second light may be
periodically irradiated.
[0011] According to an exemplary embodiment, the light radiation
device may be used to treat a human body. For example, the light
radiation device may be used to treat acute wound.
[0012] According to an exemplary embodiment, on the assumption that
a dose, which is in a harmless range, per day is an allowable dose
when the second light is applied to a human body, the second light
source may emit the second light within the allowable dose.
According to an exemplary embodiment, the second light may be
irradiated with a dose in a range of about 30 J/m2 to about
1,000,000 J/m2.
[0013] As described above, according to embodiments of the present
disclosure, there is provided a light radiation device capable of
obtaining a higher sterilization effect while minimizing adverse
effect on a human body.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The above and other objects and features of the present
disclosure will become apparent by describing in detail exemplary
embodiments thereof with reference to the accompanying
drawings.
[0015] FIG. 1 is a plan view illustrating a light radiation device,
according to an embodiment of the present disclosure;
[0016] FIG. 2 is a block diagram illustrating a light radiation
device, according to an embodiment of the present disclosure;
[0017] FIGS. 3A to 3C illustrate a method for driving a light
radiation device, according to an embodiment of the present
disclosure; FIG. 3A, FIG. 3B and FIG. 3C illustrate different
timings of turning on/off the first and second light sources,
respectively;
[0018] FIGS. 4A and 4B are views illustrating a method for driving
a light radiation device, according to an embodiment of the present
disclosure, when first light and second light are sequentially
irradiated; FIG. 4A illustrates irradiating the first light
followed by the sequential irradiation of the second light and FIG.
4B illustrates irradiating the second light followed by the
sequential irradiation of the first light;
[0019] FIGS. 5A to 5C illustrate a method for driving a light
radiation device, according to an embodiment of the present
disclosure; FIG. 5A illustrates one example of repeat patterns of a
first light and a second light sources; FIG. 5B illustrates another
example of repeat patterns of a first light and a second light; and
FIG. 5C illustrates further another example of repeat patterns of a
first light and a second light.
[0020] FIG. 6 is a spectrum of a light emitted from a first light
source in a light emitting device according to an embodiment of the
present disclosure;
[0021] FIG. 7A is a plan view of the light radiation device 100
according to an embodiment of the present disclosure;
[0022] FIG. 7B is a sectional view taken along line I-I' of FIG.
7A;
[0023] FIG. 8 illustrates an exploded view of a light device
according to an embodiment of the present disclosure is implemented
as a product;
[0024] FIG. 9 illustrates an assembled view of a light device
according to an embodiment of the present disclosure is implemented
as a product;
[0025] FIG. 10 is a graph illustrating and comparing a
sterilization effect depending on irradiation conditions when a
light is irradiated to a sterilization subject using a conventional
light emitting device and a light emitting device according to an
embodiment of the present disclosure;
[0026] FIG. 11A is a graph illustrating a test result of
sterilization power of first light;
[0027] FIG. 11B is a graph illustrating a test result of
sterilization power of second light;
[0028] FIG. 12A illustrates a bacteria count when first light is
individually irradiated, when second light is individually
irradiated, and when both the first light and the second light
combined are irradiated;
[0029] FIG. 12B illustrates sterilization power when first light is
individually irradiated, when second light is individually
irradiated, and when both the first light and the second light
combined are irradiated;
[0030] FIG. 13A illustrates a bacteria count irradiated with light
obtained by differently setting the sequence of combining first
light and second light;
[0031] FIG. 13B illustrates sterilization power obtained by
differently setting the sequence of combining the first light and
the second light;
[0032] FIG. 14A illustrates a bacteria count as a function of an
amount of the first light under in vitro condition when first light
and second light were sequentially irradiated;
[0033] FIG. 14B illustrates sterilization power as a function of
the amount of the first light under in vitro condition when the
first light and the second light were sequentially;
[0034] FIG. 15A illustrates a bacteria count as a function of an
amount of the first light under in vivo condition, when first light
and second light were sequentially irradiated;
[0035] FIG. 15B illustrates the sterilization power as a function
of an amount of the first light under in vivo condition, when the
first light and the second light were sequentially irradiated;
[0036] FIG. 16 is a graph illustrating the variation in
sterilization power based on days under in vivo condition;
[0037] FIG. 17 is a graph illustrating the measurement result of
the number of the bacteria based on days under in vivo
condition;
[0038] FIG. 18 is a graph illustrating the variation in an area of
a wound based on days under in vivo condition;
[0039] FIGS. 19A and 19B are photographs obtained by capturing
images of the shape of the wound area based on days, in which FIG.
19A is a photograph of wounds in a non-irradiation group, and FIG.
19B is a photograph of wounds in the light irradiation group;
[0040] FIG. 20A is a graph illustrating the percentage of a thymine
dimer in a tissue; and
[0041] FIG. 20B illustrates a light emission degree of a part
stained with DCFH-DA.
DETAILED DESCRIPTION OF EMBODIMENTS
[0042] While the invention is susceptible to various modifications
and alternative forms, specific embodiments thereof are shown by
way of example in the drawings and will be described herein in
detail. It should be understood, however, that there is no intent
to limit the invention to the particular forms disclosed, but on
the contrary, the invention is to cover all modifications,
equivalents, and alternatives falling within the spirit and scope
of the invention.
[0043] Hereinafter, exemplary embodiments of the present disclosure
will be described in more detail with reference to accompanying
drawings.
[0044] The present disclosure relates to a light radiation device
capable of sterilizing a target by applying a sterilizing light to
the target. In particular, according to an embodiment of the
present disclosure, the light radiation device may be used to treat
a wound. When a target to be sterilized is a human body and the
skin of the human body is wounded, it is necessary to sterilize a
pathogen at the wounded part. A sterilizing device according to one
embodiment of the present disclosure may be used to sterilize the
pathogen in the wound. In this case, the pathogens refer to
microorganisms such as bacteria, viruses, germs, fungi, protists,
or moulds. According to embodiments of the present disclosure, the
light radiation device may be used for various wounds such as a
wound, an ulcer, surgical site infection, a laceration, an incised
wound, or a punctured wound.
[0045] FIG. 1 is a plan view illustrating a light radiation device,
according to an embodiment of the present disclosure.
[0046] According to embodiments of the present disclosure, a light
radiation device 100 includes a first light source 30 to emit first
light, a second light source 40 to emit second light, and a
substrate 20 to mount the first and second light sources 30 and 40
thereon.
[0047] Since the first light source 30 and the second light source
40 are mounted on the substrate 20, the substrate 20 is not limited
to a specific form and may be provided in various forms sufficient
to mount the first and second light sources 30 and 40 thereon. The
substrate 20 may be provided in the form of including a wiring to
supply power to the first and second light sources 30 and 40. In
some embodiments, the substrate 20 may include, for example, a
metallic substrate or a printed circuit board including the
wiring.
[0048] The first light source 30 may emit first light in a blue
wavelength band of a visible light wavelength band. The first light
may correspond to light in a wavelength band of about 400 nm to
about 500 nm. In some embodiments of the present disclosure, the
first light may have a wavelength band of about 400 nm to about 420
nm. More specifically, the first light may have a wavelength of 405
nm.
[0049] The first light acts on a photosensitizer present in
microorganisms such as bacteria, germs, and moulds to damage the
cell, thereby result in the death of the microorganisms. The first
light corresponds to the absorption wavelength of porphyrin, which
is a photosensitizer present in bacteria. The first light exhibits
higher sterilization power, particularly, in the wavelength range
of 400 nm to 420 nm. Additionally, the first light may be in the
wavelength range of 455 nm to 470 nm, which corresponds to the
absorption wavelength band of the porphyrin. The porphyrin is a
pigment that is essential for the process of intracellular oxygen
transfer. The porphyrin exhibits a higher absorption, particularly,
in the wavelength range of about 402 nm to about 420 nm, and more
particularly absorbs a wavelength in the range of about 455 nm to
470 nm. In an embodiment of the present disclosure, since the
content of the porphyrin varies depending on the type of bacteria,
the porphyrin may be used for destroying specific bacteria by
adjusting the wavelength and the intensity of the first light. When
the first light is applied to bacteria, the porphyrin in the
bacteria absorbs the first light, and reactive oxygen species are
produced in the cell of the bacteria due to the energy of the first
light. The reactive oxygen species are accumulated in cells of the
bacteria to oxidize cell walls of the bacteria, thereby destroying
the bacteria.
