U.S. patent application number 13/083753 was filed with the patent office on 2011-09-01 for phototherapy method for treating psoriasis.
This patent application is currently assigned to LEDeep LLC. Invention is credited to Peter Depew Fiset.
Application Number | 20110212410 13/083753 |
Document ID | / |
Family ID | 34976186 |
Filed Date | 2011-09-01 |
United States Patent
Application |
20110212410 |
Kind Code |
A1 |
Fiset; Peter Depew |
September 1, 2011 |
PHOTOTHERAPY METHOD FOR TREATING PSORIASIS
Abstract
A system and method for phototherapy, including skin tanning,
lupus phototherapy, teeth whitening, hair growth and psoriasis
therapies, are provided. The system includes a chamber adapted for
at least one type of phototherapy and at least one UV LED, at least
one nanostructure UV light emitting device or a combination of UV
LEDs and nanostructure UV light emitting devices.
Inventors: |
Fiset; Peter Depew;
(Loudonville, NY) |
Assignee: |
LEDeep LLC
|
Family ID: |
34976186 |
Appl. No.: |
13/083753 |
Filed: |
April 11, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10591960 |
Jun 25, 2007 |
7921853 |
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PCT/US2005/007708 |
Mar 9, 2005 |
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13083753 |
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PCT/US2004/016299 |
May 24, 2004 |
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10591960 |
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PCT/US2004/014527 |
May 24, 2004 |
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PCT/US2004/016299 |
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60552018 |
Mar 9, 2004 |
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Current U.S.
Class: |
433/29 ;
607/94 |
Current CPC
Class: |
A61N 2005/0653 20130101;
B82Y 5/00 20130101; B82Y 30/00 20130101; A61N 5/0614 20130101; A61N
5/0616 20130101; A61N 2005/0652 20130101; A61N 5/0617 20130101;
A61N 2005/0629 20130101; A61N 2005/0661 20130101; A61C 19/066
20130101 |
Class at
Publication: |
433/29 ;
607/94 |
International
Class: |
A61N 5/06 20060101
A61N005/06; A61C 19/06 20060101 A61C019/06 |
Claims
1.-57. (canceled)
58. A system, comprising: a chamber; and a light emitting device
disposed in the chamber; wherein: the light emitting device
comprises a nanostructure light emitting device or a light emitting
diode (LED); and the light emitting device emits: a) light in a UV
wavelength range suitable for performing lupus phototherapy; b)
light in a UV wavelength range suitable for performing psoriasis
phototherapy; c) light in a UV wavelength range suitable for
inducing hair growth; or d) light in a UV or blue wavelength range
suitable for performing tooth whitening phototherapy in conjunction
with a tooth whitening agent.
59. The system of claim 58, wherein the chamber comprises a bed or
a booth.
60. The system of claim 58, wherein the light emitting device
comprises at least one of a nanoparticle or a nanowire
nanostructure UV light emitting device.
61. The system of claim 60, further comprising a UV excitation
source which is positioned to provide UV excitation radiation of a
first peak wavelength onto the nanostructure UV light emitting
device to cause the nanostructure UV light emitting device to emit
UV light having a second UV peak wavelength longer than the first
peak wavelength.
62. The system of claim 58, wherein the light emitting device
comprises a LED.
63. The system of claim 58, wherein the light comprises light with
a wavelength of about 340 nm to about 400 nm suitable for
performing lupus phototherapy.
64. The system of claim 58, wherein the light has an emission peak
at or between 312 and 311 nm and a full width half maximum of about
0.1 to about 2 nm suitable for performing psoriasis
phototherapy.
65. The system of claim 58, wherein the light is suitable for
inducing hair growth in conjunction with a hair growth assistance
chemical which undergoes a hair growth stimulating reaction when
exposed to the light.
66. The system of claim 58, wherein the light comprises light in
the UV or blue wavelength range suitable for performing tooth
whitening phototherapy in conjunction with a tooth whitening
agent.
67. The system of claim 58, wherein the light emitting device is
adapted to provide light having an adjustable wavelength range.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims benefit of U.S. Provisional
Patent Application Ser. No. 60/552,018, filed Mar. 9, 2004; PCT
Patent Application Number PCT/US2004/014527, filed May 24, 2004;
PCT Patent Application Number PCT/US2004/016299, filed May 24,
2004, which are incorporated by reference in their entirety.
FIELD OF THE INVENTION
[0002] The present invention is directed generally to phototherapy
systems and specifically to systems for treating lupus and
psoriasis, for whitening teeth and for inducing hair growth.
BACKGROUND
[0003] The most common method of skin tanning involves the process
of exposing skin to ultra-violet light. Health research has shown
that both the condition of under-exposure to ultra-violet light and
the condition of over-exposure to ultra-violet light causes a
variety of health problems. Health research has also shown that
specific ranges of wavelengths of ultra-violet light are
responsible for producing health benefits. Moderate exposure to
specific wavelengths of ultra-violet light produces the greatest
benefits with the least amount of health risk. Certain methods and
devices are useful at controlling the quantity and quality of
ultra-violet light exposure in the effort to produce the greatest
health benefits with the least amount of health risks. Ultra-violet
light quality depends primarily on the ranges of wavelength of
ultra-violet light; where the highest ultra-violet light quality is
the ultra-violet light that produces the greatest net health
benefits.
[0004] The sun is a primary source of ultra-violet light for
tanning. The quantity of light exposure to the sun is simple to
control. The quality of ultra-violet light exposure by the sun is
not simple to control. Lamps that provide alternative sources of
ultra-violet light allow for tanning services that do not rely on
the sun. These tanning services are available and are administered
in a controlled environment such as in personal care service
salons. The industry providing controlled exposure to artificial
ultra-violet light is generally referred to as the "indoor-tanning"
industry. Indoor-tanning does not implement systems that are
directly dependent on the sun as the source of ultra-violet
radiation. The quality of the indoor-tanning ultra-violet light has
become important in differentiating services available within the
same indoor-tanning salon and between competing tanning salons.
[0005] Light with wavelengths in the ultra-violet range is often
referred to as UV light or UV. UVA, UVB and UVC describe three
separate non-overlapping but adjacent ranges of light fully
encompassing the UV light range. The range of light referred to as
UVA generally has the longest set of wavelengths within the UV
range and includes wavelengths between 290 and 400. UVA-1 is
between 340 and 400; UVA-2 is between 290 and 340; and UVA-3 is
between 290 and 310. The range of light referred to as UVC
generally has the shortest set of wavelengths within the UV range
and includes wavelengths between 160 and 260. The range of light
referred to as UVB includes wavelengths between 260 and 290.
[0006] The use of the terms UVA, UVB and UVC allow the various
properties of UV light to be categorized in general ways. UVA has
the best capability of tanning skin. UVB does not produce a tan in
the third layer of skin. UVC light does not produce a tan but can
sterilize some biological agents such as certain bacteria. Under
certain conditions UVB will tan the second layer of skin. The
second layer of skin when tanned with UVB has a shedding period of
5 to 8 days. Skin tanned with UVA only has the third layer of skin
tanned which results in a normal shedding cycle of 28 days.
[0007] A light therapy is a method of applying a specific set of
wavelengths of electromagnetic radiation in specific states and
under specific conditions to produce a change in a bodily function.
Tanning is a light therapy whereby the biological change is the
production of melanin within the cells of the skin. Indoor-tanning
is a light therapy utilizing the exposure of moderate amounts of UV
over a reasonable amount of time to skin from UV sources other than
the sun.
[0008] Under normal conditions the outer layer of skin, also known
as the first layer, is composed of dead cells. Normally, dead cells
will not produce melanin upon exposure to moderate amounts of UV.
The layer under the first layer of skin is referred to as the
second layer of skin, and is composed of active cells that may be
functioning in some biological manner and will produce melanin upon
exposure to UVB light. UVB skin tanning has, what some tanners
consider, an additional negative effect, UVB tanning will thicken
the second layer of skin and as a result increases the visibility
of skin lines and wrinkles. UVB tanning creates a shedding cycle of
5 to 7 days which is undesirable when a UVA tan has a shedding
cycle of 28 days. When UVB is combined with UVA the shedding cycle
of the UVA tanned layer is accelerated since the second layer is
shed more quickly and the third layer becomes the second layer as a
result and is shed within another 5 to 7 days.
[0009] Under normal conditions the layer of skin that will produce
melanin (melanogenesis) when exposed to UVA-3 or UVB light is
referred to as the third layer of skin and more specifically the
melanocytes within the skin. The Vitamin-D production is believed
to be caused by exposure to UVA-3 or UVB light. However, UVB light
can also degrade Vitamin-D. Since UVA-3 does not degrade Vitamin-D,
UVA-3 is preferred over UVB for Vitamin-D production and
melanogenesis. The selective elimination of UVB and selective
production of UVA-1, UVA-2 and UVA-3 can be a benefit of the
present invention. Melanogenesis is important for tanners who
desire a darker tan than that which is obtained from UVA-1 or UVA-2
exposure alone. UVA-1 and UVA-2 converts melanin into the dark
pigment melatonin. The Tanning Industry Association promotes a
skin-type classification based on the amount of melanin present in
the skin before additional melanin has been created by
melanogenesis. These types include type I (little), II (low), III
(moderate), IV (high) and V (black). In exceptional conditions such
as albinism, the third layer of skin is not capable of producing
melanin. For the purposes of this application, albino skin is
considered an exception to the norm and will not be referred to as
a third layer of skin but as an albino third layer of skin.
[0010] It is common knowledge that all wavelengths of UV over long
exposure periods damages the skin in various ways. Therefore, it is
desirable to limit the exposure of UV radiation to skin.
Alternatively, some UV exposure is generally considered necessary
in order to maintain good health in other bodily functions, such as
the generation of vitamin-D. Vitamin-D is useful in the absorption
of calcium in the body. Therefore, it has been recommended by
various health organizations studying the phenomena that moderate
exposure to UV light has a net health benefit, whereas
over-exposure or under-exposure of UV results in a net health
deficit. The art of indoor-tanning to remain useful should provide
for ever increasing controllability of the application of the light
therapy. As a light therapy tanning should be applied with specific
goals and procedures to maximize the benefits of the therapy.
[0011] For people desiring a tan, the main benefits of UV exposure
is the production of tanned skin. Tanners enjoy positive
psychological and perceived positive social benefits resulting from
having tanned skin. In order to limit the total amount of UV
radiation tanners are exposed to while maintaining a tan, it is
desirable to reduce as much as possible the exposure to UV light
outside the UVA wavelength range. UVB and UVC wavelength ranges of
radiation are by definition not capable of tanning skin with a 28
day shedding cycle and therefore reasonable efforts should be made
to eliminate UVB and UVC from the source of light tanners are
exposed to.
[0012] Indoor-tanning methods generate UV light from converting
electrical energy to light within devices such as UV fluorescent
bulbs and high and low pressure mercury vapor bulbs are two
specific types of light bulb technologies. UV light bulbs currently
in use have properties of high voltage, high temperature, and low
electrical energy to UV conversion efficiencies under seventeen
percent.
[0013] Within the fluorescent light bulb category there are a
variety of types that differ mainly in the percentage of UV light
produced in the UVA, UVB and UVC wavelength ranges. For tanners
concerned with overexposure to UV light the more desirable
fluorescent bulbs have a higher percentage of light in the UVA-1
wavelength range. Tanners concerned with overexposure prefer and
tend to pay a premium for tanning services that have the least
amount of UVB and UVC.
[0014] Depending on weather conditions, typically 88% of the UV
radiation from the sun is UVA, in this case an artificial source
with more than 88% of the UV radiation is UVA is considered a safer
tanning method than sun-tanning. Common fluorescent tanning bulbs
and associated services have UV composed between 92.0% UVA to 97.5%
UVA. Currently, high pressure quartz metal-halogenide bulbs have in
general 98.5% UVA and are considered to be the least harmful
artificial tanning bulbs currently used in indoor-tanning
salons.
