U.S. patent application number 14/217356 was filed with the patent office on 2014-09-25 for multispectral therapeutic light source.
The applicant listed for this patent is Gary W. Jones. Invention is credited to Gary W. Jones.
Application Number | 20140288351 14/217356 |
Document ID | / |
Family ID | 51538166 |
Filed Date | 2014-09-25 |
United States Patent
Application |
20140288351 |
Kind Code |
A1 |
Jones; Gary W. |
September 25, 2014 |
MULTISPECTRAL THERAPEUTIC LIGHT SOURCE
Abstract
A light source apparatus including light spectrum-converting
materials that emit light primarily over large portions of the 360
nm-480 nm and the 590-860 nm spectral range is provided. This
apparatus provides a cooled, high-luminance, high-efficiency light
source that can provide a broader spectrum of light within these
spectral ranges than has been cost-practical by using many
different dominant peak emission LEDs. Up to 15% of the output
radiant power may be in the spectral range 350-480 nm in one
embodiment of this device, unless a specific separate source and
lamp operating mode is provided for the violet and UV. Control
methods for light exposure dose based on monitoring and controlling
reflected or backscattered light from the illuminated surface and
new heat management methods are also provided. This flexible or
rigid light source may be designed into a wide range of sizes or
shapes that can be adjusted to fit over or around portions of the
bodies of humans or animals being treated, or mounted in such a way
as to provide the special spectrum light to other materials or
biological processes. This new light source can be designed to
provide a cost-effective therapeutic light source for photodynamic
therapy, intense pulsed light, for low light level therapy,
diagnostics, medical and other biological applications as well as
certain non-organic applications.
Inventors: |
Jones; Gary W.; (Newcastle,
WA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Jones; Gary W. |
Newcastle |
WA |
US |
|
|
Family ID: |
51538166 |
Appl. No.: |
14/217356 |
Filed: |
March 17, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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61802234 |
Mar 15, 2013 |
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Current U.S.
Class: |
600/9 ; 601/18;
607/3; 607/90 |
Current CPC
Class: |
A61N 2005/0652 20130101;
A61N 1/0452 20130101; A61N 1/0456 20130101; A61N 2005/005 20130101;
A61N 5/0624 20130101; A61N 5/0616 20130101; A61N 2/002 20130101;
A61N 5/06 20130101; A61N 2005/0632 20130101; A61N 2005/0626
20130101 |
Class at
Publication: |
600/9 ; 607/90;
601/18; 607/3 |
International
Class: |
A61N 5/06 20060101
A61N005/06; A61N 2/00 20060101 A61N002/00 |
Claims
1. A light emitting device for generating a predominantly
non-coherent output light, comprising one or more spectrum
converters, one or more LEDs, and one or more power supplies
arranged for energizing the one or more LEDs, wherein the device is
configured to produce the output light with an output photon flux
that is predominantly in the orange-to-near-infrared (ONIR) 595
nm-960 nm spectral range, and with light energy at all wavelengths
within such ONIR spectral range, wherein the light emitting device
exhibits all the following characteristics: (a) one or more of the
LEDs are overlaid with one or more spectrum-converting fluorescent
and/or phosphorescent containing materials or photonic
spectrum-shifting structures, as said spectrum converters; (b)
converted LED light sources with spectrum converters in the light
emitting device are configured to contribute over 25% of the total
output radiant light power of the output light; (c) internal
quantum yield of spectrum converters averages over 60% when
independent of the light emitting device and under optimal
conditions; (d) one(s) of the one or more LEDs to be spectrum
converted provide dominant spectral emission peaks between 350 nm
and 480 nm and/or between 590 and 780 nm; (e) 350 nm and 480 nm
dominant peak LEDs with spectrum converters use a phosphor or QD as
the spectrum converter for absorption of over 70% of the normal
angle LED radiant power light; (f) 600 nm-780 nm dominant emission
peak LEDs with spectrum converters use a fluorescent dye or QD
spectrum converter for absorption of over 30% of the normal angle
LED radiant power light; (g) over 70% of the total output light
from the device is in the 595-960 nm spectral range; (h) at least
1% of the highest radiant power peak in the 600 nm-750 nm part of
the emitted light spectrum of the output light is provided at all
wavelengths between 600 nm and 820 nm; (i) LED(s) of the one or
more LEDs, whose light is not significantly absorbed by the
spectrum converters comprise LEDs with dominant peak wavelengths
within the 350 nm-480 nm spectral range and/or within the 650 nm to
960 nm spectral range; (j) the device comprises a lighted window at
which the light output is emitted, and the device provides at least
5 mW/cm.sup.2 average radiant power output in a primary lighted
portion of the lighted window and the primary lighted portion of
the lighted window comprises a lighted area of at least 4 cm.sup.2;
(k) at least 60% of the area of the primary lighted portion of the
lighted window contains over 30% reflective surfaces at the highest
spectral emission peak of the output light, not including area used
by LEDs or spectrum converters, to reflect light back into the
output light; (l) LED light is provided by at least one of the one
or more LEDs behind the lighted window, in the perimeter of the
lighted window, or brought to the lighted window using fiber
optics; (m) a thermal controller is arranged to interrupt or reduce
power from the one or more power supplies when the temperature at
the LED heat sink or at the LEDs inside the device exceeds a
predetermined value; and (n) wherein when the LED light is not
brought to the window by fiber optics, the thermal controller is
effective to prevent the light-output side surface temperature of
the device from exceeding 70.degree. C. after 60 minutes of device
operation in a 35.degree. C. ambient environment.