[0050] The second light source 40 emits the second light in the UV
wavelength band. In other words, the second light may be light
having a wavelength band in the range of about 100 nm to about 400
nm, and may be UVA, UVB, or UVC. The UVA may have a wavelength band
in the range of about 315 nm to about 400 nm, the UVB may have a
wavelength band in the range of about 280 nm to about 315 nm, and
the UVC may have a wavelength band in the range of about 100 nm to
about 280 nm. In some embodiments of the present disclosure, the
second light may correspond to the UVC, and may have a wavelength
band in the range of about 240 nm to about 280 nm. More
specifically, the second light may have the wavelength of 275
nm.
[0051] When the second light is applied to bacteria, the DNA in the
bacteria absorbs the second light, and the DNA structure may be
changed due to the energy of the second light. The absorption of
light by the DNA causes the binding of thymine and adenine in the
DNA to be broken. This is because a base such as purine or
pyrimidine, which constitutes the DNA, strongly absorbs UV light.
As a result of light absorption, a thymine dimer is formed. This
process leads to the DNA mutation, and the mutated DNA causes the
death of the bacteria since the mutated DNA has no ability of cell
proliferation. The DNA may absorb light having a wavelength band in
the range of about 240 nm to about 280 nm.
[0052] FIG. 2 is a block diagram illustrating the light radiation
device, according to an embodiment of the present disclosure.
[0053] Referring to FIG. 2, according to embodiments of the present
disclosure, the light radiation device 100 may include the first
light source 30 to emit first light, the second light source 40 to
emit second light, a control unit 50 to control the first light
source 30 and the second light source 40, and a power supply unit
60 to supply power to the control unit 50 and the first and second
light sources 30 and 40.
[0054] Each of the first and second light sources 30 and 40 may
emit the first light including a blue wavelength band and the
second light including a UV wavelength band, as described above.
The first and second light sources 30 and 40 may be implemented
with various types of light sources. For example, each of the first
and second light sources 30 and 40 may independently use various
types of light sources such as a light emitting diode, a halogen
lamp, a fluorescent lamp, a gas discharge lamp, or a laser, and the
types of the light sources are not limited.
[0055] The control unit 50 may control whether light is emitted
from the first and second light sources 30 and 40, an amount of the
light, the intensity of the light, or a time in which the light is
emitted, such as a timing, a duration, etc. Additionally, or
alternatively, the control unit 50 may control whether the light is
emitted, an amount of the light, the intensity of the light, or the
time in which the light is emitted, through various manners.
[0056] The power supply unit 60 is electrically connected with the
first and second light sources 30 and 40 and the control unit 50 to
supply power to the first and second light sources 30 and 40 and
the control unit 50. Although the drawings illustrate that the
power supply unit 60 supplies power to the first and second light
sources 30 and 40 via the control unit 50, the present disclosure
is not limited thereto. In other embodiments, the power supply unit
60 may be directly connected with the first and second light
sources 30 and 40 to supply power.
[0057] The light radiation device 100 may further include an
optical unit (not shown) to selectively collect or radiate light
emitted from the first and second light sources 30 and 40. The
optical unit may focus the light generated from the first and
second light sources 30 and 40 to a small area, or a large area as
necessary. Alternatively, the light may be focused or dispersed in
a uniform or non-uniform depending on a position where the light is
irradiated. The optical unit may include at least one lens, and the
lens may perform various functions of focusing, dispersing,
homogenizing, or non-homogenizing light from the first and second
light sources 30 and 40.
[0058] For example, when a light is irradiated in the small area
using the light emitting device 100, a lens for focusing the light
from the first and second light sources 30 and 40 may be used. On
the contrary, when a light is provided in the large area, for
example, an entire room using the light emitting device 100
according to an exemplary embodiment, a lens for dispersing the
light may be used.
[0059] In the present embodiment, the control unit 50
simultaneously, or individually drives the first light source 30
and the second light source 40. In other words, the first and
second light sources 30 and 40 may be turned on/off simultaneously,
or individually. In addition, even the intensities of light, that
is, the first light and the second light emitted from the first and
second light sources 30 and 40 may be simultaneously, or
individually controlled.
[0060] In an embodiment of the present disclosure, the control unit
50 may allow a daily irradiation amount to be 3 mJ/cm.sup.2 or
less. In particular, in the case of UVC, the control unit 50
maintains the daily irradiation amount to be 3 mJ/cm.sup.2 or less.
Further, in the case of UVA, when a daily irradiation time is less
than 1,000 seconds, the daily irradiation amount is maintained such
that the daily irradiation amount does not exceed 1 J/cm.sup.2, and
when the daily irradiation time is equal to or greater than 1,000
seconds, the daily irradiation amount is maintained such that the
daily irradiation amount does not exceed 1 mW/cm.sup.2.
[0061] In an embodiment of the present disclosure, the distance
from the first and second light sources 30 and 40 to a target to be
sterilized may be variously set. For example, the distance may vary
depending on the intensities of light from the first and second
light sources 30 and 40, the type of the target to be sterilized,
an area or a volume to be sterilized, or a target material (for
example, germs or bacteria) to be sterilized. Similarly, in an
embodiment of the present disclosure, the time in which light from
the first light source 30 and the second light source 40 is
irradiated may be variously set.
[0062] FIGS. 3A to 3C illustrate a method for driving a light
radiation device, according to some embodiments of the present
disclosure, and illustrates various timing based on turning on/off
the first and second light sources;
[0063] In some embodiments, in the light radiation device 100, the
first light from the first light source 30 is designated as "L",
the second light from the second light source 40 is designated as
"L2", and an elapsed time is designated as "T". The first light
source 30 is turned on for a first time t1 to emit the first light
L1, and the second light source 40 is turned on for a second time
t2 to emit the second light L2. In some embodiments, the first time
t1 in which the first light L1 is irradiated may be longer than the
second time t2 in which the second light L2 is irradiated. Since
the second light L2 exerts a great influence on, especially, a
human body, the second light L2 may be irradiated for a shorter
time than the irradiation time of the first light L. For example,
the first light L1 may be applied for about 10 minutes, and the
second light L2 may be applied for less than about 10 seconds.
[0064] The irradiation times t1 and t2 of the first light L1 and
the second light L2 emitted from the first and second light sources
30 and 40, and amounts of the first light L1 and the second light
L1 in irradiation may vary, but a total dose applied to the target
to be sterilized may be set to a threshold value harmless to the
human body. In particular, a predetermined dose per day, which is
in a harmless range, may be an allowable dose when the second light
L2 is applied to the human body, and then the second light source
40 may emit the second light L2 less than the allowable dose. The
dose may vary depending on the harmfulness of the light emitted
from the first light source 30 and the second light source 40. In
some embodiments, the dose of the second light source 40 may be
less than 1/10 of the dose of the first light source 30. In other
embodiments, the dose of the second light source 40 may be 1/20 of
the dose of the first light source 30. For example, the allowable
dose of the second light L2 may be in the range of about 30
J/m.sup.2 to about 1,000,000 J/m.sup.2.
[0065] As illustrated in FIG. 3A and FIG. 3C, the first light L1
and the second light L2 may start to be irradiated simultaneously,
or at mutually different times. When the first light L1 and the
second light L2 may start to be irradiated at mutually different
times, the first light L1 may be first irradiated, or
alternatively, the second light L2 may be first irradiated. The
times in which the first light L1 and the second light L2 are
irradiated may overlap, or may not overlap. When the times, in
which the first light L1 and the second light L2 are irradiated, do
not overlap, the interval between the times in which the first
light L1 and the second light L2 are applied may be set to be a
shorter time interval. For example, the interval between the times
in which the first light L1 and the second light L2 are applied may
be within several hours, several minutes, or several seconds.
[0066] The sterilizing device according to some embodiments of the
present disclosure exhibits a sterilization effect higher than the
individual sterilization effect by the first light L1 or the
individual sterilization effect by the second light L2, due to the
synergy effect that may be obtained as the first light and the
second light are applied simultaneously, or within the times close
to each other.