BRIEF SUMMARY OF THE INVENTION
[0015] A preferred embodiment of the present invention provides a
system for phototherapy, including skin tanning, lupus
phototherapy, hair regrowth phototherapy, teeth whitening
phototherapy and psoriasis phototherapy. The system comprises a
chamber adapted for at least one of these phototherapies, and at
least one light emitting diode emitting UV light, at least one
nanostructure UV light emitting device, or a combination of one or
more light emitting diode emitting UV light with one or more
nanostructure UV light emitting devices.
[0016] Another preferred embodiment of the present invention
provides a system for phototherapy, including skin tanning, lupus
phototherapy, hair regrowth phototherapy, teeth whitening
phototherapy and psoriasis phototherapy. The system comprises a
first means for at least one of skin tanning and phototherapy, and
at least one light emitting diode emitting UV light, at least one
nanostructure UV light emitting device or a combination of one or
more light emitting diode emitting UV light with one or more
nanostructure UV light emitting devices.
[0017] Another preferred embodiment of the present invention
provides a method for conducting phototherapy, including skin
tanning, lupus phototherapy, hair regrowth phototherapy, teeth
whitening phototherapy and psoriasis phototherapy. The method
comprises providing UV light from at least one light emitting diode
emitting UV light, at least one nanostructure UV light emitting
device or a combination of one or more light emitting diode
emitting UV light with one or more nanostructure UV light emitting
devices onto a skin of a human subject who is located in a chamber
adapted for at least one of these phototherapies in order to
provide phototherapy for the skin.
[0018] For illustrative purposes, the devices, systems and methods
of the present invention are sometimes described as including at
least one light emitting diode that emits UV light or at least one
nanostructure UV light emitting device. However, it should be
understood that each of the embodiments described herein may be
modified to include a combination of one or more light emitting
diode emitting UV light with one or more nanostructure UV light
emitting devices to provide a UV light source. In addition, each of
these embodiments may be modified to include other light sources
including, but not limited to, visible LEDs, infrared LEDs,
fluorescent bulbs, mercury vapor based bulbs and combinations
thereof in order to provide a desired spectral distribution for a
given phototherapy application or for general lighting
applications.
[0019] Unless otherwise noted, any values for wavelengths in this
disclosure are provided in nanometers (nm).
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 shows an electrical schematic diagram for powering
the LEDs. Also shown is a variable power supply which charges
capacitors in a selective manner.
[0021] FIG. 2 shows an electrical schematic diagram of a LED power
control circuit.
[0022] FIG. 3 shows an electrical schematic diagram of a LED power
control circuit.
[0023] FIG. 4 shows an electrical schematic diagram of a LED power
control circuit Also shown are permanently mounted connector and
portable connector which allows said external light output feedback
sensor to be moved around within the tanning chamber and removed
from the tanning chamber.
[0024] FIGS. 5A and 5B are schematic side views of systems
according to embodiments of the present invention.
[0025] FIGS. 6, 7, 8A, 8B, 9 and 10 are cross sectional side views
of nanostructure UV light emitting devices according to embodiments
of the present invention.
[0026] FIG. 11 is a bottom view of a nanostructure UV light
emitting device according to an embodiment of the present
invention.
[0027] FIGS. 12-15 show various power sources that may be used to
power the LEDs in the systems and devices described herein.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0028] Some aspects of the present invention provide systems,
devices and methods for use in phototherapies and in general
purpose lighting applications. The systems and devices are based on
UV emitting LEDs, UV emitting nanostructures, or a combination of
the two. The use of UV emitting LEDs and/or UV emitting
nanostructures provides a significant advantage over other UV
phototherapy and lighting systems and devices because they make it
possible to adjust the width and the wavelength range of the
emission spectrum. For example, the present systems and devices may
by tuned to provide emission bands having single or multiple peaks
or combinations of both. The systems and devices may provide
continuous emission spectra or discrete emission lines, or a
combination of both. Both the amplitudes and full width half
maximum of the bands can be adjusted, resulting in spectral
densities which can be manipulated and programmatically controlled
to vary during a phototherapy session in order to increase the
effectiveness of the phototherapy.
UV LED-Based Phototherapy
[0029] A first aspect of the present invention incorporates the use
or light emitting diodes, commonly referred to as LEDs, into a
phototherapy device that optionally includes other sources of
therapeutic electromagnetic radiation. In some embodiments, for
example, where the device is used in tanning or for the treatment
of lupus, UVA LEDs are preferred. Particularly preferred UVA LEDs
include those that emit at least about 90% UVA wavelengths,
preferably at least about 95% or more UVA wavelengths. In one
embodiment, the LED emits essentially only (e.g., at least about
99.99%) UVA. The various LED manufacturers of the preferred LEDs
are Cree Inc. (USA), Nichia (Japan), Toyoda Gosei (Japan), Crystal
IS (USA-Aluminum Nitride AlN substrate) with Palo Alto Research
Center (USA).
[0030] For providing some phototherapies other than or in addition
to tanning and lupus therapy, it may be desirable to include LEDs
that have different wavelengths instead of or in addition to UVA,
such as UVB, UVC, violet and blue. Therefore in some of the present
systems provide a mix of various wavelength LEDs that are
incorporated in combinations that suit a particular therapy
requirement. A light therapy device composed of UVA LEDs and other
LEDs and other types of light bulbs is desirable to provide a
variety of desired therapeutic effects. When the desired effect is
tanning skin or lupus therapy then a portion of the LEDs are of the
UVA LED variety. In general, UVA LEDs are used in combination with
other light sources to produce a combination light therapy in a
selectable and controllable manner. Light therapy devices with
multiple and varied types of lamps include selectable power
supplies that control how and when the various lamps are powered.
Some devices, such as those for use in teeth whitening, hair
regrowth and psoriasis therapies, may be designed with selectively
controllable UVA LEDs such that they provide selectable treatment
areas (e.g., on the teeth, scalp or area of psoriasis) and reduced
power when treatment is not required at various points within the
chamber.
[0031] There are many advantages of LEDs over light bulbs. LEDs are
more efficient at converting electrical energy into directed light
than many other UV light bulb types. LEDs do not require surfaces
operating at high temperatures and can be safer. LEDs do not
require high voltages or high currents to operate and, for this
reason, LEDs are safer and require less structure to protect the
people in proximity to the light source. Additionally, LEDs can be
smaller than light bulbs. As discrete components LEDs may be
fabricated as arrays in a wide variety of shapes and form factors,
including a fluorescent bulb form factor, an industry standard
light bulb, or an industry standard spot light bulb.
[0032] In a fluorescent bulb form factor the UV LED arrays can
contain an internal power conversion or external power conversion
(or a combination of internal and external power conversion) and
directly replace a UV fluorescent bulb in currently installed
tanning devices currently made for indoor-tanning devices. In this
manner, conventional tanning devices may be readily converted into
phototherapy devices for a range of treatments, including teeth
whitening, hair regrowth and psoriasis therapies. Current
indoor-tanning devices for the prone body position are commonly
referred to as tanning beds. Current indoor-tanning devices for
upright body positions are commonly referred to as tanning booths.
Collectively, tanning booths and tanning beds are referred to as
tanning chambers.
[0033] In ideal conditions, UV LED semiconductor chips have a
lifetime on the order of 100,000 hours. Encapsulated LEDs have an
epoxy or plastic encapsulation. The encapsulated UV LEDs have an
effective lifetime of 10,000 hours due to degradation of the
encapsulation material from UV exposure. The chips within the
encapsulation continue to operate past the 10,000 hours but the UV
degraded encapsulation material does not allow as much UV light to
escape. In order to maintain a calibrated constant total radiant
flux per tanning session over the life of the encapsulated UV LED
based phototherapy device, then either, the corrective action of
increasing the electric current supplied to the LEDs, or the
corrective action of increasing the total number of powered LEDs in
the phototherapy device, or a combination of the corrective actions
must be taken as the encapsulation material degrades. The
wavelength of the UVA does not change significantly over the life
of a UVA LED.
[0034] When used in 5 to 20 minute power cycles common in some
phototherapy chambers, fluorescent light bulbs begin to noticeably
degrade within 100 hours of use and have a total lifetime on the
order of 1000 hours or less, and are very often replaced after 400
total hours of operation creating significant maintenance expenses.
Therefore, there is a greatly reduced amount of maintenance
required with the LED based phototherapy systems as opposed to
fluorescent bulb phototherapy systems. The UVA LED has a consistent
wavelength over the life of the LED, whereas the wavelength varies
for fluorescent bulbs over the life of the fluorescent bulb. The
average wavelength of the fluorescent bulb in the UVA range
decreases and drifts into the UVB range which may result in a
negative effect over the life of the fluorescent bulb, depending
upon the particular phototherapy. Mercury vapor lamps without
phosphors tend to suffer from drawbacks similar to those of
fluorescent bulbs, where UVA and/or UVB output from the mercury
vapor lamps may decrease over their lifetimes. Independent of UVA
LED mounting method, whether encapsulated in UV sensitive material
(epoxy resin) or encapsulated in UV insensitive materials (metal or
plastic housing with quartz lens), the UVA LEDs have a longer
useful life than fluorescent bulbs or mercury vapor lamps.
[0035] As previously stated, UVA LEDs may be used in combination
with other UV producing light sources. LEDs incorporated into light
therapy devices, including tanning, lupus therapy, teeth whitening
therapy, hair regrowth therapy and psoriasis therapy devices, are
not limited to the UVA type only. Other wavelengths LEDs are
incorporated into the device in order to provide other types of
light therapy. In addition to providing additional light therapy
effects, other wavelength LEDs may provide visible light in an
otherwise dark chamber.
[0036] In one embodiment, the LED device is contained in a tube,
such as an acrylic tube, in the form factor of an industry standard
fluorescent bulb with an internal power converter, an optional
internal cooling system, and an optional temperature sensor. In yet
another embodiment, the form is equipped with an internal light
output feedback sensor to control the power to the cooling system
or other fan. Alternatively, an external LED compatible power
supply in the form factor for a high voltage fluorescent bulb
ballast power supply can be used with the LED device in the
fluorescent bulb form factor with house-power volt connector. This
form factor allows for direct replacement of industry standard
fluorescent power ballast when the industry standard fluorescent
bulbs are replaced with LED fluorescent bulb form factors which do
not contain internal power converters. The invention, manufactured
in a standard fluorescent form factor, allows direct replacement
with minimal modification to bulb fixtures already deployed in
tanning chambers.
[0037] An external LED compatible power supply used with a low
voltage LED array can be connected to a house-power connector. A
low voltage LED array does not need an active internal high voltage
power converter and thus has a lower cooling requirement but can
still have an optional fan and optional temperature sensor and
temperature controller.
[0038] In one embodiment, the device is equipped with optional
adjustable rotating electrical connectors, friction plate, and
fastener, allowing for setting arbitrary direction of the LEDs and
circuit board. The device can also be equipped with a porous
end-cap that allows for ventilation, such as passive or active
ventilation. The porous end cap permits air flow when used, for
example, with a fan. The industry standard electrical connection is
composed of metallic pins and insulators, commonly referred to as
Bi-Pin, RD2 and lead wires.
[0039] Flexible electrical connectors are a preferred embodiment,
employing coiled wire but could also be composed of a track and
slider connector for maintaining electrical connection while
allowing for rotation of the end-cap with respect to the circuit
board. The rotating components allows for adjustable directional
alignment of light without having to rotate the connector on the
fixture. In this embodiment, the LED device can advantageously
replace one or more fluorescent bulbs in a typical fluorescent bulb
based tanning chamber.
[0040] The UVA LED based florescent UV bulb replacement apparatus
can come in a number of embodiments. In one embodiment, it
incorporates an external heat sink for cooling of the components.
The built-in power supply conditions house-power or high voltage or
high frequency power into power suitable for driving LED circuits.
A typical UVA LED fluorescent replacement lamp is composed of
thousands of low power UVA LEDs or hundreds of high power UVA LEDs
arrayed on a single fluorescent form factor circuit board. Heat
sinks can be integrated into the UVA LED fluorescent replacement
lamp. Combinations of heat sinks and fans can be integrated into
said present invention. The form factor of the UVA LED fluorescent
replacement lamp is similar to that of the florescent bulbs they
replace but are not necessarily identical. UVA LED replacement
lamps in a fluorescent bulb form factor may replace multiple
fluorescent bulbs with a single set of connectors. The UV LED
replacement fluorescent bulb set apparatus with a single or
multiple sets of rotating electrical connectors can also be used.