2. The device of claim 1, wherein the spectrum converters comprise
a phosphor, fluorescent or phosphorescent dye, and/or quantum dots
with substantial light absorption in the under 480 nm spectral
range, and/or a fluorescent dye or photonic crystal structure with
the majority of its absorption spectrum in the under 650 nm
spectral range, and where over 70% of light emission from the
spectral converters is within the 595 nm to 950 nm spectral
range.
3. The device of claim 1, comprising rows or columns of said LEDs
on one or more flexible circuit connection backing arrangements,
and/or comprising a multiplicity of rigid LED modules that can be
placed so as to provide therapy light from two or more angles.
4. The device of claim 1, comprising control circuitry configured
to operate the device at a constant luminance, or modulated at one
or more frequencies and at one or more duty cycles.
5. The device of claim 1, comprising a backside heat sink structure
comprising heat conducting belt loops configured to dissipate at
least 25% of the total heat load from the one or more LEDs and/or
comprising sections of heat conducting belts in contact with said
belt loops.
6. The device of claim 1, comprising a backside heat sink structure
that permits air flow around and/or through a backside radiator
that includes four or more heat conducting materials formed as
fins, waves, tubes, or folds bonded to a heat conducting base
structure.
7. The device of claim 1, comprising a backside heat sink
structure.
8. The device of claim 1, wherein the lighted window comprises one
or more windows on a top side of the device where the light output
is emitted, wherein the active-light window area in front of the
LEDs has one or more translucent windows providing low thermal
conduction to the skin or other tissue, comprising a 2D or 3D
matrix of liquid, gel, or air filled gas pockets or channels, and
comprising low-thermal conducting top surface materials; air or gas
is flowed through the pockets or channels to improve heat removal;
bumps and/or raised patterns and/or recessed patterns are disposed
between two or more transparent layers between the one or more LEDs
and the windows; bumps or fiber like extensions of surface
material, or a matrix of LED-coupled fibers protrudes through a
window; a top outer surface of a window comprises a grid of wells
to provide air pockets to reduce heat transfer through the windows
and/or to hold materials for application to the skin; and/or the
lighted window is formed of a low index of refraction silicone or
multiple layers of low index of refraction coatings or films are
provided at a surface of the lighted window.
9. The device of claim 1, comprising a monitoring and control
assembly including one or more light sensors placed in, on, and/or
near the lighted window, facing, toward a target surface when the
device is in use so that the sensor(s) detect reflected light from
the target, with the sensor(s) arranged to provide input to a
controller circuit to adjust light intensity based on reflectivity,
and/or to adjust the time of treatment.
10. The device of claim 1, comprising a monitoring and control
assembly including one or more temperature sensor(s) arranged to
directly or indirectly monitor a target surface temperature and
provide corresponding input to a controller configured to modify
light intensity and/or treatment time of the device.
11. The device of claim 1, wherein the LEDs are positioned toward
bundles of fiber optic loops or coils to concentrate light in a
forward direction and comprising phosphors, quantum dots,
fluorescent or phosphorescent dye, dye-doped fibers, and/or
photonic crystal fibers to provide spectrum conversion.
12. The device of claim 1, comprising one or more piezoelectric,
capacitive, inductive, or magnetostrictive transducers or motors to
generate sonic and/or ultrasonic energy and/or vibration from,
and/or in the vicinity of the output light as continuous and/or
pulsed energy.