[0067] In some embodiments, the sterilizing device employs the
sterilization principle of the first light of generating reactive
oxygen species due to a photosensitizer and the second light of
causing the damage to DNA by obtaining a thymine dimer. In some
embodiments, the significantly high sterilization effect may be
obtained within a shorter time even with a smaller amount of energy
by using both the first light source and the second light source,
as compared to the case of an individual use of the first and
second light sources.
[0068] The death rate of the bacteria having received chemical and
physical stresses may rapidly increase even due to a weak stimulus
additionally applied thereto. Accordingly, in some embodiments,
mutually different two sterilizing mechanisms based on the first
light and the second light, which correspond to blue light and UV
light, apply mutually different stresses to the bacteria.
Accordingly, the synergy effect of the stresses may destroy the
bacteria with a smaller amount of energy as compared to the
individual use of the two light sources. In some embodiments, the
second light is irradiated in the amount harmless to a biological
tissue of the target, which is to be sterilized, while being
applied together with the first light. Accordingly, the
sterilization synergy effect may be obtained by two light sources,
so the present disclosure may produce the effective sterilization
effect within a shorter time without the damage to a human tissue,
when the target to be sterilized is a human body.
[0069] To the contrary, the use of only the first light is not
harmful to the human body, but the sterilization power may be weak.
Accordingly, the first light needs to be irradiated with higher
energy for a longer time. The use of only the second light produces
excellent sterilization power, but it may be harmful to the human
body.
[0070] As described above, in some embodiments of the present
disclosure, the sterilizing device may be used to sterilize various
pathogens. Particularly, the light radiation device 100 may be used
for sterilizing infectious bacteria in the initial stage by
irradiating sterilizing light to an acute infected wound, and thus,
the period for curing the wound may be short. For the acute wound,
reducing an infectious bacteria count in the initial stage of the
wound is the most important in the curing process of the acute
wound. When the initial sterilization is not sufficiently performed
with respect to the acute wound, the curing of the cut may not be
fully perform. A cut may develop into a chronic cut that may not
cured for 3 months or longer. However, when the infectious bacteria
are sterilized in the initial stage using the light radiation
device 100, the chronic cut may be prevented.
[0071] In addition, microorganisms, such as bacteria, germs, and
moulds, present on animals and various articles may be sterilized
in addition to the human body. Accordingly, the target to be
sterilized by the sterilizing device according to an embodiment of
the present disclosure is not limited to a human body, but it may
apply to animals and various articles.
[0072] According to some embodiments of the present disclosure, as
described above, the sterilization effect may significantly
increase when both the first light and the second light emitted
from the first light source 30 and the second light source 40 are
applied simultaneously, or within the times close to each other. In
addition, in some embodiments, when the first light and the second
light are sequentially irradiated in that order, the significantly
higher sterilization effect may be obtained as compared to the
order that the second light and the first light are sequentially
irradiated. Accordingly, the sterilization effect may be maximized
through sequentially applying the first light, and then the second
light to the target to be sterilized.
[0073] According to some embodiments of the present disclosure, the
first light is applied to the target to be sterilized for a
specific time before the second light is irradiated, and then the
second light is irradiated. Accordingly, DNA is prevented from
being recovered from the damage again after the first light is
first irradiated. Accordingly, the significantly higher
sterilization effect may be obtained even with a smaller dose as
compared to the case that the first light is individually
irradiated, i.e., without the irradiation of the second light. In
addition, the second light may have excellent sterilization power
for the subject to be sterilized but it may have an adverse effect
on the human body, for example, skin aging or cancer, when the
human body is exposed to the second light for a long time.
Therefore, there may be limitations as to applying only the second
light to the subject to be sterilized. However, according to
embodiments of the present disclosure, the irradiation of the
second light in addition to the irradiation of the first light may
obtain the significant sterilization effect despite a small amount
of the irradiation of the second light, in comparison with the
irradiation of the second light alone.
[0074] In an embodiment of the present disclosure, when the second
light is emitted sequentially after the first light, in addition to
the first light, an amount of the second light needs to be
controlled. In some embodiments, the synergy effect of
sterilization may be obtained and an influence on the human body
may be minimized by sequentially irradiating the first light and
the second light. To this end, when the first light source 30 and
the second light source 40 are turned on/off, one or more manner of
continuously emitting light, one or more manner of sequentially
increasing or decreasing the intensity of light, one or more
flickering manner, or a manner of combining the above manners may
be employed.
[0075] FIGS. 4A and 4B are views illustrating a method for driving
the light radiation device according to embodiments of the present
disclosure, when the first light and the second light are
sequentially irradiated, and illustrates different times associated
with turning on/off the first and the second light sources. The
different times here may include different timings of emitting the
first and second light sources, different durations of the
irradiation of the first and the second light sources, etc.
[0076] Referring to FIGS. 4A and 4B, the first light L1 may be
first irradiated, and then the second light L2 may be irradiated.
When the first light L1 is first irradiated and then the second
light L2 is irradiated, the sterilization effect may significantly
increase as compared to the case that the second light is first
irradiated and then the first light L1 is irradiated. When the
second light L2 is first irradiated and the first light L1 is later
irradiated, the effect of inhibiting the proliferation of bacteria
by the second light L2 may be reduced. For example, even if the
structure of DNA is partially mutated by the second light L2, the
mutated DNA may be subject to photoreactivation by irradiating the
first light L. The bacteria recovered through the irradiation of
the first light L1 return to a state in which the bacteria may be
proliferated. Accordingly, although the total sterilization power
is still excellent, the sterilization power in the final stage may
be more reduced as compared to the case that the first light L1 and
the second light L2 are sequentially irradiated.
[0077] Alternatively, when the first light L1 is applied to the
target to be sterilized and then the second light L2 is
sequentially applied to the target to be sterilized by using the
light radiation device 100, reactive oxygen species are generated
in bacteria by the first light L1, which is first irradiated, so
oxidative stress is caused in bacteria. In this state, since
additional sterilization is performed by the second light L2
irradiated later, the death rate of the bacteria may significantly
increase even in a smaller irradiation amount.
[0078] In some embodiments, the time point at which the second
light L2 is applied may vary in the setting that the first light L1
and the second light L2 are sequentially applied. For example,
irradiation of the second light L2 may start after the irradiation
of the first light L1 is finished as illustrated in FIG. 3A, and as
illustrated in FIG. 3B, the irradiation of the second light L2 may
start even though the irradiation of the first light L1 is not
finished. In this case, since time points at which the first light
L1 and the second light L2 are irradiated may partially overlap,
the first time and the second time may have mutually overlap
durations.
[0079] As described above, the light radiation device 100 according
to embodiments of the present disclosure may be driven by the
control unit 50 in the setting that the first light L1 and the
second light L2 are sequentially irradiated.
[0080] FIGS. 5A to 5C illustrate a method for driving a light
radiation device, according to embodiments of the present
disclosure, and illustrates different times associated with turning
on/off the first and second light sources;
[0081] Referring to FIG. 5A, the first light L1 and the second
light L2 may be periodically irradiated to the target to be
sterilized. In other words, the first light L1 is irradiated to the
target to be sterilized for the first time t1, and the second light
L2 is irradiated to the target to be sterilized for the second time
t2. Then, irradiation of the first light L1 and the second light L2
is repeated. The pattern of the repeat period and the repeat count
may vary depending on the type of the target to be sterilized and
the total amount of the target to be sterilized. In this case, the
repeat period and the repeat count of the first light L1 and the
second light L2 may be determined such that the total dose of the
first light L1 and the total dose of the second light L2 become
values equal to or less than the allowable dose for the human body
in order to avoid harmful effects.
[0082] Referring to FIG. 5B, when the first light L1 and the second
light L2 are applied, the first light L1 may be continuously
applied to the target to be sterilized without interruption under
the condition that the second light L2 is applied after the first
light L1 is applied. To the contrary, the second light L2 is not
continuously applied, but applied at intervals, and upon
application, the second light L2 is superposed with the first light
L1.