Optional modular components can create an arbitrary length of
fluorescent bulb replacement utilizing special sockets, linking
them end to end. Provisions for two-way control signals to
selectively control individual or sub-sets of LEDs within the LED
array can be contained within the connectors. Alternatively, the
power lines can be modulated with two way time or frequency
multiplexed coded signals in such a manner as to provide signal
information to and from an LED power controller in proximity to the
LEDs for the purpose of selectively controlling power to
individuals or sub-sets of the LEDs.
[0041] The form can contain an array of a plurality of LEDs on a
circuit board. The circuit board and LED array can be on one, two
or more sides. The board can be flat, curved, angled (such as an
obtuse or acute angle with one or two sides of the angle presented
with an array). In yet another embodiment, the circuit board LED
array is on one or more sides of a multiple angled circuit board,
such as an open or closed angled circuit board. Where the board is
curved, the curve can be concave, convex, or curvilinear, open or
closed (such as a cylinder) with an array presented on one or both
sides. In yet another embodiment, the circuit board can be flat (or
other configuration), but the LED leads bent to allow direction
orientation of LED, distinct from the board. In yet another
embodiment, the circuit board is flexible, permitting bending,
folding and/or formation to a desired contour. In yet another
embodiment, the circuit board and LED array on all points of a
curved three-dimensional circuit board.
[0042] The invention can be formed in a foldable LED array with
multiple flat circuit boards which can be moved relative to each
other. This array can be opened and placed on a surface such as a
desk or table and can be folded and stored when not in use. A UV
opaque safety shroud with an optional door and proximity safety
switch encompassing foldable LED array can also be used.
[0043] The array of LEDs and circuit board can be made using a chip
on board manufacturing process whereby there is no plastic
encapsulation for the LED but another form of hermetic sealed cap
made of a material with better UV resistant and UV transmittance
properties than industry standard LED encapsulation. Industry
standard LED encapsulation is typically UV sensitive and reduces
the useful life of a UV LED where the LED encapsulation material
degrades under UV light conditions over time and thus has a lower
ITV transmittance over use. Portions of the hermetic seal cap (25)
may be composed of glass or quartz or other UV transparent
material. Bonding wire can be used to mount the LED chips onto the
circuit board. Chip on board mounting increases the lifetime of the
UVA LED device because of the elimination of UV degradable
encapsulating material.
[0044] UVA LED package can be mounted on the surface of the circuit
board. The UVA LED package can optionally contain a focused lens
typically found in 5 millimeter and 3 millimeter footprints on a
circuit board. The hermetically sealed TO-66 package with UVA LED
in a metal package with a UV transparent glass or quartz lens on a
circuit board can be used. A glass or quartz lens transparent to
UVA is preferred over other UV immune UV transparent material
including plastic that is not degraded by UVA light.
[0045] In yet another embodiment, various UVA LED fluorescent bulb
replacement lamp building block units referred to as UVA blocks,
with integrated power and controller and the integrated cooling
mechanisms can be used. Cooling can be implemented with fans or
heat exchangers or active cooling means or combinations of these
components. Cooling can occur across or through the array. Building
blocks may be square or round and may be stacked to build a
complete tanning device, referred to as stacked block device.
[0046] FIG. 1 shows an electrical schematic diagram for powering
the LEDs in the series connected LEDs (47) in the low voltage LED
array (22) and metallic pins (10, 12) and external LED compatible
power supply (20) responding to control from optional external
light output feedback sensor (174) and house power connector (36).
This embodiment utilizes a resistor (46) to limit the current to
the series connected LEDs (47). The series connected LEDs (47) have
multiple LEDs or a single LED depending on the voltage supplied and
number LEDs per controlled power lines (49). If the design goals of
further embodiments of the present invention requires a
controllable power line for each LED then a single LED in the
series connected LEDs (47) and LED (5) are identical. There is a
tradeoff between providing control to each LED and the cost
associated with the control circuits. Additionally, there is a
tradeoff between cost of power supply and the failure of a single
LED in an open failure mode to block the delivery of current to
multiple LEDs in the series connected LEDs (47). LED compatible
power supplies (20) designed for supplying current to individual
LEDs is more expensive because the voltage conversion is wider and
the current output is higher. The total current output from LED
compatible power supply (20) is reduced by a factor calculated as
the number of power lines (49) divided by the total number of LEDs
in the further embodiment of invention (22). Therefore, depending
upon the application and allowable failure modes, LEDs may have an
arbitrary number of LEDs in series depending on the trade-off and
application requirements. Also shown is a variable power supply
which charges capacitors (45) in a selective manner.
[0047] FIG. 2 shows an electrical schematic diagram of a LED power
control circuit that utilizes a current control (48), and an
optional capacitor (45). Current control (48) supplies current
series connected LEDs (47) via controlled power line (49) power
control line (50). Current control (48) may optionally vary the
current delivered to series connected LEDs (47) over time as the
encapsulation UV transmittance varies. Current control (48) may
optionally vary the current delivered to series connected LEDs (47)
over time to provide specific tanning patterns according to
achieving arbitrary light therapy specific results.
[0048] FIG. 3 shows an electrical schematic diagram of a LED power
control circuit that utilizes a current control (48), and a
capacitor (45), where current control (48) is attached to a single
LED (5) connected to controlled power line (49) power control line
(50).
[0049] FIG. 4 shows an electrical schematic diagram of a LED power
control circuit that utilizes said current controls (48), and an
optional said capacitors (45). Said current controls (48) supplies
current to said series connected LEDs (47) via said controlled
power lines (49) responsive to said power control lines (50) and
said external light output feedback sensor (174). The method of
calibrating each separate said current controls by selectively
turning on one said current control at a given time in order to
measure the light output from the said series connected LEDs and
calibrate each set of said series connected LEDs (47) separately.
Current control (48) may optionally vary the current delivered to
series connected LEDs (47) over time as the encapsulation UV
transmittance varies. Also shown are optional permanently mounted
connector (184) and portable connector (185) which allows said
external light output feedback sensor (174) to be moved around
within the phototherapy chamber and removed from the tanning
chamber. The light output sensor may also be fixed inside the
chamber or mounted to a translating and rotating mechanism to scan
the chamber in a mechanical and automated manner.
[0050] The use of multiple LEDs of various wavelength within a
tanning chamber can also be used. Specifically useful for tanning
are near-UV-blue LED, blue LED, blue-green LED, multi-bright LED,
solid state laser light emitting device that radiates light capable
of tanning or capable of providing light therapy of some benefit.
Also envisioned is solid state nano-structure UV-laser chip for use
in controlled multi-directional area specific tanning device
optionally associated with camera for feed-forward control for
determining exposure avoidance area and feedback control of
specific light exposure areas. Alternatively, one may use tanning
area specific mechanical translation device with laser chip based
focused light source. Another embodiment includes focused light
source utilizing LEDs on circuit board and translucent lens,
optional translucent lens, and translucent lens to create a tightly
focused light source which can be selectively powered depending on
specific areas of skin to expose to light and in particular UVA
light. Another embodiment includes focused light source utilizing
any light source lens and translucent lens, optional UV translucent
lens, and UV translucent lens to create a tightly focused UVA light
source which can be selectively controlled by light controller
depending on specific areas of skin to expose to light and in
particular UVA light. Light controller may be a blocking type
shutter or a deflecting mirror to effectively modulate the light
emitting from focused light source.
[0051] In yet another embodiment, the wavelength of the LED can be
controlled. For a given junction electric current and junction
temperature, UVA LEDs generally emit photons around a peak
wavelength in a narrow (e.g., approximately 5 nm or 10 nm) bell
curve range of wavelengths. These curves may typically be
characterized by a full width half maximum (FWHM) of about 3 nm to
20 nm. Differing LED types have differing peak wavelengths. UVA
LEDs allow fine control for generating wavelengths. That is, the
use of a plurality of the same or distinct LEDs can be used,
optionally, in combination with multiple distinct operating
conditions to independently control the emitted wavelengths. For
example, a set of LEDs of a single LED type can be controlled with
different junction currents and power duty cycles among the
individual LEDs within the set of LEDs of a single LED type in
order to broaden the spectral density of UV wavelengths emitted by
the set as a whole. In addition, multiple sets of LEDs of differing
types can be used to broaden the spectral density of UV wavelengths
to a greater extent than is possible with a set of LEDs of a single
type. The purpose of the manipulation of the LEDs is to be able to
tailor the UV wavelength for a specific individual tanning session
or specific light therapy requirements.
[0052] LEDs as a UV light source provide the capability of
controlling the wavelengths produced. LEDs of varying types produce
light at various wavelengths. By selectively controlling specific
LED types within the light therapy device sequences of light can be
applied at predetermined or arbitrary patterns with varying
wavelengths. Examples of commercially available LED types include,
but are not limited to, Cree (peak wavelengths of 405, 395 and 365
nm), Nichia (peak wavelengths of 395, 380, 375 and 365 nm), Toyoda
Gosei, Marubeni America Corporation (364-380 nm), Crystal IS in
collaboration with Palo Alto Research Center (355-365 nm).
Additional LEDs that can be used in this device include organic
light emitting devices.
[0053] Another method for controlling wavelength is based on
varying the electrical current and/or junction temperature to the
LEDs.
[0054] A single LED type at a given current and temperature will
generally produce photons that have a wavelength distribution
resembling a bell curve. Therefore, controlled current pulsing in
combination of varying the duty-cycle of the LEDs power will
control current and temperature conditions of the LED and results
in wavelength shifts that will have additional light therapy
benefits.
[0055] Generally, for a given UVA LED type, the shorter
wavelengths, within the band of producible wavelengths, results
from the lower junction currents.
[0056] An additional means to control the peak wavelength is
varying the LED ambient cooling mechanism (e.g. fans,
thermoelectric cooler, peltier effect cooling device, and
compressor based air conditioners). A UVA LED assembly control
system, comprising an analog or digital computer, a suitable
algorithm, wavelength sensors, light intensity sensors, skin
proximity sensors, and user interface for programming desired
results, can be used to calculate the required variations to the
current controllers and the duty cycle controllers and the ambient
temperature controllers in order to produce a specific peak
wavelength from a given set of UVA LEDs. The time of exposure for
any given light therapy application may vary depending on the
wavelength required and can be determined a-priori or in real time
through such a control system.
[0057] LED type detecting sensors can be used to detect the types
of LED that are present within the chamber. The use of such sensors
may reduce the hazard of programming the control system for the
wrong set of UV LED types. The detector can be mechanical in action
with specific LED assemblies having specific cutouts for indicating
type. The detector can be an RF ID system or other non-mechanical
identification system. The detector can send various standardized
controlled signals and power to the LED array to determine the
capabilities of the LED assembly for use in the programming the
control system.
[0058] Non-conducting housing for electrical connectors connecting
power and control circuits between multiple modular LED replacement
fluorescent bulb components and rotating power connectors can be
used. External light output feedback sensor can be used to increase
safety.
Nanostructure UV Light Emitting Device
[0059] In a second aspect of the invention, the present inventor
has realized that a system for a phototherapy, including skin
tanning, lupus therapy, teeth whitening, hair regrowth and
psoriasis may use a nanostructure UV light emitting device. This
allows a control of the spectral distribution (including single or
multiple peak wavelengths) of the UV light as well as provides UV
light with a narrow wavelength distribution (i.e., a narrow peak
width) or a broad wavelength distribution (i.e., a broad peak
width). The choice of a narrow or broad wavelength distribution
will depend, at least in part, on the intended application. FIGS.
5A and 5B illustrate the system (1) which contains a chamber (3)
adapted for at least one of these phototherapies and the
nanostructure UV light emitting device (4). The system (1) may be
used solely for a single phototherapy or a combination of
phototherapies depending on the need of the person being subjected
to the UV light. FIG. 5A illustrates a phototherapy system for the
prone body position, which is commonly referred to as a tanning or
a phototherapy bed. FIG. 5B illustrates a phototherapy system for
upright body positions, which is commonly referred to as a tanning
or a phototherapy booth.