13. The device of claim 1, comprising electrodes configured to
generate pulsed AC current to stimulate tissue surface and tissue
locally under and near the output light.
14. The device of claim 1, comprising two or more >5 gauss
magnets.
15. The device of claim 1, comprising one or more controllers that
are programmably arranged to turn the device off at an end of a
programmed time.
16. The device of claim 1, comprising a cooling system configured
to pump or suction air through an interior region of the device
and/or for air over a heat sink in the device, and/or a water
recirculation heat exchanger.
17. The device of claim 1, comprising a diaphragm or bellows air
pumped cooling system.
18. An LED array light source comprising channels arranged for
peristaltic air pumping when the light source is bent and/or moved
to increase convection flow in and out of the channels to effect
heat removal from the LED array.
19. A method of light therapy treatment of a subject in need
thereof, said method comprising generating a modified light
spectrum output using a device according to claim 1, and exposing a
body region of the subject to the light output thereof.
20. The method of claim 19, wherein the light therapy treatment is
carried out to treat: joints and muscles for reducing pain and
inflammation; wounds for improving the rate of wound healing; acne,
rosacea, skin tone, and other dermatological conditions, to improve
healing, and reduce the population of bacteria or fungus that are
directly or indirectly photosensitive to the light spectrum of the
light therapy treatment; muscles for enhancing regeneration of
tissue after exercise or other stress; bone areas to repair damage
and improve bone density; head, neck, spine, or other body areas,
for pain and inflammation, for mood treatments, for reducing damage
from brain injuries, or for increasing generation of nerve stem
cell; veterinary subjects; photochemicals from food, herbs, and/or
photochemical drugs for phototherapies; plants to enhance plant or
algae growth or to control other plant functions selected from the
group consisting of ripening, seed formation, and bud formation; or
water and other fluids to activate photosensitizers for
purification and/or antimicrobial and/or other pathogen treatments.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The benefit of U.S. Provisional Patent Application No.
61/802,234 filed Mar. 15, 2014 in the names of Gary W. Jones for
"MULTISPECTRAL LIGHT SOURCE" is hereby claimed under the provisions
of 35 USC 119. The disclosure of U.S. Provisional Patent
Application No. 61/801,602 is hereby incorporated herein by
reference in its entirety, for all purposes.
FIELD
[0002] The present disclosure relates to a multispectral light
source having utility for light therapy and other applications.
DESCRIPTION OF THE RELATED ART
[0003] Light therapy devices and methodologies that have been
publicly reported or claimed include (1) Low level light therapy
(LLLT) for the treatment of inflammation and/or for tissue surface,
other tissue healing, skin and tissue rejuvenation, muscle growth
enhancement, muscle repair and pain reduction, accelerated tendon
healing, joint or cartilage treatments, plantar fasciitis, pain
management, traumatic brain injury (TBI) damage risk reduction,
neurologic rejuvenation, enhancing stem cell generation, enhancing
mood, and/or enhanced rate healing of wounds, blood and body fluid
treatments (with or without photosensitizers), spider vein and/or
varicose vein and/or scar and/or stretch mark reduction treatments
with or without photosensitizers, reducing arterial plaques or
other undesired biological materials using photosensitizers,
treating biofilms on natural and/or man-made surfaces in or on the
body, carpal tunnel, fibromyalgia, tendonitis, bursitis,
tendonitis, migraines, carpel tunnel, osteoarthritis, dental root
and implant healing or bone regrowth, for enhancing the rate for
other bone healing, accelerating T-cell life cycles and activity,
accelerating macrophage action, veterinary applications, and/or
providing many other health related medical benefits, (2)
Activation of photosensitizers used in Photodynamic therapy (PDT)
for cancer or antimicrobial treatments using natural or synthetic
photosensitizers, including photosensitizers produced by bacteria
in or on the body, (3) Imaging and diagnostics using the emitted
light spectral range, (4) Intense Pulsed Light (IPL) therapies,
sidereal or other mood therapies, (5) activation of adhesives or
scaffolding agents as a part of reconstructive or cosmetic surgery,
(6) photoactivation of release agents to separate structures of
compounds for surfaces, (7) powering of photocell driven devices in
the body, and/or (8) other uses such as light-sensitive chemical
activation, and/or use of this light therapy in combination with
ultrasonic, vibration, thermal heating or cooling, and other
combinational therapies.