[0083] As illustrated in FIGS. 5A and 5B, the first light L1 may be
continuously applied to the target to be sterilized for the first
time t1 without interruption, and the second light L2 may be
applied to the target to be sterilized for the second time t2
during the continuous application of the first light L1, after the
first light L1 is applied to some extent. The second light L2 may
be continuously repeatedly applied to the target to be
sterilized.
[0084] Referring to FIG. 5C, when the first light L1 and the second
light L2 are applied, the first light L1 may be continuously
applied to the target to be sterilized without interruption or may
be stopped before the second light L2 is applied, under the
condition that the second light L2 is applied after the first light
L1 is applied. As illustrated in FIG. 5C, when the first light L1
is applied to the target to be sterilized for the first time t1,
the second light L2 may be applied for the second time t2 during
the application of the first light L. Thereafter, after the
application of the first light L1 is finished, the second light L2
may be applied for a third time t3. In this case, regarding the
application time of the second light L2, the second light L2 may be
applied to the target to be sterilized for mutually different times
within an allowable dose permitted as being safe for a human body.
In other words, the second time t2 and the third time t3 in which
the second light L2 is applied may have mutually different values,
as shown in FIG. 5C.
[0085] In some embodiments of the present disclosure, when the
second light L2 is applied as soon as the first light L1 is applied
and stopped, the highest sterilization effect may be exhibited, and
the second light L2 may be sequentially applied without
interruption in the state the first light L1 is applied. However,
instead of that the second light L2 is applied as soon as the first
light L1 is applied and stopped, time may be slightly elapsed after
the first light L1 is applied and stopped and then the second light
L2 may be applied. In this case, the elapsed time interval may be
significantly short. Meanwhile, when the sterilization effect is
obtained as the first light L1 and the second light L2 are
sequentially applied, the next sequential irradiation of the first
light L1 and the second light L2 may be performed after a
sufficient amount of time is elapsed.
[0086] In embodiments of the present disclosure, the first light
source includes a blue wavelength sterilizable in the visible light
wavelength band, but the first light source is not limited thereto.
In other embodiments, the first light source may further include
another light of the visible light wavelength band in addition to
the blue wavelength band.
[0087] FIG. 6 is a spectrum of a light emitted from a first light
source in a light emitting device according to embodiments of the
present disclosure.
[0088] Referring to FIG. 6, the first light source emits the light
in a wavelength band of about 380 nm to about 750 nm, most of which
corresponds to a visible light wavelength band. That is, the first
light source corresponds to a light source which emits white light.
In sine embodiments, the first light source includes a light in the
blue wavelength band which is combined with the second light to
generate synergy, and thus the above-described sterilization effect
may be obtained in the same manner.
[0089] In addition, the first light source in the embodiment has a
spectrum similar to sunlight having a form in which lights of the
entire wavelength bands are evenly mixed. However, the first light
source according to embodiments of the present disclosure is
different from sunlight because the first light source emits a
light except for the most of an ultraviolet wavelength band. The
light source according to embodiments of the present disclosure
emits a light having a wavelength band of about 380 nm to about 780
nm which substantially correspond to the entire wavelength band of
a visible light.
[0090] In embodiments of the present disclosure, the phrase,
"similar to sunlight" means that an overlapping area based on a
normalized solar spectrum is more than a specific value and a
deviation of the peak from the normalized solar spectrum (a
deviation degree from the peak of the normalized solar spectrum) is
lower than a specific value. For example, in an embodiment of the
invention, the first light source may emit the light having an area
of about 55% or more of an area of the normalized solar spectrum
and a peak of the first light may have a deviation of about 0.14 or
less from the normalized solar spectrum.
[0091] As described above, because the first light may have the
spectrum similar to the sunlight, the first light may have an
effect similar to an effect of frequent exposure to the sunlight.
Therefore, synthesis of vitamin D may be facilitated or prevalence
of diseases such as myopia may be lowered.
[0092] According to embodiments of the present disclosure, the
light radiation device 100 may be implemented in various forms.
FIG. 7A is a plan view of the light radiation device 100 according
to embodiments of the present disclosure, and FIG. 7B is a
sectional view taken along line I-I' of FIG. 7A.
[0093] Referring to FIGS. 7A and 7B, the light radiation device 100
may include the first light source 30, the second light source 40,
and the substrate 20 on which the first light source 30 and the
second light source 40 are mounted.
[0094] In some embodiments, a plurality of first light sources 30
may be provided, and a plurality of second light sources 40 may be
provided. For example, the first light sources 30 and the second
light sources 40 may be provided in equal numbers and may be
alternately arranged in the form of a matrix as illustrated in FIG.
7A. However, numbers of the first and second light sources 30 and
40 is not limited thereto, and the number of the first light
sources 30 may be smaller than the number of the second light
sources 40. In addition, according to embodiments of the present
disclosure, the first light sources 30 and the second light sources
40 may be regularly or irregularly arranged depending on the number
of the first light sources 30 and the number of the second light
sources 40.
[0095] According to embodiments of the present disclosure, the
light radiation device 100 may further include a housing (not
shown) to receive the first and second light sources 30 and 40 and
the substrate 20. The housing may have a transmission window to
transmit light emitted from the first and second light sources 30
and 40 and the light emitted from the first and second light
sources 30 and 40 may be provided to the human body through the
transmission window.
[0096] In an embodiment of the present disclosure, the control unit
50 (see FIG. 2) may be provided in various forms on the substrate
20. For example, the control unit 50 may be provided in the form of
a separate circuit wiring or in the form of a separate chip, to be
mounted on the substrate 20.
[0097] As described above, according to an embodiment of the
present disclosure, the sterilizing device may be applied to
various other devices requiring sterilizing, and particularly, may
be applied to a device using a light source. In addition, the
sterilizing device may be used as a lighting device in addition to
the intrinsic function thereof (i.e., the sterilizing function).
For example, according to an embodiment of the present disclosure,
the sterilizing device may further include an additional light
source for lighting a specific space. In this case, the additional
light source may emit light in a visible wavelength band. The
additional light source may emit light corresponding to the entire
spectrum of the visible light area, or may emit light corresponding
to the spectrum of a specific color.
[0098] Alternatively, in an embodiment of the present disclosure,
the first light source 30 may emit light in the visible light
wavelength band including light in the blue wavelength band without
an additional light source. For example, the first light source 30
emits light in a wavelength band in the range of about 380 nm to
about 750 nm, and most of the light corresponds to a visible light
wavelength band. In this case, the first light source 30 may
totally provide light in the visible light wavelength band while
providing light in the blue wavelength band for obtaining a synergy
effect through the combination with the second light source 40,
thereby obtaining the sterilization effect as in embodiments
described above. In this manner, when an additional light source is
provided to emit light in the visible light wavelength band, or the
first light source emits the light in the visible light wavelength
band, the light may have the spectrum similar to that of sunlight.
The light having the spectrum similar to that of sunlight may
exhibit the effect similar to being frequently exposed to sunlight.
Accordingly, the synthesis of vitamin D may be facilitated or the
prevalence ratio of illnesses such as nearsightedness may be
lowered.
[0099] Hereinafter, a specific embodiment of a lighting device
according to an embodiment of the present disclosure will be
described.
[0100] FIGS. 8 and 9 illustrate an example in which a light device
according to an embodiment of the present disclosure is implemented
as a product.
[0101] Referring to FIG. 8, a lighting device according to an
embodiment of the present disclosure includes the light emitting
device 100 for emitting a light, a housing 300 in which the light
emitting device 100 is accommodated, a window 210 provided at an
upper part of the light emitting device, and a fixer 220 fixing the
window 210 and the housing 300.
[0102] The housing 300 accommodates and supports the light emitting
device 100 and is not limited as long as the housing 300 supplies
electrical power to the light emitting device 100. For example, as
shown, the housing 300 may include a main body 310, a power
supplier 320, a power case 330, and a power connector 340. The
power supplier 320 may be accommodated in the power case 330 and
electrically connected to the light emitting device 100 and may
include at least one IC chip. The IC chip may adjust, convert or
control characteristics of the power supplied to the light emitting
device 100.
[0103] The power case 330 may accommodate and support the power
supplier 320, and the power case 330 in which the power supplier
320 is fixed may be located inside the main body 310.