[0060] The nanostructure UV light emitting device comprises at
least one of a nanoparticle and a nanowire UV light emitting
device. In some embodiments, the UV light emitting device emits
only UVA light. In other embodiments the UV light emitting device
also emits visible and/or infrared radiation in combination with UV
light. These latter embodiments may be advantageous where the light
emitting devices are intended for general purpose lighting or in
phototherapies for the treatment of conditions that respond to
visible and infrared radiation.
[0061] The term UV light includes radiation having a peak
wavelength between 160 and about 400 nm rather than visible light
having a wavelength between above about 400 and below about 700 nm.
UVA light has a peak wavelength between about 290 and about 400 nm.
The nanoparticles and nanowires emit light (i.e., radiation) with a
very narrow peak width due to their size rather than due to their
chemical composition. Thus, in contrast to conventional ceramic
phosphors which emit light with a broad peak width due to their
chemical composition and activator ion content, nanoparticles and
nanowires emit light with varying peak wavelength due to varying
their size (i.e., diameter or thickness). Furthermore, some
materials, such as silicon, which ordinarily do not emit light in
bulk form, emit light in nanoparticle form due to the nanoparticle
size. Thus, the nanoparticle or nanowire size may be selected such
that the nanoparticles or nanowires emit only UVA light, but no UVB
light. Furthermore, nanoparticle or nanowire size may be selected
such that the nanoparticles or nanowires emit only UVA-1, UVA-2
and/or UVA-3 light depending on the desired effect, since the peak
width of the emitted UV light is narrow.
[0062] Nanoparticles may be any suitable nanoparticles, such as
nanocrystals or quantum dots, having a diameter less than 100 nm,
such as a diameter of 2-20 nm, for example. For example, metal,
semiconductor, as well as metal or semiconductor oxide and/or
nitride nanoparticles may be used. Semiconductor nanoparticles
include materials from Groups IV (Si, Ge, SiC, SiGe), II-VI (CdS,
ZnS, CdSe, ZnSe, ZnTe, CdTe), IV-VI (PbS, PbSe, PbTe) or III-V
(GaAs, GaP, GaN, InP, InAs). Ternary and quaternary semiconductor
nanoparticles, such as CdZnS, CdZnSe, CdZnTe, CdZnTeSe, CdZnSSe,
GaAlAs, GaAlP, GaAlN, GaInN, GaAlAsP and GaAlInN for example, may
also be used. Ceramic or metal oxide nanoparticles may also be
used, such as silica, alumina, titania, zirconia, yttria stabilized
zirconia, yttria, ceria, spinel (for example, MgO*Al.sub.2O.sub.3)
and tantalum pentoxide, as well as other suitable ceramics having a
more complex structure, such as radiation emitting phosphors (for
example, YAG:Ce (Y.sub.3Al.sub.5O.sub.12:Ce) and various
halophosphate, phosphate, silicate, aluminate, borate and tungstate
phosphors) and scintillators (for example, LSO, BGO, YSO, etc.).
Other metal oxide nanoparticles, such as zinc oxide, indium oxide
or indium tin oxide or metal nitride nanoparticles, such as
aluminum nitride may also be used. Metal nanoparticles may be pure
metal or metal alloy nanoparticles, such as Al, Fe, Cu, Ni, Au, Ag,
Pt, Pd, Ti, V, Ta, W, Mn, Zn, Mo, Ru, Pb, Zr, etc. and alloys
thereof.
[0063] Other materials, such as Boron Carbide, Titanium Oxide
(TiO), Silicon Carbide (SiC), Antimony (Sb), Arsenic (As), Bismuth
(Bi), Cadmium (Cd), Carbon (C), Gallium (Ga), Germanium (Ge),
Indium (In), Phosphorus (P), Selenium (Se), Sulfur (S), Tellurium
(Te), Calcium (Ca), Chromium (Cr), Cobalt (Co), Magnesium (Mg),
Tantalum (Ta), Silicon Arsenide Germanium Telluride (SiAsGeTe),
Vanadium Oxide, Zinc Germanium Phosphide (ZnGeP2), Zinc Germanium
Phosphide (ZnGeP), Aluminum Antimonide (AlSb), Aluminum Arsenide
(AlAs), Aluminum Phosphide (AlP), Gallium Selenide (GaSe), Gallium
Telluride (GaTe), Indium Antimonide (InSb) and Silicon Arsenide
Telluride (SiAsTe) may also be used.
[0064] Nanoparticles may be provided in the UV light emitting
device (4) in any suitable form. For example, the nanoparticles may
be located as a solid layer or layers on a UV transparent and UV
resistant material substrate. The solid layer may also contain a UV
transparent and UV resistant binder or filler if desired.
Alternatively, the nanoparticles may be located in a suspension.
The fluid of the suspension may comprise any suitable UV
transparent fluid. Preferably, the fluid comprises a fluorocarbon
fluid, such as perfluorocarbon, chlorofluorocarbon or
hydrofluorocarbon fluid. For example, the fluid may comprise
1,1,1,2 tetrafluoroethane also known as R134A or perfluorocarbon
fluids sold under the PPx series from F2 Chemicals Ltd. in Lea
Town, U.K., such as the PP6 perfluorocarbon fluid. The R134A fluid
is provided under elevated pressure to remain in the liquid state
at room temperature. Other fluids which are liquid at atmospheric
pressure at room temperature may also be used. If the nanoparticles
are located in a suspension, then the suspension is located in a
sealed vessel or tube made of a UV transparent and UV resistant
material. If desired, the device (4) may also contain a pump or
vibrator which maintains the suspension under turbulent flow to
prevent the nanoparticles from settling on the surface of the
vessel.
[0065] Nanowires may be any suitable nanowires having a thickness
(i.e., diameter) of less than 150 nm, such as a thickness of 70-100
nm, for example. The nanowires may comprise any suitable material,
such as metal oxide material. For example, zinc oxide, indium oxide
and indium tin oxide nanowires may be used. Any suitable length of
nanowires may be used.
[0066] The system (1) further preferably comprises a UV excitation
source (7). The source (7) is positioned to provide UV excitation
radiation of a first peak wavelength onto the nanostructure UV
light emitting device (4) to cause the nanostructure UV light
emitting device to emit UVA light having a second UVA peak
wavelength longer than the first peak wavelength. Any suitable UV
excitation source may be used.
[0067] In one preferred embodiment shown in FIG. 6, the UV
excitation source (7) comprises a gas vessel comprising a gas which
is adapted to emit the UV excitation radiation in response to a
stimulus. For example, the source may be a gas lamp tube filled
with a gas such as Ar or Hg which emits UV radiation when a voltage
is applied to the electrodes (9) of the gas tube. The UV light
emitting device (4) in this embodiment comprises at least one layer
of nanoparticles coated on an inner surface of at least one UV
light transparent wall of the gas vessel or tube (7). In other
words, the conventional phosphor in a fluorescent lamp (7) is
replaced with or combined with one or more layers of nanoparticles
which emit UVA light in response to UV excitation radiation emitted
by the gas. In this case, rather than using an expensive UV
emitting lamp, a cheap germicidal or white light emitting lamp may
be used instead, but with replacing the white light emitting
phosphor with UVA light emitting nanoparticles. Preferably plural
layers of nanoparticles are coated on the inner surface of the gas
tube or vessel (7) to prevent the UVB or UVC radiation emitted by
the gas, such as 254 nm UVC radiation, from being incident on the
skin of a person in the phototherapy chamber (3). The UV exciting
radiation from the gas in vessel (7) is incident on the
nanoparticles (4), which emit UVA light in response to the incident
radiation. The nanoparticles (4) block the UV excitation radiation,
such as UVC radiation, from exiting the vessel or tube (7).
Alternatively, another UV emitting LED could be used as an
excitation source.
[0068] In another preferred embodiment shown in FIG. 7, the UV
excitation source (7) comprises any suitable UV lamp which
optionally contains a UV emitting phosphor (6) on its inner walls.
The UV light emitting device (4) comprises at least one layer of
nanoparticles coated on an outer surface of the UV lamp (7). The UV
exciting radiation from the lamp from the lamp (7) is incident on
the nanoparticles (4), which emit UVA light in response to the
incident radiation.
[0069] Various other UV excitation sources (7) may be used. For
example, the UV excitation source may comprise a focusing lens
which focuses solar radiation onto the UV light emitting device.
Furthermore, while an optical UV excitation source (7) is
preferred, in an alternative aspect of the invention, an electrical
excitation source may be used instead. In this case, the
nanoparticles or nanowires (4) are located between two electrodes.
At least one electrode is preferably made of an electrically
conductive and UV transparent material, such as indium oxide, tin
oxide or indium tin oxide (ITO). When a voltage is applied between
the electrodes, the voltage causes the nanoparticles or nanowires
to emit UV light.
[0070] It should be noted that the nanoparticles or nanowires (4)
do not have to be placed directly on the UV excitation source (7).
The nanoparticles or nanowires may be located on a separate
substrate, such as a UV transparent substrate, or in a separate
suspension in a vessel, which is located between the UV excitation
radiation source (7) and the portion of the chamber (3) which
houses the person undergoing phototherapy.
[0071] In a third embodiment shown in FIG. 8A, the UV light
emitting device (4) comprises a plurality of layers of
nanoparticles or nanowires arranged in a direction extending from
the UV excitation radiation source (7) to the portion of the
chamber (3) which houses the person undergoing phototherapy. The
nanoparticles or nanowires in each layer emit radiation having a
different peak wavelength from the nanoparticles or nanowires in
other layers. Preferably, the peak wavelength of the UV radiation
emitted by the nanoparticles or nanowires increases in each
subsequent layer in the direction from the UV excitation source (7)
to the portion of the chamber (3) which houses the person
undergoing phototherapy. In other words, the nanoparticles or
nanowires in each layer located closer to the person's skin (i.e.,
farther from the UV excitation source (7)) emit radiation of a
longer wavelength that those in another layer located farther from
the person's skin (i.e., closer to the UV excitation source (7)).
This allows the stacked layers of nanoparticles or nanowires to
gradually or stepwise upconvert the UVB and/or UVC radiation
emitted by the UV excitation radiation source (7) to desired UVA
radiation. There may be two or more layers of nanoparticles or
nanowires.
[0072] For example, as shown in FIG. 8A, the UV excitation
radiation source (7) may emit 254 nm peak UVC radiation. A first
layer (110) of first nanoparticles or nanowires is located proximal
to the UV excitation source (7). The first nanoparticles or
nanowires emit UV light of a third peak wavelength, such as 315-340
nm, which is longer than the 254 nm peak wavelength, when
irradiated with the UV excitation radiation from source (7). A
second layer (130) of second nanoparticles or nanowires is located
distal from the UV excitation source, such that the first layer
(110) is located between the second layer (130) and the UV
excitation source (7). The second nanoparticles or nanowires emit
UV light of the second peak wavelength longer than the third peak
wavelength when irradiated with the UV light from the nanoparticles
or nanowires of the first layer (110). For example, the
nanoparticles or nanowires of the second layer (130) may emit UVA-1
radiation having a peak wavelength of 345-355 nm or 395-405 nm when
irradiated with UVA-2 or UVA-3 radiation from the first layer
(110). Additional layers of nanoparticles or nanowires may be
located between layers (110) and (130) to make the radiation
wavelength upconversion (i.e., energy down conversion) even more
gradual.
[0073] Layers (110), (130) may be formed directly on each other
with the UV excitation source (7) acting as a substrate.
Alternatively, each layer (110), (130) may be spaced apart from the
adjacent layer and each layer may be formed on a separate UV
transparent substrate, such as glass, plastic or quartz substrate,
or in a separate solution holding vessel.