[0004] Non-therapy biological uses of devices using parts of these
spectral ranges are (1) Enhancing plant growth, blooming, and/or
ripening, (2) Enhancing algae growth, photo-bacteria growth, and
other photosynthesis or other photosensitive biological processes,
(3) microbial stimulation, (4) increasing antimicrobial action on
or in materials using photosensitizers (e.g., water or foods),
and/or (5) visual image enhancement for enhanced detection of
materials with unique light absorption and emission
characteristics.
[0005] The accessibility and effectiveness of these therapies can
be enhanced by a collective matrix of improved energy efficiency,
higher light intensity, generating light more efficiently,
transmitting light into tissue more efficiently, reduced
unintentional heating of the illuminated tissues, covering larger
portions of the therapeutic spectral ranges than practical with
conventional LEDs and lasers, enabling easy-to-produce flexible
designs, ease of integration with many other therapies, and/or
lowering the complexity and potential cost of multi-wavelength
light therapy systems.
[0006] For deep-tissue and deep nerve, brain, joint, or bone
therapy applications, this multifaceted need for lower cost, high
intensity, efficient to transmitting light into tissue, comfortable
light sources is very important. Above 650 nm light is considered
most useful for penetrating deeper into tissue, although the energy
per photon available to induce photochemical processes decreases as
the wavelength increases, rather than just radiant heating. Since
multiple light spectrum and intensity influenced biological
processes exist, and light penetration varies by tissue type and
wavelength, a broad spectrum light source covering most of the
Orange to Near-Infrared (ONIR) spectral range light range within
595-860 nm, is important.
[0007] Conventional light therapy methods covering wavelengths
within the ONIR spectral ranges compromise important parameters
excessively to the point where few are effective using practical
exposure times, or are very expensive. Also, LED and laser light
sources are typically restricted to a few wavelength peaks with
less than a +/-30 nm spread to under 10% of the peak light emission
for each type of LED unless many LEDs or lasers are combined.
[0008] Light sources used for activating photosensitizers typically
use narrow spectrum light from lasers or non-laser LEDs, although
other light sources such as filtered halogen light sources or even
sunlight and room ambient are sometimes used for dermatology PDT.
Multiple photosensitizers and reporters may be used together, and
may require multiple excitation wavelength ranges or broad spectrum
activation light. LLLT processes and photosensitizer activation
processes may be used in combination processes.
[0009] Light spectrum and intensity output with some similarity to
those provided by the invention described herein can be obtained by
other types of light sources: (1) using mixtures of multiple
different color LEDs and/or laser diodes, but this can be expensive
and more complicated to manufacture at low cost for large area
light sources, and (2) by filtering out light at some wavelengths
of light from broad-spectrum light sources such as gas discharge
lamps, fluorescent, or halogen lamps but these techniques are also
expensive, generate excessive heat, and waste energy when applied
to large area high intensity lighting applications.
[0010] Fluorescent dyes, quantum dots, and phosphors have been used
for printed fluorescent signs and paints; dye or phosphor
conversion of blue LEDs into white LEDs have been used for visible
lighting, display backlights, in instrument panels, and converting
sunlight more into longer wavelength spectral ranges to improve
solar cell efficiency, and many other applications.
[0011] Light sources using spectrum conversion with
photoluminescent dyes, phosphors, pigments, quantum dots or other
nanoparticles, photonic crystals and other materials or
nanostructures are known and many spectrum conversion methods are
widely used in many commercial lighting products such as white
LEDs, displays, fluorescent light bulbs, and many other
applications. The use of red phosphors is known with 660 nm and 670
nm phosphors being commercially available. The use of multiple
tandem phosphors is known (US 2012/0043552 AI) to down convert to
longer wavelengths, although light losses occur at each conversion.
Dyes with light emission characteristics in the red to near IR
range are also known.
[0012] Currently available light spectrum spectral conversion or
shifting technologies provide relatively low overall light spectrum
conversion efficiency and/or costly conversion of 360 nm-650 nm
spectral range input light into the ONIR spectral range above 650
nm. Many current light therapy sources also only provide light in
small portions of the ONIR spectral range, generate excessive
amounts of heat, require high input power and poor energy
efficiency, provide low efficiency light transmission into the
tissue, are not sufficiently photostable, and costly in systems
that can provide deep penetrating near-IR light at high intensities
(even over 50 mW/cm2).