[0104] The power connector 340 may be disposed at a lower end of
the power case 330 and may be coupled with the power case 330.
Accordingly, the power connector 340 may be electrically connected
to the power supplier 320 inside the power case 330 to serve as a
path through which external power is supplied to the power supplier
320.
[0105] The light emitting device 100 may include the substrate 20
and the first and second light sources 30 and 40 disposed on the
substrate 20 and may have a form as the above-described
embodiments. The light emitting device 100 may be provided on the
upper part of the main body 310 and electrically connected to the
power supplier 320. The substrate 20 may have a shape corresponding
to the fixer 220 of the upper part of the main body 310 to be
stably fixed to the main body 310.
[0106] The window 210 may be disposed on the housing 300 to cover
the upper part of the light emitting device 100. The window 210 may
be disposed on the light emitting device 100 and may be fixed to
the main body 310 to cover the light emitting device 100. The
window 210 may be provided with a lens member 211 to facilitate
diffusion of the light from the light emitting device 100. The
window 210 may have a transparent material. A shape and light
transmittance of the window 210 may be modified to adjust
directivity of the lighting device. Therefore, the window 210 may
be modified in various forms depending on the purpose of use and
application of the lighting device.
[0107] The fixer 220 may be provided on the window 210 to fasten
the window 210, the light emitting device 100, and the main body
310 to one another.
[0108] The lighting device having the above-described structure may
be mounted in various light treatment devices. In addition, the
lighting device may be used as a lighting fixture mounted on a wall
or a ceiling forming a specific space (e.g., a chamber).
[0109] The lighting device according to an embodiment of the
present disclosure may be implemented in a form which is used in
real life.
[0110] Referring to FIG. 9, the lighting apparatus according to
another embodiment of the present disclosure may include a pedestal
530, the light emitting device 100 for emitting the light, a
supporter 520, and a reflector 400 surrounding the light emitting
device 100. The lighting device 1000' according to another
embodiment of the present disclosure may be disposed on a variety
of treatment devices.
[0111] An input unit 530 may be disposed on a surface of the
pedestal 510 to control an operation of the lighting device 1000'.
The pedestal 510 is connected and fixed through the substrate 20 on
which the lighting device 100 is disposed and the supporter 520.
The pedestal 510 allows power to be supplied to the light emitting
device through a power supplier 600. The supporter 520 may be
connected between the pedestal 510 and the substrate 20 on which
the light emitting device 100 is disposed and a wire (not shown)
for supplying the power may be provided therein.
[0112] In the embodiment, the supporter 520 is shown as being
formed of a single solid material, but is not limited thereto, and
may be made of a bendable material capable of bending at least one
time or made of a flexible material to be changed into various
shapes. For example, the supporter 520 may have a ductility to be
deformed by a specific degree of external force and maintain a
shape the supporter 520 when there is no external force. For
example, a wiring may receive an external force to be partially
changed and the changed wiring 130 may maintain the final shape to
which the external force is applied when the external force is
removed. To this end, the supporter 520 may be provided in a
bellows shape.
[0113] The reflector 400 surrounding the light emitting device 100
may be made of a metallic material such as aluminum or the like,
which is capable of reflecting a light emitted from the light
emitting device and increasing illuminance, or a material capable
of transmitting a light. A coating layer including a photocatalyst
material may be formed on an inner surface of the reflector 400.
The photocatalyst material may include at least one selected from
the group of TiO.sub.2, ZnO, ZrO.sub.2, and WO.sub.3.
[0114] Hereinafter, an experimental example of the sterilization
effect of the light radiation device according to an embodiment of
the present disclosure will be described.
Experimental Example 1--Sterilization Effect According to
Irradiation Conditions
[0115] FIG. 10 is a graph illustrating a sterilization effect
depending on irradiation conditions when a light is irradiated to a
sterilization subject using a conventional light emitting device
and a light emitting device according to an embodiment of the
present disclosure. In FIG. 10, a bacterium used as a subject of
sterilization is Staphylococcus aureus. The Staphylococcus aureus
was smeared on a bacterial culture medium and incubated at 35 to
37.degree. C. for one day, and bacterial colonies formed on the
bacterial culture medium were collected, suspended in a saline
solution, and performed with centrifuge, and a supernatant was
discarded, a saline solution is added to be diluted, and thus a
bacterial solution having a suitable concentration for a
sterilization experiment was prepared. The prepared bacterial
solution was placed in separate containers, the conventional light
emitting device and the light emitting device according to an
embodiment of the present disclosure were installed at a specific
distance from the containers, and then lights were sequentially
irradiated. Thereafter, the bacterial solutions irradiated with the
lights were diluted, applied evenly bacterial culture media, and
incubated for one day at 35 to 37.degree. C. Colonies formed on the
bacterial culture media were checked, multiplied by a dilution
factor, and counted. Therefore, the results for sterilization
effects were obtained.
[0116] In FIG. 10, an x-axis shows doses of the first and second
lights and a y-axis shows degree of inactivation of bacteria on a
logarithmic scale. In Comparative Example 1, only the second light
of 275 nm wavelength band was applied to the bacteria. In
Comparative Example 2, only the first light of 405 nm wavelength
band was applied to the bacteria. In Comparative Example 3, the
first light of the 405 nm wavelength band was applied to the
bacteria after the second light of the 275 nm wavelength band. In
Example, the second light of the 275 nm wavelength band was applied
to the bacteria after the first light of the 405 nm wavelength band
was applied. Meanwhile, in the graph, in Comparative Example 1, the
second light of the wavelength band of 275 nm was applied only with
a dose of 3 mJ/cm.sup.2, and in Comparative Example 2, Comparative
Example 3, and Example, respectively, the first light of the
wavelength band of 405 nm was applied and changed at doses of 30
mJ/cm.sup.2, 60 mJ/cm.sup.2, 90 mJ/cm.sup.2, 120 mJ/cm.sup.2, and
150 mJ/cm.sup.2, respectively and the second light of the
wavelength band of 275 nm was applied with a dose of 30
mJ/cm.sup.2. Here, in the case of the second light, the dose is set
lower than that of the first light in consideration of the
allowable dose to the human body.
[0117] Referring to FIG. 10, when only the second light was applied
to the bacteria at a dose of 3 mJ/cm.sup.2 in Comparative Example
1, the degree of inactivation was about 1.5 log CFU/ml. When only
the first light was applied to the bacteria at a dose of 30
mJ/cm.sup.2 in Comparative Example 2, the degree of inactivation
was about 1 log CFU/ml. When the second light was pre-irradiated
with the bacteria at a dose of 3 mJ/cm.sup.2 and the first light
was post-irradiated with a dose of 30 mJ/cm.sup.2, the degree of
inactivation was about 1.5 log CFU/ml. However, in the embodiment
in which the first light was irradiated with a dose of 30
mJ/cm.sup.2 and the second light was irradiated with a dose of 3
mJ/cm.sup.2, the deactivation degree was about 4 log CFU/ml and the
sterilization effect was very high. Here, in Comparative Example 3
and Example, the order of irradiation of the first light and the
second light were different but the same dose was irradiated to the
bacteria. It was seen that the actual sterilization degree showed a
significant difference in effect.
[0118] In addition, in Comparative Example 2, Comparative Example
3, and Example, the first light of a dose of 60 mJ/cm.sup.2 were
applied. The sterilization effect of Example was significantly
higher than Comparative Example 2, or Comparative Example 3.
[0119] Meanwhile, when the dose of the first light was more than 90
J/cm.sup.2, Comparative Example 3 and Example showed a stagnant
value of about 6 log CFU/ml. This is because there are no more
bacteria to be sterilized under laboratory conditions without
introduction of new bacteria. Accordingly, it may be expected that
the sterilization effect of Example will be significantly higher
than the sterilization effect of Comparative Examples 1 to 3 under
open external conditions in which new bacteria are continuously
introduced.