[0074] FIG. 8B illustrates an alternative aspect of the third
embodiment. In this aspect, three layers of nanoparticles or
nanowires (110), (120) and (130) are arranged in a clam-shell type
housing (250) comprising an opaque body. The UV excitation source
(7) is located in the interior portion of the housing (250). A
mirror (270) shields the back side of the source (7). The first
layer (110) of nanoparticles or nanowires is located opposite to
the source (7) and mirror (270), such that UV excitation radiation
from source (7) and mirror (270) is incident on the first layer
(110). The second layer (120) of nanoparticles or nanowires emits
UV light having a peak wavelength between those of the first (110)
and third (130) layers. The second layer (120) is positioned in the
housing to receive UV light from the first layer (110) and to emit
UV light of a longer wavelength onto the third layer (130). The
third layer (130) is positioned to receive UV light from the second
layer (120) and to emit UV light of an even longer wavelength out
of the housing through a lens (290) and through an optional long
wavelength filter, which blocks shorter wavelength UV light from
the source (7), first layer (110) and second layer (120) from
exiting the housing (250). If desired, a light absorbing surface
may be located behind the layers (110), (120) and (130). It should
be noted that the term "layer" as used herein includes a
nanoparticle or nanowire solid layer as well as a nanoparticle
suspension located in a vessel. By using the clam-shell shaped
housing (250), UV light of one or more desired wavelengths from
layers (110), (120) and/or (130) exits the housing (250). In should
also be noted, that although this clam-shell design for a
nanoparticle-based light source is described primarily in
conjunction with various phototherapies, this device may also be
employed for general purpose lighting.
[0075] In a fourth embodiment of the present invention shown in
FIG. 9, an optical filter (150) is located between the UV
excitation source (7) and the UV light emitting device (4). The
filter (150) is transparent to the shorter wavelength UV excitation
radiation from source (7). However, the filter (150) reflects UV
light of a longer peak wavelength emitted by the UV light emitting
device (4). The filter (150) may be a holographic filter or any
other suitable filter having the above described property. This
configuration is advantageous when nanoparticles are used as the
light emitting device (4). The nanoparticles emit UV light in all
directions. However, the filter (150) reflects UV light emitted
toward the source (7) back in the direction of the portion of the
chamber (3) in which the person is to be located.
[0076] The fifth embodiment is a combination of the third and
fourth embodiments. As shown in FIG. 10, the UV light emitting
device (4) comprises a plurality of layers (110), (130) of
nanoparticles or nanowires arranged in a direction extending from
the UV excitation radiation source (7) to the portion of the
chamber (3) which houses the person undergoing phototherapy. The
nanoparticles or nanowires in each layer (110), (130) emit
radiation having a different peak wavelength from the nanoparticles
or nanowires in other layers. The peak wavelength of the UV
radiation emitted by the nanoparticles or nanowires increases in
each subsequent layer in the direction from the excitation
radiation source (7) to the portion of the chamber (3) which houses
the person undergoing phototherapy. A filter (170) is located
between adjacent layers of nanoparticles or nanowires. The filter
(170) is transparent to the shorter wavelength UV light from the
layer (110) proximal to the UV excitation source (7). However, the
filter (170) reflects UV light of a longer peak wavelength emitted
by layer (130) distal from the UV excitation source (7). If the
device (4) contains more than three layers of nanoparticles or
nanowires, then a different filter may be located between each
pairs of layers.
[0077] In a sixth embodiment, the nanoparticles or nanowires are
arranged in pixels as shown in FIG. 11. The nanoparticles or
nanowires in each pixel can be separately activated by a dedicated
UV excitation radiation source or by dedicated electrodes to
selectively tan or treat a desired portion of skin on the person
undergoing phototherapy. In one aspect of the sixth embodiment, the
UV light emitting device (4) includes a first set of pixels (190)
of first nanoparticles or nanowires. The first nanoparticles or
nanowires are adapted to emit UV light having a predetermined first
peak wavelength. The device (4) also includes a second set of
pixels (210) of second nanoparticles or nanowires. The second
nanoparticles or nanowires emit UV light of the second peak
wavelength longer than the first peak wavelength. If desired,
additional sets of pixels may be provided. Pixels of the first set
of pixels (190) are interspersed with pixels of the second set of
pixels (210).
[0078] All pixels may be turned on at once to provide UV light
having a plurality of different peak wavelengths or one set of
pixels may be selectively activated while the other sets remain
turned off. In this case, the peak wavelength of the UV light may
be selectively tailored for each individual based on the desired
darkness of the tan, the individual's skin color or a selection of
a particular wavelengths to treat a particular condition during
phototherapy.
[0079] In a seventh embodiment, the system (1) contains the UV
light emitting device (4) with exchangeable nanoparticles or
nanowires to vary the peak emission wavelength of the device (4).
For example, if the nanoparticles are located in a suspension in a
sealed vessel, then the vessel may be opened and the suspension
replaced by another suspension having nanoparticles which emit
light of a different wavelength from the nanoparticles in the
original suspension. Preferably, the vessel comprises non-stick
surfaces to prevent nanoparticle adhesion. Alternatively, the
entire vessel housing the suspension may be removed from the system
and replaced with another vessel containing a different suspension
of different nanoparticles which emit light of a different peak
wavelength than the nanoparticles of the original suspension. If
the nanoparticles or nanowires are coated as a solid layer on a
substrate or substrates, then the substrate or substrate may be
easily removable from the system to allow the system operator to
insert a substrate or substrates containing nanoparticles or
nanowires which emit light of a desired peak wavelength into the
system (1).
[0080] A method of operating the system (1) for phototherapy,
including skin tanning, lupus therapy, teeth whitening, hair
regrowth or psoriasis therapies, includes providing UVA light from
a nanostructure UV light emitting device (4) onto a skin of a human
subject who is located in a chamber (3) adapted for at least one of
these phototherapies in order to provide phototherapy for the
skin.
[0081] The method also includes providing UV excitation radiation
of a first peak wavelength from a UV excitation source (7) to the
UV light emitting device (4). The method also includes emitting the
UVA light having a second UVA peak wavelength longer than the first
peak wavelength from the UV light emitting device (4) in response
to the provided UV excitation radiation.
[0082] In an eighth embodiment, blue light having a wavelength of
about 400 to about 415 nm, such as about 405 nm is used instead of
UV light. Light of this wavelength is sometimes called violet or
purple rather than blue. Any suitable blue or violet light emitting
device (4) which emits light of this wavelength may be used,
including a lamp, a light emitting diode, nanoparticle or nanowire
containing device (4). The light emitting diode, nanoparticles and
nanowires are preferred because they have a narrower emission peak
width. For light emitting diodes, blue light emitting diodes based
on GaN, SiC or ZnSe semiconductor materials may be used. Tanning
with light in the 400-415 nm wavelength range may provide a longer
lasting tan than tanning with UV light. Preferably but not
necessarily, the light emitting device emits light having
substantially no wavelengths outside the about 400 nm to the about
415 nm range, such as emitting less than 1% of light having
wavelengths outside the about 400 nm to the about 415 nm range. The
device (4) of this embodiment may be used in combination with the
configuration(s) of the other embodiments described herein.
Illustrative Device Designs
[0083] Both the UV LED-based systems, devices and chambers and the
nanostructure-based systems, devices and chambers may include a
variety of components and may have a variety of geometries and
designs, based on the particular therapy being delivered. By way of
non-limiting examples, embodiments of systems, devices and chambers
for both types of UV sources (i.e., for both the UV LED-based
systems and the nanostructure-based systems) are provided here.
[0084] In these systems, devices and chambers, various wavelength
LEDs or nanostructure UV light emitting devices can be used
separately or in combination and may be selected and controlled for
use in phototherapies and as multi-wavelength light bulbs for
general purpose lighting. The LEDs and/or nanostructure UV light
emitting devices may be used in combination with other light
sources that emit in the UV, visible (VIS) or infrared (IR) to
provide a desired radiation spectrum. In one example, the LEDs
and/or nanostructure UV light emitting devices may be combined with
one or more conventional light bulbs in a single system. In other
examples, UVA can be used in combination with yellow, orange,
green, blue, red, violet, IR, fluorescent, and/or UVC, as modular
or fixed designs, in combination or separate. Bulbs capable of
producing various wavelengths can be combined in arbitrary patterns
to produce arbitrary light therapy devices. Further, the wavelength
produced by any one UV source can be varied.
[0085] The chambers incorporating the UV sources can be a booth or
bed and can be enclosed or open. The chamber can be composed of a
variety of materials including UV opaque film or UV opaque solid
walls to control the exposure direction of the light. The UV
sources (i.e., LEDs or nanostructure devices) can be directed to
expose light within the chamber and can be on the same or on
independent controls. In general, the internal surface of the
chamber walls will be UV reflective while the external surface and
the wall itself will be UV opaque.
[0086] For example, height dependent chambers with light saving
feature sections of controllable UV sources can selectively be
turned off where the person in the phototherapy chamber does not
require all of the controllable light sources (including UVA LEDs
and UVA nanostructure emitters) turned on because of height, or
because of the desire to treat (or not treat) specific parts of the
body. For example, the light sources can be arranged and
selectively powered to avoid treatment of pre-cancer sites or
moles. A UV source controller may be present in the chamber (or
outside the chamber) to adjust the height, pattern, brightness and
other features of the phototherapy system. The controller has a
manual controller input, an automatic height sensor input, or both.
The controller can adjust brightness and duration of exposure based
on the temperature of the devices with optional temperature sensor
input. The controller can vary the pattern accordingly and indicate
to the user the best direction to stand and in what position the
extremities should be in order to have the best solution for
obtaining the desired results if, for example, the chamber does not
have a full 360 degrees of phototherapy. Alternatively, the height
controller may be an external component to facilitate a full 360
degree of controllable UV source array. Additionally, one may
include a master controller and master-slave communication device
and slave-slave communication device.
[0087] A person in the upright or a person in the prone position
can be exposed to a directionally controllable focused light source
controlled either by controllable mirrors or controlled by
phototherapy area specific mechanical translation device of focused
light source or controlled by a combination of both methods to
effectively treat only the desired areas. This allows blemished
problem skin or pre-cancerous skin problem to remain unexposed to
the focus light.
[0088] A history of the use of the phototherapy systems can be
stored and later accessed in order to improve the effectiveness of
the control system. Historical information can include one or more
of the following: number of sessions, session type, duty cycles,
electric current levels, power duty cycles, ambient temperatures,
UV exposure patterns and other UV source type specific information.
Information can also be stored in a remote location and a
serialized coded key device (e.g. a memory chip, ROM, battery
backed RAM, or optical memory) will provide the control system with
a means of look-up for prior history of the phototherapy system.
The history of use of a particular phototherapy system can be used
in the control systems to calculate wavelength and exposure times
for a desired light therapy session. This may prove to be a very
desirable feature in light of the importance of keeping an accurate
patient treatment records.
[0089] It is noted that personal slippers can improve health
conditions on the surface of the device when shared, by reducing
germ contamination between individuals. The personal slippers can
be UV translucent or UV opaque depending on choice of person
undergoing phototherapy.
[0090] Preferably, the person undergoing phototherapy can be
equipped with radio identification, UV opaque protective eye-wear
(with an optional safety feature to indicate that the eyewear is
worn) and user interface. The user communication and safety control
system can be accessible from the inside and/or outside of the
chamber containing receiver for UV opaque protective eye-wear with
an identification device used to indicate the presence of the UV
opaque protective eye wear within the chamber. The identification
device may be wireless or a wired communication device.
[0091] The form factors for incorporating the UV sources can be
optionally contoured to fit or conform to the body or body part of
the individual user. For example, the form may be a face tanning
system incorporating LEDs or nanostructure-based emitters and
circuit board. Such a face tanning system may in the form of a face
mask (optionally extending to the neck area or below), with
optional ports for the eyes, nose and/or mouth and can incorporate
one or more optional fans at the edge(s) of the mask for
ventilation and cooling purposes, optional audio speakers for
listening to music or environmental sounds with either stereo or
quadraphonic audio input and/or microphone for verbal
communications with optional telephonic capabilities, microphone
input for further communications capability. Additionally, the mask
can be characterized by an external UV source compatible power
supply with optional timer control, power switch, house power
connector and/or external battery connector, an optional
programming keypad for entering user codes and lockout features,
key-lock, proximity switch to ensure a proper fit of the mask by
controlling the closing of the mask and the operation of the hinge
attached to UV opaque face shield. A circuit board which has
multiple current controls controlled by signals from control lines,
and has connections to power lines, connections to the UV source
and connections to power source and current return drain on pins.