[0013] Up to 80-85% internal quantum yield (QY) red phosphors are
available at high cost per gram, while lower-cost red phosphors may
be under 60% internal quantum yield and less stable. Small amounts
of lower cost red phosphors are now commonly combined with YAG:Ce
cool-white phosphors (mixed or in subsequent parts of the light
source) to make warm-white LEDs. Light scattering by phosphor
particles and phosphor matrix adsorption losses can cut the output
light efficiency by another 20 to 30%, depending on the amount of
phosphor used and overall design used due to internal scattering by
phosphor particles and other losses. Higher concentrations of
phosphor particles or a larger volume phosphor matrix is needed for
over 80% light conversion to the phosphor's spectral emission
range, but this can reduce the external QY efficiency by another
30%. Near IR phosphors have been shown, but few good choices are
available commercially at this time.
[0014] Quantum dots (QDs) are available commercially in many
different spectral ranges for lighting, displays, and for
biological labeling and staining. QDs are just beginning to become
available commercially at pricing potentially suitable for light
sources. QDs can provide good QY in the 70-90% range, exhibit lower
scattering losses than phosphors, and can function in a wider range
of polymer medium than most high performance photoluminescent
dyes.
[0015] Organic dyes in polymer matrices that exhibit high quantum
yield in the over 90% range for ONIR light have generally not been
seriously considered sufficiently stable for high luminance light
sources, have only recently become commercially available, and/or
have poor extinction coefficients in the desired light absorption
spectral ranges so they require large quantities of dye when
>90% of the incoming light is to be converted into the ONIR
spectral range. Conversion of violet or blue light to ONIR light
using most organic dyes requires a large stokes shift or multiple
stacked dyes, resulting in poor photostability, added complexity,
high cost, and poor energy efficiency. Fluorescent dyes are
typically not used in LEDs as it has been non-obvious how to
accomplish this using available dyes in reasonable medium,
photostability issues, and the stokes shift is usually small so
most red emitters tend to absorb poorly in the violet-blue.
[0016] Non-fluorescent dyes are sometimes used as filters to absorb
portions of the light spectrum to provide more pure visual color,
but absorption filtering wastes a significant amount of light and
is usually undesirable for our applications unless it is to block
UV or long wavelength IR.
[0017] Biological applications for fluorescent dyes, quantum dots,
and phosphor-like nanoparticles have included tagging and tracking
of biological materials, and use as photosensitizers or in
photodiagnostic systems. Photoacoustic applications have also been
reported. Most ONIR range photoluminescent materials are very
expensive per gram of dye, not very high quantum yield, and/or
provide poor stability in use. Fortunately, many medical dye
applications do not require as high photostability as solar cell
conversion or other lighting applications, high quantum yield and
high extinction in the red to near-infrared spectral range.
Unfortunately, minimal heat producing, high intensity light source
applications for light therapy, as an example, do require all the
parameters to be simultaneously met.
[0018] Even though the name "low level light therapy" or LLLT
implies the use of low-intensity light, high-intensity light
(>10 mW/cm2 or even >100 mW/cm2) is frequently desired to
reduce the treatment time, or to obtain adequate intensities of Red
and near-infrared (NIR) light into deep-tissue where the light
intensity may be several orders of magnitude lower than at the
tissue's surface. Even deep penetrating NIR light intensity may be
1,000-10,000.times. lower at 4-8 centimeters below the skin surface
than at the light source. Considerable light is lost in many
systems just due to unrecovered skin reflection losses. Almost no
practical products available to consumers or clinics provide the
total absorbed light dose necessary for treatment over 4 cm deep in
tissue and/or through living bone in an under 30 minute exposure
time per location, and those that do provide high intensity light
are typically expensive and require high power lamps and/or
extensive heat control capabilities.
[0019] Many light therapy systems have been shown.
[0020] Non-photosensitizer PDT and LLLT may use narrow spectrum
light, multiple peak spectrum light, or broad spectrum light to
penetrate different depths through different types of tissue and/or
to activate or drive different chemical and biochemical processes
or different photosensitizers. While certain narrow spectrum
wavelengths may be optimal for certain processes, a range of
wavelengths can be more desirable for LLLT, some single
photosensitizer PDT making use of different penetration depth of
different wavelengths of light, multiple photosensitizer PDT, PDT
with separate diagnostics, multiple fluorescent reporter
applications, and some combined PDT and LLLT treatments.
[0021] Intense pulsed light (IPL) is used for many treatments with
lasers, gas discharge, or halogen lamps. Non-laser LEDs can also
deliver high intensity pulsed light, especially if focused or
otherwise condensed (e.g., using tapered fiber optics). These
treatments are frequently used for hair reduction and for treating
a variety of skin conditions such as acne, wrinkles, dark skin
discolorations, moles, or rosacea.