[0120] Table 1 below shows a minimum dose in order to obtain a
desired degree of sterilization in Comparative Examples 1 to 3 and
Example. Here, in Comparative Example 1, only the second light of
275 nm wavelength band was applied to the bacteria. In Comparative
Example 2, only the first light of 405 nm wavelength band was
applied to the bacteria. In Comparative Example 3, the first light
of the 405 nm wavelength band was applied to the bacteria after the
second light of the 275 nm wavelength band. In Example, the second
light of the 275 nm wavelength band was applied to the bacteria
after the first light of the 405 nm wavelength band was
applied.
[0121] Referring to Table 1, in the case of Comparative Example 1
using the second light source alone, a sterilization effect of 90%
or more, 99% or more, or 99.9% or more even might be obtained with
a very small dose. However, since the influence on the human body
is large in the case of the second light, it is difficult to
proceed with sterilization by only raising a dose of the second
light.
[0122] Next, in Comparative Example 2, Comparative Example 3 and
Example using a combination of the first light and the second
light, it was seen that Example had higher sterilization effect
with a very small dose of the first light in comparison with those
of Comparative Example 2 and Comparative Example 3. For example, in
order to obtain a sterilization effect of 99%, a dose of 65
J/cm.sup.2 was required for Comparative Example 2 and a dose of 40
J/cm.sup.2 was required for Comparative Example 3, whereas only a
dose of 15 J/cm2 was required for Example.
TABLE-US-00001 TABLE 1 Sterilization Comparative Comparative
Comparative performance Example Example 1 Example 2 Example 3 1 log
sterilization 7 J/cm.sup.2 .+-. 10% 2 mJ/cm.sup.2 .+-. 10% 30
J/cm.sup.2 .+-. 10% 20 J/cm.sup.2 .+-. 10% (90% sterilization) 2
log sterilization 15 J/cm.sup.2 .+-. 10% 4 mJ/cm.sup.2 .+-. 10% 65
J/cm.sup.2 .+-. 10% 40 J/cm.sup.2 .+-. 10% (99% sterilization) 3
log sterilization 25 J/cm.sup.2 .+-. 10% 8 mJ/cm.sup.2 .+-. 10% 110
J/cm.sup.2 .+-. 10% 60 J/cm.sup.2 .+-. 10% (99.9%
sterilization)
[0123] As described above, it was seen that the light emitting
device according to the embodiments of the present disclosure
exhibited a significantly higher sterilization effect than the
conventional light emitting device such as Comparative Example 1,
Example 2, and Example 3.
Experimental Example 2--Individual Sterilization Power Test of the
First Light and the Second Light
[0124] In the present test, an MRSA strain was used as a pathogen.
After the MRSA strain was cultured, a suspension having a constant
bacteria concentration (7 log) was prepared. The first light and
the second light were irradiated to the bacteria suspension in each
light amount. In this case, the wavelength of the first light was
405 nm and the wavelength of the second light was 275 nm. The
bacteria irradiated with the first light and the second light were
each diluted at a specific concentration, inoculated into agar
plates, and then cultured again. Thereafter, the number of colonies
of the cultured bacteria was identified, and the numerical value
was converted into a log value. Each test was performed under the
same conditions five times.
[0125] Table 2 and FIG. 11A illustrate the test result for the
sterilization power of the first light, and Table 3 and FIG. 11B
illustrate the test result for the sterilization power of the
second light.
TABLE-US-00002 TABLE 2 Light amount (J/cm.sup.2) 0 30 60 90 120
Bacteria Count 7.00 5.97 5.78 5.15 4.17 Error 0.00 0.32 0.35 0.43
0.29
[0126] It may be recognized from Table 2 and FIG. 11A that, as an
amount of the first light, which is irradiated, is increased, the
bacteria count is reduced. It is clear that the bacteria count is
reduced even if the margin of error is considered.
TABLE-US-00003 TABLE 3 Light amount (J/cm.sup.2) 0 1 2 3 Bacteria
Count 7.00 6.23 5.88 5.45 Error 0.00 0.23 0.27 0.18
[0127] It may be recognized from Table 3 and FIG. 11B that, as an
amount of the second light, which is irradiated, is increased, the
bacteria count is reduced. It is clear that the bacteria count is
reduced even if the margin of error is considered. In addition, it
is recognized that the second light sterilizes the bacteria with an
amount smaller than an amount of the first light.
Experimental Example 3--Sterilization Power Test in the Combination
of the First Light and the Second Light
[0128] In the present test, an MRSA strain was used as a pathogen.
After the MRSA strain was cultured, a suspension having a constant
bacteria concentration (7 log) was prepared. The individual
irradiation of the first light, the individual irradiation of the
second light, and the combination of the first light and the second
light were performed with respect to the bacteria suspension.
Comparative Example 1 illustrates that non-light is irradiated to
the bacteria suspension, Comparative example 2 illustrates that the
second light was individually irradiated to the bacteria
suspension, Comparative example 3 illustrates that the first light
was individually irradiated to the bacteria suspension, and
Embodiment illustrates that the combination of the first light and
the second light was irradiated to the bacteria suspension. In this
case, the wavelength of the first light was 405 nm, the dose of the
first light was 120 J/cm.sup.2, and the wavelength of the second
light was 275 nm, and the dose of the second light was 3
mJ/cm.sup.2. In Embodiment, the second light was irradiated in the
dose of 3 mJ/cm.sup.2 and then the first light was irradiated in
the dose of 120 J/cm.sup.2. Next, in Comparative Examples 1 to 3
and Embodiment, the bacteria were diluted at a constant
concentration, inoculated into agar plates, and then cultured
again. Thereafter, the number of colonies of the cultured bacteria
was identified, and the numerical value was converted into a log
value.
[0129] Each test was performed under the same conditions five
times.
[0130] FIG. 12A and Table 4 illustrate the bacteria count in the
individual irradiation of the first light, the individual
irradiation of the second light, and the irradiation of the
combination of the first light and the second light. FIG. 12B and
Table 5 illustrate the sterilization power in the individual
irradiation of the first light, the individual irradiation of the
second light, and the irradiation of the combination of the first
light and the second light.
TABLE-US-00004 TABLE 4 Comparative Comparative Comparative Light
condition Example 1 Example 2 Example 3 Embodiment Bacteria Count
7.00 5.45 4.17 2.83 Error 0.00 0.18 0.29 0.37
TABLE-US-00005 TABLE 5 Comparative Comparative Comparative Light
condition Example 1 Example 2 Example 3 Embodiment Sterilization
0.00 1.55 2.83 4.17 power Error 0.00 0.18 0.29 0.37
[0131] Referring to FIGS. 12A, 12B, Table 4, and Table 5, about 90%
of sterilization power was illustrated in the individual
irradiation of the second light, about 99% of sterilization power
was illustrated in the individual irradiation of the first light,
and 99.99% or more of sterilization power was illustrated in
irradiation of the combination of the first light and the second
light. Accordingly, it may be recognized that an amount of bacteria
is significantly reduced, and thus the sterilization power is
significantly increased when the combination of the first light and
the second light is irradiated, as compared to when the light is
not irradiated, and to when the first light or the second light is
individually irradiated.
Experimental Example 4-Test for Variation in Sterilization Power
Based on Sequence of Combining the First Light and the Second
Light
[0132] In the present test, an MRSA strain was used as a pathogen.
After the MRSA strain was cultured, a suspension having a constant
bacteria concentration (7 log) was prepared. After the second light
was irradiated to the bacteria suspension, the first light was
irradiated to the bacteria suspension. In addition, the second
light was irradiated to the bacteria suspension after the first
light was irradiated to the bacterial suspension. Comparative
example 1 illustrates that non-light was irradiated to the bacteria
suspension, Embodiment 1 illustrates that the first light was
irradiated to the bacteria suspension after the second light was
irradiated to the bacteria suspension, and Embodiment 2 illustrates
that the second light was irradiated to the bacteria suspension
after the first light was irradiated to the bacteria
suspension.
[0133] In Embodiment 1, after the second light having the
wavelength of 275 nm was irradiated to the bacteria suspension with
a dose of 3 mJ/cm.sup.2, the first light having the wavelength of
405 nm was irradiated to the bacteria suspension with a dose of 120
J/cm.sup.2. In Embodiment 2, after the first light having the
wavelength of 405 nm was irradiated to the bacteria suspension with
a dose of 120 J/cm.sup.2, the second light having the wavelength of
275 nm was irradiated with the dose of 3 mJ/cm.sup.2.