In this embodiment, the pins can be flexible.
[0092] In another embodiment, the form encompasses the full head
and neck phototherapy system. Again, as above, additional
components can include audio speakers, external UV source
compatible power supply and house power connector. LEDs or
nanostructure-based emitters may be selectively powered to provide
specific areas of phototherapy.
[0093] Alternatively, a mechanical translating phototherapy system
that has a spatial translating UV source loop (or loops) that
encircle(s) the user has the advantage of requiring fewer bulbs to
treat the same area of skin over a longer period of time. This
embodiment has a reduced cost because fewer UVA LEDs or
nanostructure UV light emitting devices are required to produce the
desired therapy. Either the system (or loop) moves longitudinally
with respect to the client, or the client may moves parallel with
the axis of the loop, or both. The movement may be manual or it may
be power assisted in a manual or automatic control manner. This
system can accommodate a standing user or a prone user. The loop(s)
can be mounted on a wall or ceiling-mounted track, for example, via
a hinge to allow clients to enter and exit the chamber. The UV
translucent bed may be acrylic. Translating UV source loops may be
comprised of combinations of controllable UVA LEDs or nanostructure
UV light emitting devices to be selectively powered depending on
position and area requiring tan.
[0094] In any UV light exposure application it is recommended for
people being exposed to use UV opaque protective eye-wear, and it
is recommended for people being exposed to shut the eyelids as much
as possible in order to minimize exposure of the retina to UV. It
is important to maintain strict observation of the requirement for
UV opaque protective eye-wear during operation of phototherapy
equipment. Therefore, in one embodiment, special control circuits
can be incorporated into the phototherapy systems to prevent
powering the UV sources when UV opaque UV opaque protective
eye-wear is absent. In addition, training in use of phototherapy
equipment is highly recommended.
[0095] Some embodiments of the phototherapy devices incorporate
combinations of sensors and communication equipment into the
phototherapy device to determine if the user has UV opaque
protective eye-wear present and worn correctly before allowing the
phototherapy system to start emitting UV radiation. This reliable
personal phototherapy device incorporates special safety features
that identify people and do not allow for over-exposure of any user
to UV light over a given time frame. This reliable personal
phototherapy device interfaces to a computer terminal with
associated software logic and with associated input and output
control ports, to provide information such as length of therapy for
a each unique user and to provide historical records of user
specific phototherapy activities and accounting details.
[0096] In an example, a person with UV opaque protective eye-wear
can be exposed to light therapy in the presence of multiple types
of light sources which includes a UVA LED array and/or a
nanostructure UV light emitting device alone or in combination with
the prior art UV light sources such as high pressure and low
pressure fluorescent bulb within a phototherapy chamber. The
chamber can optionally possess one or more UV opaque walls, a UV
opaque phototherapy chamber door, a ventilation system, a cooling
system, a safety switch connected to shut-off controller and/or
system controller, a controller communication device, a high
voltage ballast (for use with first embodiment of invention or
fluorescent bulb and with low voltage LED power supply), and/or an
external light output feedback sensor, for use with alternate low
voltage embodiment of the present invention and calibration
requirements.
[0097] The phototherapy systems and devices can be used in
conjunction with a payment system associated with, for example, a
rental of phototherapy chamber, commercial sales and rental store
and of the phototherapy systems as in indoor-phototherapy salons.
Battery backup power supplies can be provided for operation of
phototherapy equipment and control systems during momentary power
outages. A computer based control and communications system for
operating the phototherapy salon and associated controllable
phototherapy equipment and personal services and communicating with
other associated phototherapy salons and home offices via
communications lines or via wireless communication system can be
incorporated. The communications system may also be adapted to
identify and report equipment malfunctions or maintenance needs to
a remote location.
[0098] As an alternative to phototherapy beds or booths, in some
embodiments of the invention, the UV sources are incorporated into
articles of clothing, and into cloth, and into flexible forms, and
into rigid forms that allow for home phototherapy systems and for
personal phototherapy systems such as phototherapy jackets,
phototherapy pants, phototherapy suits, phototherapy bags or sacs,
phototherapy blankets and phototherapy rooms.
[0099] Personal phototherapy systems can be shared by different
people at different times. If a personal phototherapy system is
shared, it is desirable to have a set of removable UV-translucent
garment or liner capable of being washed. A personal phototherapy
system that is cleaned in an efficient manner between uses is
desirable. A personal phototherapy system with the ability to be
cleaned is desirable whether shared or un-shared.
[0100] UV light has surface sterilization effects and therefore a
personal phototherapy system will to some degree be self-cleaning
with regard to certain undesirable bacteria such as mold and
mildew. Additionally, UVB and UVC light sources may be incorporated
into a personal phototherapy device to produce a higher degree of
sterilization when operated in a special cleaning mode without the
presence of a user.
[0101] The clothing may be in the form of full or partial body
phototherapy apparel. For example, apparel can avoid golfer's tan
by allowing full body exposure to the light while still providing
privacy where the outer layer of the apparel is opaque. The apparel
can be made of material that contains a UV blocking or reflecting
component positioned to keep the UV light in the apparel. The
apparel can be lined with a removable layer or a first inner layer
can be a layer in between the outer and inner layer that contains
the UV sources and circuit board and the circuitry and cooling and
controlling components. A UV translucent inner layer comes in
contact with the client. For sanitary reasons the inner layer is
preferably used exclusively by a single client and/or can be
washed. This inner fabric will be completely or partially
transparent to UV light. The inner fabric will also be able to
diffuse the UV light in a manner that will allow the client to
receive a consistent tan over the surface of the body. Controls
selectively control the UV sources to be energized in a desired
pattern. This desired pattern may be saved and recalled
automatically through the registration and control system connected
to controlled power lines and a control line. A UV opaque zipper or
other fastener can be used to get into the full body tanning
apparel and limit the amount of UV radiation emitted. This
embodiment of the invention will allow tanning slowly over a period
of time preferably while sleeping. Slow tanning may be less
stressful on the skin. Tanning apparel and sleeping bags may be
used to slow down the tanning process, reduce the required light
flux and can tan in a comfortable environment. Cooling systems can
also be controlled by control system through control wires.
External UV source compatible power supplies and house power
connectors can be incorporated into the device.
[0102] The apparel can have a layer of partially or fully UV opaque
material, inside the inner layer of the full body tanning apparel
next to the body covering parts of the client that require no UV
exposure. Alternatively, the client can attach a patch to the skin
to protect it from UV exposure. The use of partially or fully UV
opaque filters results in a controlled tanning pattern without the
need for granular control of the UV source.
[0103] Of course, multiple connections and controllers over various
parts of the full body phototherapy apparel, can be used rather
than a single controller or connector, whether the chamber is made
of fabric, is flexible or rigid.
[0104] Modular selective phototherapy apparel allows selectable
patterns for phototherapy. Modular and selective phototherapy is
useful in medical cases such as a person with a medical skin
condition (e.g., psoriasis) that requires a prescribed light
therapy as directed by a physician or other medical person or
medical therapist. In this embodiment, the module connectors are
connected to a common controller at the phototherapy apparel edge.
An alternate design uses external connectors. Multiple
two-dimensional components connected into three-dimensional
assemblies are useful building block components for modular
phototherapy apparel.
[0105] Various shapes of modular phototherapy apparel can be
readily envisioned, including, for example, a torso, leg, foot,
arm, scalp, pants, shirt and hat. The shapes can be
inter-connectable pieces of phototherapy apparel to build a
complete or partial modular phototherapy suit. Arbitrary numbers of
connector, arbitrary types of connectors, arbitrary shapes of
components, and arbitrary materials of components, and arbitrary
orientations of connectors allow for arbitrary phototherapy devices
to be constructed.
[0106] A curved three-dimensional modular fabric component for
completing power and control signal connections between
phototherapy apparel components, with two sides having male style
connector power pins and male style communications connector and
two sides with female style hollow power connectors and female
style communications connector. Alternatively, a curved
three-dimensional modular fabric component with one, two or three
sets of male connectors which would represent an end component or
corner of the fabric can be made. Not shown is the curved
three-dimensional modular fabric component with one, two or three
sets of female connector which would represent an end component in
the fabric.
[0107] Two-dimensional components used to build three-dimensional
assemblies connections from one segment of clothing to another for
power and control signals can be designed to keep electromagnetic
interference to a minimum.
[0108] A three-dimensional modular fabric component, such as a box
component, for completing power and control signal connections
between phototherapy apparel components, with two sides having male
style connector power pins and male style communications connectors
and two sides with female style hollow power connectors and female
style communications connectors can be conveniently used. One or
more of each component can be used. Not shown is one side with
quartz or other UV translucent material to allow UV light to reach
the skin. Arbitrary numbers of connector, arbitrary types of
connectors, arbitrary shapes of components, and arbitrary materials
of components, and arbitrary orientations of connectors allow for
arbitrary tanning devices to be constructed.
Illustrative Phototherapy Designs and Parameters
[0109] The present discussion is provided to illustrate various
non-limiting system designs and parameters that may be adopted for
carrying out some specific exemplary types of phototherapies in
accordance with the present invention.
[0110] It should be noted that the systems and devices of the
present invention are particularly well suited for use in
phototherapies generally, and the phototherapies listed below in
particular, because they make it possible to adjust the overall,
combined, resulting spectral distribution which may be composed of
one or more component spectral distributions, each of which may be
programmatically controlled to vary over time as needed during a
phototherapy session (e.g., during the treatment of lupus). In
addition, the present system and devices provide either continuous
spectral distributions or spectral distributions having discrete
atomic spectral lines at selected, well-defined locations. Using
the latter embodiment, the location of the lines may be selected to
provide more intense phototherapy where it is needed or wanted.
This is in contrast to mercury vapor lamps and to phosphor
converted fluorescent mercury vapor lamps which inevitably emit
some discrete atomic spectral lines at naturally occurring, fixed
(i.e., not selectable) locations. Therefore, using these lamps it
is not possible to carefully tailor the location of the regions of
intense phototherapy.
Lupus Phototherapy:
[0111] Both the UV LED and nanostructure-based systems and devices
provided herein may be used in the treatment of lupus. For example,
the invention provides methods of treatment wherein UV light
provided from at least one light emitting diode or from a
nanostructure UV light emitting device, of the type described
herein, is directed onto the skin of a human subject having lupus.
Typically, the systems and devices designed for lupus phototherapy
will be tailored to expose the entire patient, or a significant
portion of the patient to the UV light.
[0112] The treatment of lupus with UV light generated by mercury
vapor based light sources and long wavelength (UVA-1) passing light
filters is known and is described in "Reversal of brain dysfunction
with UV-A1 irradiation in a patient with systemic lupus," Lupus.
2003; 12(6):479-82; "Ultraviolet-A1 (340-400 nm) irradiation
therapy in systemic lupus erythematosus," Lupus. 1996 August;
5(4):269-74; "Longterm ultraviolet-A1 irradiation therapy in
systemic lupus erythematosus," J Rheumatol. 1997 June;
24(6):1072-4; "Ultraviolet A1 (340-400 nm) irradiation and systemic
lupus erythematosus," J Investig Dermatol Symp Proc. 1999
September; 4(1):79-84. Review; "Ultraviolet-A1 irradiation
decreases clinical disease activity and autoantibodies in patients
with systemic lupus erythematosus," Clin Exp Rheumatol. 1994
March-April; 12(2):129-35, the entire disclosures of which are
incorporated herein by reference. Suitable phototherapy treatment
conditions, including wavelengths, intensities and exposure times
are described in these references. In some preferred embodiments,
the UV radiation having a wavelength of about 400 to about 340 nm
is employed.
Psoriasis Phototherapy:
[0113] Both the UV LED and nanostructure-based systems and devices
provided herein may be used in the treatment of psoriasis. For
example, the invention provides methods of treatment wherein UV
light provided from at least one light emitting diode or from a
nanostructure UV light emitting device, of the type described
herein, is directed onto the skin of a human subject having
psoriasis.