[0134] Next, in Comparative Example, Embodiment 1, and Embodiment
2, the bacteria were diluted at a constant concentration,
inoculated into agar plates, and then cultured again. Thereafter,
the number of colonies of the cultured bacteria was identified, and
the numerical value was converted into a log value.
[0135] Each test was performed under the same conditions five
times.
[0136] FIG. 13A and Table 6 illustrate the bacteria count when the
sequence of combining the first light and the second light is
differently set, and FIG. 13B and Table 7 illustrate the
sterilization power when the sequence of combining the first light
and the second light is differently set.
TABLE-US-00006 TABLE 6 Comparative Light condition Example
Embodiment 1 Embodiment 2 Bacteria Count 7.00 2.83 0.00 Error 0.00
0.37 0.00
TABLE-US-00007 TABLE 7 Comparative Light condition Example
Embodiment 1 Embodiment 2 Sterilization power 0.00 4.17 7.00 Error
0.00 0.37 0.00
[0137] It may be recognized from FIGS. 13A, 13B, Table 6, and Table
7 that Embodiment 1 illustrates 99.99% of sterilization power, and
bacteria are not observed in Embodiment 2, so the sterilization is
substantially completely achieved.
[0138] In other words, the case that the second light is irradiated
after the first light is irradiated shows significantly higher
sterilization power with the same irradiation amount of light, as
compared to the case the first light is irradiated after the second
light is irradiated, which means that the same sterilization power
is obtained with a smaller amount of light as compared to the case
the first light is irradiated after the second light is irradiated.
The application of a smaller amount of light means the reduction in
the light irradiation time. Accordingly, Embodiment 2 is more
reduced in the light irradiation time than Embodiment 1.
Experimental Example 5--Setting Condition of an Amount of Light (In
Vitro)
[0139] The bacteria count and the sterilization power were measured
as function of an amount of light in vitro condition when the first
light and the second light are sequentially irradiated, in order to
find out the optimal amount of each light, based on that the
sequential irradiation of the first light and the second light,
which shows the increase in the sterilization power.
[0140] In the present test, an MRSA strain was used as a pathogen.
After the MRSA strain was cultured, a suspension having a constant
bacteria concentration (7 log) was prepared. The first light and
the second light were sequentially irradiated to the bacteria
suspension by changing the dose of the first light to 30
J/cm.sup.2, 60 J/cm.sup.2, 90 J/cm.sup.2, and 120 J/cm.sup.2.
However, in the case of the second light, the light of 275 nm was
employed with a dose limited to 3 mJ/cm.sup.2 based on the
allowable level of the human body.
[0141] Next, the bacteria were diluted at a constant concentration,
inoculated into agar plates, and then cultured again. Thereafter,
the number of colonies of the cultured bacteria was identified, and
the numerical value was converted into a log value.
[0142] Each test was performed under the same conditions five
times.
[0143] FIG. 14A and Table 8 show the bacteria count when an amount
of the first light is variably set while the first light and the
second light are sequentially irradiated, and FIG. 14B and Table 9
show the sterilization power when an amount of the first light is
variably set while the first light and the second light are
sequentially irradiated.
TABLE-US-00008 TABLE 8 Light amount (J/cm.sup.2) 0 30 60 90 120 The
number of bacteria 7.00 3.47 2.13 1.70 0.00 Error 0.00 0.13 0.27
0.22 0.00
TABLE-US-00009 TABLE 9 Light amount (J/cm.sup.2) 0 30 60 90 120
Sterilization power 0.00 3.53 4.87 5.03 7.00 Error 0.00 0.13 0.27
0.22 0.00
[0144] It may be recognized from FIGS. 14A, 14B, Table 8, and Table
9 that the number of bacteria is reduced as an amount of the first
light is increased and the sterilized is completely achieved with a
dose of 120 J/cm.sup.2.
Experimental Example 6--Setting of Light Amount Condition (In
Vivo)
[0145] It was recognized through Embodiment 4 that the
sterilization is completely achieved when a dose of the first light
(having the wavelength of 275 nm) is 120 J/cm.sup.2, under the
condition that the dose of the second light (having the wavelength
of 405 nm) is 3 mJ/cm.sup.2. Accordingly, the test was performed to
determine whether the above sterilization effect is obtained under
in vivo condition.
[0146] The present test was performed using a mouse to determine
whether the application of light is effective and safe under in
vivo condition. The condition for an amount of light is set to the
same condition as that in vitro. For a mouse, a BALB/c mouse (6-8
weeks old) was used, the back of the mouse was shaved, and then a
cut was formed in the diameter of 10 mm in the back of the mouse.
After the pathogenic bacteria was inoculated (at 5 log) on the
wound, the first light and the second light were sequentially
irradiated by changing the dose of the first light to 30
J/cm.sup.2, 60 J/cm2, 90 J/cm2, and 120 J/cm2. However, in the case
of the second light, the light of 275 nm was employed with a dose
limited to 3 mJ/cm.sup.2 based on the allowable level of the human
body. Next, tissues were sampled, and the sampled tissues were
disrupted, diluted at a predetermined concentration, inoculated on
agar plates, and then cultured again. Thereafter, the number of
colonies of the cultured bacteria was identified, and the numerical
value was converted into a log value.
[0147] Each test was performed under the same conditions five
times.
[0148] FIG. 15A and Table 10 show the bacteria count as a function
of an amount of the first light, when the first light and the
second light were sequentially irradiated. FIG. 15B and Table 11
show the sterilization power as a function of an amount of the
first light, when the first light and the second light were
sequentially irradiated.
TABLE-US-00010 TABLE 12 Light amount (J/cm.sup.2) 0 30 60 90 120
Bacteria Count 5.00 3.17 3.32 1.48 0.00 Error 0.00 0.36 0.38 0.31
0.00
TABLE-US-00011 TABLE 13 Light amount (J/cm.sup.2) 0 30 60 90 120
Sterilization power 0.00 1.83 1.68 3.52 5.00 Error 0.00 0.36 0.38
0.31 0.00
[0149] It may be recognized from FIGS. 15A, 15B, Table 10, and
Table 11 that the bacteria count is reduced as an amount of the
first light is increased under in vivo condition and the sterilized
is completely achieved with a dose of 120 J/cm.sup.2.
Experimental Example 7--Effectiveness Evaluation 1 (In Vivo)
[0150] In embodiment 5, a dose of light for sterilization was
recognized under in vivo condition, and the variation in the
sterilization power and the variation in the bacteria count as
functions of time were tested under in vivo condition.
[0151] The present test was performed using a mouse. For the mouse,
a BALB/c mouse (6-8 weeks old) was used, the back of the mouse was
shaved, and then a cut was formed in the diameter of 10 mm in the
back of the mouse. After the pathogenic bacteria was inoculated (at
5 log) on the wound, the first light and the second light were
sequentially irradiated and repeatedly irradiated six times in
total at the same time every day while a dose of the first light
(having the wavelength of 405 nm) is 120 J/cm.sup.2. In the case of
the second light, the light of 275 nm was employed with a dose
limited to 3 mJ/cm.sup.2 based on the allowable level of the human
body.
[0152] Next, to determine the bacteria count every day, tissues
were sampled, and the sampled tissues were disrupted, diluted at a
predetermined concentration, inoculated on agar plates, and then
cultured again. Thereafter, the number of colonies of the cultured
bacteria was identified, and the numerical value was converted into
a log value. To determine the initial sterilization power, the
bacteria count was detected until three-time light irradiation.
[0153] FIG. 16 and Table 14 show the variation in the sterilization
power depending on days under in vivo condition, and FIG. 17 and
Table 15 show the measurement result of the number of bacteria in
each day under in vivo condition. In FIG. 17 and Table 15,
Comparative example is a non-irradiation group without light
irradiation, and Embodiment corresponds to a light irradiation
group irradiated with light.