[0114] Desirable phototherapy treatment parameters for psoriasis
include exposure to a narrow band emission peaking at or between
312 nm and 311 nm. Because the nanostructure UV light emitting
devices are capable, through various manufacturing processes, of
providing highly controlled spectral distribution emission bands,
including broad bands and very narrow bands which can range from
widths of 200 nm to vanishingly narrow, nearly discrete bands they
are well suited for this application. Therefore the nanostructure
UV light emitting devices can be designed to deliver a narrow band
of light peaking between 312 nm and 311 nm. This represents an
improvement over psoriasis phototherapies that use mercury vapor
lamps, because such lamps are only capable of delivering a discrete
spectral line at 313 nm, but in the ranges with peaks between 311
nm or 312 nm, which are the preferred wavelengths for psoriasis
phototherapy.
[0115] In these embodiments the UV chambers used in the
phototherapy systems and devices may be tailored to conform to and
provide UV irradiation to only that part of the body suffering from
the condition. For example, the chambers may be tailored to
irradiate only an arm, a leg or the face of the subject.
[0116] UV phototherapy for the treatment of psoriasis is described
in U.S. Pat. No. 6,436,127, the entire disclosure of which is
incorporated hereby reference. This reference includes additional
descriptions of suitable phototherapy parameters, such as
wavelength ranges, power and duration.
Hair Growth Phototherapy:
[0117] Both the UV LED and nanostructure-based systems and devices
provided herein may be used to promote hair growth or regrowth on a
human subject. For example, the invention provides methods of
treatment wherein UV light provided from at least one light
emitting diode or from a nanostructure UV light emitting device, of
the type described herein, is directed onto the skin of a human
subject desiring hair growth or regrowth. The UV light may be used
in conjunction with a hair growth assistance chemical, such as
minoxodil which undergoes a hair growth-stimulating photochemical
reaction when exposed to the UV radiation.
[0118] In these embodiments the UV chambers used in the
phototherapy systems and devices may be tailored to conform to and
provide UV irradiation to only that part of the body where hair
growth of regrowth is desired. For example, the chambers may be
tailored to irradiate only the scalp of a subject. In one such
embodiment, the chamber may take on the form of apparel, such as a
helmet or hat, that the subject can wear as a personal phototherapy
device.
[0119] By way of illustration only, one specific example of a
system that may be used to stimulate hair growth is described as
follows. This embodiment incorporates an LED based hair growth
assistance means, wherein said LED based hair growth assistance
means is comprised of combinations of components including but not
limited to a hair growth assistance light source means (typically a
plurality of LEDs with one or more wavelength including but not
limited to UV light emitting diodes with wavelength of 395 nm), a
light mixing means (when more than a single wavelength LED is
incorporated), a hair growth assistance enclosure means, a hair
growth assistance fit detection means (including proximity safety
switches on said hair growth assistance enclosure means and on said
UV eyewear protection means to determine proper fit of both the UV
protection eyewear and the hair growth assistance enclosure), a
hair growth assistance power supply means (low voltage with at
least one national certification or international certifications,
for example in the USA a UL approved rating), a hair growth
assistance electric current overdrive control means (for reducing
the required number of LEDs), a hair growth assistance light
measurement means (used to determine imminent failures or feedback
to current control means in the case of reduced luminous power over
time), a hair growth assistance memory (to determine life and usage
patterns), a hair growth assistance microcontroller (e.g. MC68CH11
with ROM, RAM and FLASH), hair growth assistance microcontroller
operating programs, a hair growth assistance active junction
temperature environmental control means, a hair growth assistance
light source cooling means, a hair growth assistance control means
(with operation lockout features), a hair growth assistance
communications means (for connecting proximity sensors), a hair
growth assistance timer means (with maximums and responsive to
logic in the case of a poor fit restart of a single session), a
battery (for portable operation) useful for the purpose of
stimulating hair growth with reduced hazards. Said UV LED includes
but is not limited to UV light emitting diodes, wherein UV light
emitting diode includes but is not limited to UV-395-TO92
manufactured by Bivar Corp, Irvine, Calif., USA, to NSHU550A
manufactured by Nichia USA, and to LC503MUV1-30Q a 5 mm t-1 3/4
package from Marktech Optoelectronics, Menands, N.Y., USA.
Teeth Whitening Phototherapy:
[0120] Both the UV LED and nanostructure-based systems and devices
provided herein may be used to whiten teeth. For example, the
invention provides methods of treatment wherein a teeth whitening
agent, such as carbamide peroxide, is applied to a subject's teeth
and UV light provided from at least one light emitting diode or
from a nanostructure UV light emitting device, of the type
described herein, is directed onto the whitening agent-coated
teeth. This teeth whitening phototherapy could be done by a dentist
or in a tanning salon. UV to blue light having wavelengths of about
340 nm to about 700 nm, and specifically about 395 to about 410 are
well suited for use in teeth whitening phototherapies.
[0121] In these embodiments the phototherapy systems and devices
may be tailored to conform to and provide UV irradiation to the
teeth of the patient. In one such embodiment, the device may take
on the form of a mouth guard or dental retainer, that the subject
can wear as a personal phototherapy device. Such devices would
irradiate the teeth from inside the mouth, preferably from the
direction of the lips toward the teeth. Alternatively, the device
may include a one or more external UV LEDs or nanostructure UV
light emitting device and a brace for holding the subjects lips
and/or tongue away from the teeth in order to avoid unnecessary
exposure of the lips and tongue to the radiation. Such braces are
well known in the dental arts.
[0122] UV phototherapy for teeth whitening is described in U.S.
Patent Application Publication No. 2004/0076926, issued to
Baughman, the entire disclosure of which is incorporated by
reference. This reference describes suitable phototherapy
parameters, including wavelengths, power and duration, as well as
mouthpieces that may be adapted to provide internal UV phototherapy
devices in accordance with the present invention.
[0123] By way of illustration only, one specific example of a
system that may be used to whiten teeth is described as follows.
This embodiment incorporates an LED based teeth whitener means,
wherein said LED based teeth whitener means is comprised of
combinations of components including but not limited to a teeth
whitener light source means (typically a plurality of LEDs with one
or more wavelength including but not limited to UV light emitting
diodes with wavelength of 395 nm), a light mixing means (when more
than a single wavelength LED is incorporated), a teeth whitener
enclosure means (with substantially opaque walls and with
translucent interior and with one or more UV translucent openings
arranged so as to protect skin and gums while exposing teeth to
phototherapy), a teeth whitener fit detection means (including
proximity safety switches on said teeth whitener enclosure means
and on said UV eyewear protection means to determine proper fit of
both the UV protection eyewear and the teeth whitener enclosure), a
teeth whitener power supply means (low voltage with at least one
national certification or international certifications, for example
in the USA a UL approved rating), a teeth whitener electric current
overdrive control means (for reducing the required number of LEDs),
a teeth whitener light measurement means (used to determine
imminent failures or feedback to current control means in the case
of reduced luminous power over time), a teeth whitener memory (to
determine life and usage patterns), a teeth whitener
microcontroller (e.g. MC68CH11 with ROM, RAM and FLASH), teeth
whitener microcontroller operating programs, a teeth whitener
active junction temperature environmental control means, a teeth
whitener light source cooling means, a teeth whitener control means
(with operation lockout features), a teeth whitener communications
means (for connecting proximity sensors), a teeth whitener timer
means (with maximums and responsive to logic in the case of a poor
fit restart of a single session), a battery (for portable
operation) useful for the purpose of teeth brightening teeth with
reduced hazards. Wherein said dental light directing means is
commercially available and sold under the name "Twilight Teeth" UV
light catchers used in combination with UV LED for the adaptation
of the commercially available tooth brightener, where said UV LED
includes but is not limited to UV light emitting diodes, wherein UV
light emitting diode includes but is not limited to UV-395-TO92
manufactured by Bivar Corp, Irvine, Calif., USA, to NSHU550A
manufactured by Nichia USA, and to LC503MUV1-30Q a 5 mm t-1 3/4
package from Marktech Optoelectronics, Menands, N.Y., USA.
Temperature Dependent Wavelength Shifting for Phototherapy
Applications
[0124] Another aspect of the present invention provides a means of
varying the nominal wavelength of emitted light by heating and/or
cooling the UV light emitting LEDs. This is useful for obtaining
wavelengths other that the nominal wavelength of the LED which
would be required for particular phototherapy prescriptions, such
as lupus phototherapy where it is desirable to vary the wavelength
of the light during treatment.
[0125] In LEDs the most common typical wavelength shifting observed
is referred to as a red-shift, wherein the typical shift of the
wavelength of emitted light is toward longer wavelengths. In light
emitting diodes that do not have the benefit of the present
invention the temperature of the semiconductor junction gets hotter
with increased electric current and the forward voltage drop in the
active junction increases resulting in the wavelength shift.
[0126] Operating LEDs at lower than normal temperature is useful in
shifting the wavelength of the emitted light to a range that is not
emitted under normal operating conditions, which includes but is
not limited to a controlled shift toward shorter wavelength, herein
referred to as a blue-shift. Shifting the emitted output of the
LEDs is useful to implement phototherapies that require certain
wavelengths that are not normally available from the LEDs.
[0127] Some embodiments of the present invention incorporate
combinations of LED cooling means and LED heating means useful for
controlling the temperature of the LED active junction in an
arbitrary dynamic pattern responsive to the output of a
phototherapy control algorithm.
[0128] Cooling of LEDS may be carried out using a thermal
insulation means in proximity to cold compressed refrigerant piping
means for the useful purpose of keeping said cold compressed
refrigerant piping to said LEDs and in particular the heat
generating mass of the LED including the active junction of the
LED. Any suitable cooling fluid, including water or alcohol based
fluids may be used to cool the LEDs. LED cooling is described in
greater detail below.
Multiplexing Phototherapies
[0129] Still another aspect of the invention provides systems,
devices and methods for phototherapy that use one UV source (i.e.,
at least one UV emitting LED or a nanostructured UV light emitting
device) to irradiate multiple body parts or multiple people. These
systems, devices and methods may find use is a broad variety of
phototherapy applications, including tanning, lupus phototherapy,
psoriasis phototherapy, teeth whitening and hair growth
phototherapies. Some such devices, including those that have
controllable mirrors or mechanically translating UV sources have
already been described. Other such systems are described here.
[0130] In some embodiments, the systems, devices and methods
include a combination of reflective surfaces or optical pipes to
direct light from a horizontal light due to vapor phase changes to
any direction of light. In some embodiments a wall of a device
(i.e., a phototherapy chamber wall) has a light modifying means in
order to redirect the light in a manner that distributes the light
according in a manner consistent with a indoor tanning mode or a
phototherapy mode. One example of a light modifying means is a
lens. Other light modifying means include, but are not limited to,
reflective surfaces, optical lens, and light pipes.
[0131] A further embodiment of the present invention incorporating
said light provisioning means, a plurality of said light wave guide
means, and a light directing means, for the useful purpose of
provisioning light from remote sources relative to the phototherapy
chamber, on the order of 100 feet or less. The useful purposes of
provisioning light remotely includes but is not limited to the
purpose of time sharing the light provisioning source, the purpose
of more effective cooling at a remote location, and for the purpose
of reducing the number of components in a multiple phototherapy
chamber enterprise by time sharing the LED array. Wherein said
light directing means switches the direction of light from one
wave-guide to another depending on a control system which manages
the sharing of the light provisioning means.
[0132] A further embodiment of the present invention incorporates a
plurality of light provisioning means, a plurality of said light
wave guide means, and a plurality light directing means, for the
useful purpose of provisioning light from remote sources relative
to the phototherapy chamber, on the order of 100 feet or less. The
useful purposes of provisioning light remotely includes but is not
limited to the purpose of time sharing the light provisioning
source, the purpose of more effective cooling at a remote location,
and for the purpose of reducing the number of components in a
multiple phototherapy chamber enterprise by time sharing the LED
array. Wherein said light directing means switches the direction of
light from one wave-guide to another depending on a control system
which manages the sharing of the light provisioning means.