TABLE-US-00012 TABLE 14 Day Inoculation 0 1 2 Sterilization power
0.00 5.00 4.09 5.29 Error 0.00 0.00 0.13 0.09
TABLE-US-00013 TABLE 15 The number of bacteria (%) The number of
bacteria (log) Day Inoculation 0 1 2 Inoculation 0 1 2 Non- 100 100
4,466 173,780 5.00 5.00 6.65 8.24 irradiation group Light 100 0
0.36 0.89 5.00 0.00 2.56 2.95 irradiation group
[0154] It may be recognized from FIG. 16, FIG. 17, Table 14, and
Table 15 that the sterilization power is continuously maintained to
99.99% or more after light is irradiated to the wound at the
initial stage, and the number of bacteria is substantially
approximate to `0` when the light is irradiated.
Experimental Example 8--Effectiveness Evaluation 2 (In Vivo)
[0155] In Embodiment 5, a dose of light for sterilization was
recognized under in vivo condition, and the effect of treating the
wound by irradiating the light was tested under in vivo condition
based on the dose of light for sterilization.
[0156] The present test was performed using a mouse. For the mouse,
a BALB/c mouse (6-8 weeks old) was used, the back of the mouse was
shaved, and then a wound was formed in the diameter of 10 mm in the
back of the mouse. After the pathogenic bacteria was inoculated (at
5 log) on the wound, the first light and the second light were
sequentially irradiated and repeatedly irradiated six times in
total at the same time every day while a dose of the first light
(having the wavelength of 405 nm) is 120 J/cm.sup.2. However, in
the case of the second light, the light of 275 nm was employed with
a dose limited to 3 mJ/cm.sup.2 based on the allowable level of the
human body.
[0157] The variation in the shape (especially, an area) of the
wound was observed at the same time every day. The size of the
wound was observed every day till epithelialization, and the value
thereof was recorded.
[0158] FIG. 18 and Table 16 show the variation in the area of a
wound depending on days under in vivo condition. In FIG. 18 and
Table 16, Comparative example is a non-irradiation group without
light irradiation, and Embodiment corresponds to a light
irradiation group irradiated with light. FIGS. 19A and 19B are
photographs obtained by capturing images of the shape of the wound
area depending on days. FIG. 19A illustrates photographs of a wound
in the non-irradiation group, and FIG. 19B illustrates photographs
of wounds in the light irradiation group.
TABLE-US-00014 TABLE 16 Day Inoculation 0 2 3 6 10 15 Non- 100.0
100.0 108.8 93.8 83.3 55.9 22.4 irradiation group Error 7.8 7.8 7.0
5.0 3.8 2.7 4.2 Light 100.0 100.0 101.0 82.1 50.3 28.8 0.0
irradiation group Error 7.8 7.8 4.1 3.6 1.9 3.2 0.0
[0159] Referring to FIG. 18, Table 16, FIG. 19A, and FIG. 19B, the
wound cured was not visibly observed until 2 days from the wound,
and the bacteria count in the wound was significantly reduced.
Accordingly, it was determined that the sterilization was in
progress. A scab was produced from 2 days after the wound and then
the area of the wound was gradually reduced. Accordingly, the
curing of the wound is in progress from 2 days after the wound.
When the scab was produced on the wound, the wound exposed to the
outside was disappeared by the scab. Therefore, the additional
infection is less caused. However, the size of the scab and the
recovery rate of the wound greatly varied depending on the
sterilization state until the scab was formed. Although the light
irradiation group required 6 days till a time point at which the
area of the wound was reduced to 50% in the stage of curing the
wound, the non-irradiation group required 10 days till the time
point. Further, the epithelialization was achieved on the 15.sup.th
day in the case of the light irradiation group, and not achieved in
the case of the non-irradiation group. Accordingly, according to an
embodiment of the present disclosure, it may be recognized that the
effect of curing the wound is significantly produced when light is
irradiated.
Experimental Example 9--Safety Evaluation 1 (In Vivo)
[0160] In the above-described experimental example, a DNA mutation
state was determined to determine whether the irradiation condition
is harmful to the human body.
[0161] In the present test, to determine whether the DNA mutation
was caused to the tissue which is not infected through light
irradiation, the formation degree of a thymine dimer was determined
through immunohistochemical analysis. When an excessive amount of
UV is irradiated to the DNA, the DNA mutation such as the thymine
dimer is caused, so the cell is destroyed. Accordingly, the DNA
mutation may be determined based on the formation degree of the
thymine dimer.
[0162] The present test was performed using a mouse. For the mouse,
a BALB/c mouse (6-8 weeks old) was used, the back of the mouse was
shaved, and then a wound is formed in the diameter of 10 mm in the
back of the mouse by using the punch. After light was irradiated on
the wound, the tissue was sampled, the sampled tissue was fixed
through formalin and paraffin, and a cut-out fragment was taken.
When light was irradiated, the control group was a non-irradiation
group in which light was not treated, Experimental group 1 was a
light irradiation group in which an excessive amount of UVC was
treated, Experimental group 2 was a light irradiation group in
which the first light and the second light were sequentially
irradiated in the state that a dose of the first light (having the
wavelength of 405 nm) is limited to 120 J/cm.sup.2 and, a dose of
the second light (having the wavelength of 275 nm) is limited to 3
mJ/cm.sup.2.
[0163] FIG. 20A and Table 17 illustrate the percentage of a thymine
dimer in a tissue. Referring to FIG. 20A and Table 17, although the
thymine dimer was found in Experimental group 1, the thymine dimer
was not found in Experimental group 2. Accordingly, under the light
condition applied according to the embodiments of the present
disclosure, it was determined that the DNA mutation was not found
even if the light was irradiated to a tissue which was not
infected.
TABLE-US-00015 TABLE 17 Control Experimental Experimental group
group 1 group 1 Content (%) 2 58 3 Error 1 8 1
Experimental Example 10--Safety Evaluation 1 (In Vivo)
[0164] In the above-described experimental example, the generation
state of ROS was determined to determine whether the irradiation
condition was harmful to the human body.
[0165] The present test is to determine whether the ROS was induced
even in the tissue, which was not infected, through light
irradiation. When the sterilizing light was irradiated to the
infectious bacteria, the ROS was induced to destroy the
bacteria.
[0166] The present test was performed using a mouse. For the mouse,
a BALB/c mouse (6-8 weeks old) was used, the back of the mouse was
shaved, and then a wound is formed in the diameter of 10 mm in the
back of the mouse by using the punch. After the light was
irradiated on the wound, a Dichlorofluorescin diacetate (DCFH-DA)
was treated for a part irradiated with light and a light emission
was measured with respect to a part stained with DCFH-DA, so it was
determined that the ROS was present. DCFH-DA was oxidized by the
ROS in the cell to emit fluorescent light. When DCFH-DA was
excited, the absorption wavelength was in the range of 445 nm to
490 nm, and the fluorescent wavelength was in the range of 515 nm
to 575 nm.
[0167] In this case, the control group was a non-treatment group in
which non-treatment is added, Experimental group 1 was a group
treated with hydrogen peroxide, and Experimental group 2 was a
treatment group to which the first light and the second light are
sequentially irradiated in the state that a dose of the first light
(having the wavelength of 405 nm) is limited to 120 J/cm.sup.2, and
a dose of the second light (having the wavelength of 275 nm) is
limited to 3 mJ/cm.sup.2.
[0168] FIG. 20B and Table 18 illustrate the light emission degree
of a part stained with DCFH-DA. Referring to FIG. 20B and Table 18,
fluorescent is emitted in Experimental group 2 and Experimental
group 1, so it is determined that ROS is present. However, since
fluorescent is not absent in Experiment group 2, so it is
determined that ROS is absent. Accordingly, under the light
condition applied according to the embodiments of the present
disclosure, it was determined that the ROS was not produced even if
the light was irradiated to a tissue which was not infected.
TABLE-US-00016 TABLE 18 Control Experimental Experimental group
group 1 group 2 Light emission degree 0 1.5 0 (RLU; relative light
units) Error 0 0.3 0
[0169] Although an exemplary embodiment of the present disclosure
has been described for illustrative purposes, those skilled in the
art will appreciate that various modifications, and substitutions
are possible, without departing from the scope and spirit of the
invention as disclosed in the accompanying claims. Accordingly, the
technical scope of the present disclosure is not limited to the
detailed description of this specification, but should be defined
by the claims.
* * * * *