[0133] Yet another embodiment of the present invention incorporates
said light wave guide means wherein said light wave-guide means are
comprised of light transmitting means including but not limited to
light collecting means, reflective mirrors, and reflective tubes,
which may be hollow reflective tubes. The reflective tubes may be
fiber optic tubes, comprised of materials including but not limited
to glass, plastic, UV transparent fluid.
Thermal Management
[0134] Another aspect of the present invention provides systems and
methods for achieving high levels of thermal efficiency in devices,
including both phototherapy and general lighting devices, that use
the UV LEDs and nanostructure UV light emitting devices provided
herein. In this aspect of the invention cooling methods are used to
more effectively transfer heat from light emitting diodes to the
ambient environment by introducing liquids, such as a the cooling
fluid, near the active junction of the light emitting diode to
transfer heat from the LEDs to the ambient environment. These
cooling methods may use one or more types of cooling, including
immersion cooling, liquid cooling and evaporative cooling.
[0135] A low active junction temperature (within the manufacturer's
specifications) is useful because it allows the light emitting
diode type LED to be either overdriven with electric current
(described below) while maintaining the rated life of the LED, or
to extend the life of the LED while maintaining electric current
under rated maximums.
[0136] The systems and methods are described in detail in U.S.
Provisional Patent Application No. 60/552,018, (e.g., on pages
25-43) the entire disclosure of which is incorporated herein by
reference. A more abbreviated description is provided here.
[0137] The methods may be used to cool various electronic
components, including encapsulated LEDs and bare LED dies. For
example, the methods are used to cool open framed light emitting
diodes. Said open framed light emitting diodes are not
encapsulated. The use of open framed UV light emitting diodes
reduces the manufacturing tooling costs associated with custom chip
on board technology while still allowing for the direct contact
immersion cooling of said LED die. These open framed UV light
emitting diodes may be obtained by diverting open framed light
emitting diodes out of an industry standard LED manufacturing
process after the wire bonding manufacturing process and before the
encapsulation manufacturing process is applied.
[0138] A further embodiment of the present invention incorporates a
coating on said LEDs to protect said LEDs from the chemical
reaction potential of the cooling fluid and the force of said
cooling fluid flow. The coating is preferably a highly transparent
coating and, in the application of indoor tanning or other
phototherapies, a highly UV transparent coating. The coating may be
comprised of materials including, but not limited to, silicone
compounds, to silicone sealant, and to epoxies.
[0139] In carrying out the cooling methods, the cooling fluid may
be directed near and/or between LEDs or LED chips. The cooling
fluid may be directed using a variety of conduits including, but
not limited to tubing, micro-channels, Venturi tubes, expansion
valves, and porous substrates. The cooling methods may be carried
out using a built-in cooling source means which may be an integral
component of a phototherapy chamber or a general lighting device.
In the former instance, the cooling source may be used to cool the
UV light source in the chamber, as well as the chamber itself.
Typically, the cooling source will include means to transport
(including directing and propelling) cooling fluid to the proximity
of the active junction of at least one light emitting diode and
insulating means to keep the cooling fluid cold during transport.
In addition, the cooling source may include a cooling control
system responsive to inputs, including but not limited to estimated
active junction temperature, and to measured active junction
temperatures.
[0140] Water is one non-limiting example of a cooling fluid that
may be used in accordance with the present invention. Other
suitable cooling liquids include mixtures of alcohol (e.g.,
isopropyl alcohol) and water, air, perfluorocarbons and silicone
oils.
[0141] If the UV source to be cooled is part of a phototherapy
system and the cooling fluid flows in front of the light source,
the cooling fluid is desirably optimized for the requirements of
the particular phototherapy being conducted. For example, the light
transmission properties of the cooling fluid may be chosen to be
high in transmission of the wavelengths useful in said phototherapy
and low in transmission of light that is prohibited or undesirably
in said phototherapy. Thus, for indoor tanning the wavelength of
transmission would desirably be limited to 400 nm to 300 nm, and
for lupus therapy the wavelength of transmission would desirably be
limited to 400 nm to 340 nm.
[0142] Perfluorocarbon cooling fluids are well suited for use as
coolants in UV light emitting devices because they are generally
good at transmitting UV light. In some embodiments the
perfluorocarbon cooling fluid has a relatively low atomic mass and
a boiling temperature between 30 and 40 degrees Celsius at 1
atmosphere pressure. An example of such a chemical has boiling
point of 29 degrees Celsius, has a molecular weight of 288, is
labeled PP50, and is manufactured by F2 Chemicals Ltd (Lee Lane,
Lea Town, Nr Preston, PR4 ORZ, UK). In other embodiments, the
perfluorocarbon cooling fluid has a relatively high molecular
weight and boils above 130 degrees Celsius at 1 atmosphere (ATM).
An example of such a chemical has a elemental mass of 462 is
labeled PP6 and is manufactured by F2 Chemicals Limited (Lee Lane,
Lea Town, Preston. PR4 ORZ, United Kingdom).
[0143] In some embodiments, the cooling fluid undergoes pool
boiling or nucleate boiling. This may be advantageous because the
hottest points of the LED are the places where the boiling occurs
and are also where the most cooling is needed. In other
embodiments, the cooling fluid is a heavier cooling fluid that
boils at a temperature and pressure well above those found in
proximity to an LED, e.g., PP6, manufactured by F2 Chemicals
Ltd.
[0144] Magnetic and paramagnetic cooling fluids may also be used.
For example, the invention may incorporate a magnetic fluid means,
including but not limited to a magnetic fluid wherein, said
magnetic fluid has elements including, but not limited to, iron
and/or nickel. Additional magnetic fluids that comprise a magnetic
material may be selected from the group consisting of Cr, Mn, Fe,
Co, Ni, V, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb,
Ac, Th, Pa, U, Ne, Pu, Am, Cm, Bk, Cs, Es, Fm, Md, No, Lr, Tb--Fe,
Gd--Fe, Nd--Fe, Gd--Co, Er--Ni, U--Co, Fe.sub.4N, Fe.sub.5N, and
Fe.sub.3O.sub.4. Or the invention may incorporate a paramagnetic
fluid means including, but not limited to, a paramagnetic fluid
wherein, a paramagnetic material comprises a paramagnetic material
selected from the group consisting of silica, alumina, yttria,
zirconia, hafnia, titania, niobia, Ag, Al, Cu, Si, Au, Pt, Pd, Rh,
Ru, Mo, Nb, Ta, W, Ti, V, Zr, Hf, Y, Re, Ir, Ga, In, Sn, Pb, Zn,
Cd, Hg, Ag--Al, Cu--Al, Pd--Ag, Al.sub.2O.sub.3, SiO.sub.2, BN,
NbN, TaN, TiN, Fe.sub.2O.sub.3, CoO, Ni.sub.3Al, and FeAl.
[0145] Magnetic elements may also be combined with non-magnetic
fluids to impart magnetic characteristics. For example, a
perfluorocarbon fluid with an integral magnetic element such as
iron, nickel or a ferrofluid, ferroperfluorocarbon fluid, including
the Flutec Ltd, fluid, Ferrofluid, may be used as a cooling
fluid.
[0146] In one cooling device, the magnetic or paramagnetic fluid
means passes through a micro coil which creates an electric field
potential in the coil as the magnetic or paramagnetic fluid comes
to magnetic saturation. Magnetic saturation in the magnetic or
paramagnetic fluid decreases after passing through the
non-energized micro coil and entering the open ventricle of a micro
stirling engine wherein there is cooling due to the magnetic
interactions of the magnetic or paramagnetic fluid that begins to
randomize from the heat contained in a cold source within the
magnetic forces between the magnetic or paramagnetic fluid. Each
time the magnetic or paramagnetic fluid passes between
thermodynamic chambers the magnetic energy will either be absorbed
or allowed to pass through depending on the controlled state of a
current control means.
[0147] A further embodiment of the present invention regenerates
electricity by operating a current control means in a second mode
where the heat of an electrically powered first LED produces
mechanical pressure in a first magnetic fluid chamber forcing said
magnetic fluid through a micro coil aperture into a second magnetic
fluid chamber which creates an electric current potential useful
for generating electric energy. As the ferromagnetic fluid passes
through the micro coil the ferromagnetic fluid is cooled. At the
end of the cycle the first LED is no longer powered and a second
LED in contact with second magnetic fluid chamber transitions from
no power to power which heats the magnetic fluid in the second
chamber and forces the magnetic fluid back into said first magnetic
fluid chamber in combination with a current switch receiving
current from the micro coil which rectifies the current through the
coil in the opposite polarity relative to the first cycle which is
useful for power generation. In addition to regenerating electric
current from heat the fluid flow cools the LED surface providing
longer life at overdriving conditions (discussed below).
[0148] A further embodiment of the present invention incorporates a
means to convert power in the form of heat transfer into useful
work power such as electricity and or mechanical movement, such as
fluid flow. This conversion process may be in the form of a Carnot
cycle, Stirling cycle, Brayton cycle, Ericsson cycle or a
thermodynamic cycles of a Stirling engine, including a
micro-Stirling engine, wherein the resultant work power is in the
form of electric current at a active junction electric voltage
potential and used to power the LEDs or to operate other device
components, such as fans and pumps.
[0149] Other components that may be included in the systems
include, but are not limited to, a pneumatic force imparting means
to create forced convection in the cooling fluid and to increase
heat transfer fluid force vectors beyond the force vectors provided
by the natural convection; and an ultrasonic frequency means to
effect the reduction of additional barriers of heat flow near the
surface of said LEDs.
Overdriving LEDs
[0150] The cooling methods of the present invention allow the LEDs
to have increased heat transfer which allows operation at a lower
active junction temperature for a given current, as compared to the
prior art which relied on heat transfer through air. The maximum
allowable current through each LED will be increased as a result of
the increased heat transfer and a lower active junction
temperature, thereby allowing each LED to produce more photons. The
increase in the quantity of emitted photons per LED die allows for
a reduction in the total number of LEDs used for a given
application (e.g., to create a phototherapy chamber for a desired
session time). The reduction in the total number of LEDs lowers the
cost of said application. The mode of operation wherein more
electric current is applied to the LED that the rated maximum is
referred to as overdriving LEDs.
[0151] It should be noted that overdriving the LEDs for short
periods of time and overdriving the LEDs with short duty cycles
over long periods of time will not require a cooling system under
normal ambient conditions to achieve a rated life of the LED array.
Unfortunately, overdriving the LEDs for short periods of time and
overdriving the LEDs with short duty cycles over long periods of
time are not useful conditions of operating the LED array for the
purposes of many phototherapy procedure including but not limited
to indoor tanning, and lupus therapy. An example of a phototherapy
requiring additional LEDs is the condition where an area of skin is
to be treated and the wavelength of the emitted light is required
to be within a range that is only possible to achieve with LEDs
that are operated with short duty cycles.
Power Sources
[0152] A final aspect of the invention provides various circuits
that may be used to power the LEDs used in the present systems and
devices. These circuits are depicted in FIGS. 12 through 15. FIG.
12 shows a basic circuit for use in powering LEDs. FIGS. 13a, 13b,
and 13c show variations in the circuit. FIG. 14 shows a direct line
voltage power supply that has a useful near unity power factor LED
transfer function which is useful to remove the need for a
switching power supply utilizing resistor ladder network to creates
bias for transistors. FIG. 15 shows a direct line voltage power
supply that has a useful near unity power factor LED transfer
function which is useful to remove the need for a switching power
supply utilizing resistor ladder network to creates bias for
transistors. Field effect transistors may also be used in
equivalent circuits. Also, microcontrollers with analog to digital
and digital to analog converters may be used in addition to or in
place of the resistor ladder networks shown in the figures.
[0153] U.S. Provisional Patent Application No. 60/473,237, filed
May 24, 2003 and U.S. patent application Ser. No. 10/714,824 are
hereby incorporated by reference in their entirety.
[0154] The foregoing description of the invention has been
presented for purposes of illustration and description. It is not
intended to be exhaustive or to limit the invention to the precise
form disclosed, and modifications and variations are possible in
light of the above teachings or may be acquired from practice of
the invention. The drawings and description were chosen in order to
explain the principles of the invention and its practical
application. It is intended that the scope of the invention be
defined by the claims appended hereto, and their equivalents.
* * * * *