[0022] Small area LED and laser light sources (direct illumination
or through fiber optics) can be used for applications where the
light is directed at a specific tissue-surface target, such as a
basal cell carcinoma. However, for deep tissue light treatments
without the use of skin-penetrating probes, the light scattering
effects for small area sources reduce the effective light intensity
at large depths through tissue significantly. Light sources with
large illumination areas relative to targeted tissue deep under the
skin reduce the effective transverse losses due to lateral light
scattering by tissue, cartilage, or bone behind the center zone of
the light source and therefore can provide higher light intensities
much deeper in tissue and bone than is practical with small area
light sources. Conformal light sources can further improve light
coupling efficiency.
[0023] Of the light that is actually incident on the tissue
surface, up to 50% or more of the incident light is reflected off
of and/or backscattered out of the tissue and is lost for
therapeutic purposes in most commercial system designs. (This
includes laser and non-laser LEDs, other lasers, IPL, OLED, and
other light sources).
[0024] Therapeutic light sources with high reflectance to return
reflected or backscattered light to the tissue can provide superior
therapeutic and diagnostic depth through tissue effectiveness
range.
[0025] Direct skin surface exposure during LLLT frequently can
require long exposures per location even if very high light
intensities are supplied, depending on the incident light
intensity, spectral range of the light, light source and tissue
characteristics, depth of light penetration desired, and the light
dose at the targeted tissue required. This is due to high
scattering and absorption losses even for the best penetrating
near-IR light, even with large area light sources that effectively
reduce some of the scattering losses. This can be very difficult to
practically accomplish using typical under 10 Watt lamp power
consumer handheld or small mounted systems unless strapped to the
body for long periods of time. Without the light source shaped to
the body, reflection and backscatter light loses cannot be
minimized. Therefore, easily adjusted, comfortable, and/or body
shaped body-mounted light source systems are usually more practical
than handheld units or non-conformal light panels.
[0026] In addition to the efficient generation of the selected
therapeutic and/or diagnostic light spectra by the LEDs or other
light generating devices, if the light generated is incident on the
surface tissue over a large area with the illuminated area being
large relative to the targeted tissue (especially if light can be
directed in from multiple sides of the target like a strap all, or
part way around a body part), higher effectiveness can be provided.
Furthermore, much of the reflected or backscattered light from the
tissue surface should be reflected back at the tissue surface.
Occasional movement of the light source can be used to further
enhance the amount of light delivered deeply over a larger area.
This is all known, although seldom well-practiced.
[0027] At the desired high light intensities and treatment duration
times desired for deep-though-tissue or into-bone treatments,
heating of the tissue surface can becomes a major issue for
conformal light sources. Heating of tissue surfaces in conformal
systems held against the tissue surface and cost of high efficiency
light emitting devices at the desired wavelengths has forced
compromises that result in many LLLT products on the market to be
largely ineffective and caused most PDT products to be higher cost
than desirable. Compromises in current products have included: (1)
too low effective light intensity, (2) non-optimal light spectra or
incomplete complement of wavelengths, (3) inability to achieve
deep-in-tissue light doses in practical time periods, (4) poor
therapeutic light transmission deep into tissue, and (5)
overheating of tissue surface discomfort.
[0028] Conformal light sources in near-direct contact with the
target tissue and that reflect reflected light back to the tissue
to be illuminated can best efficiently direct light into tissue,
although available systems do this poorly.
[0029] To optimize the total light absorbed by tissue to tissue
surface heating in an efficient manner, 3 integrated innovations
are necessary for many non-photosensitized based light therapies,
and some diagnostics or photosensitizer based applications.
[0030] Efficient and economical generation of light covering a
large percentage of the spectral range of wavelengths potentially
useful for activation most LLLT biological processes (595-860 nm),
and other specific wavelength ranges such as 390-440 nm
(antibacterial, but above the UVA spectral range).
[0031] An improved method for reflection of light back into the
tissue surface while still reducing heat transfer to tissue in a
conformal-to-tissue-surface light source.
[0032] Simultaneous control of radiant heat, conduction of heat,
and convection heating of the tissue surface when high intensity
large area light sources are used, coupled with cooling methods on
the skin.
[0033] A design that can utilize these multiple methods together
can enable higher intensity light sources to be used or longer
treatment times per location with less discomfort from skin heating
during PDT or LLLT.
[0034] System controls: Timers, over-temperature limiting devices
such as thermocouples with control circuits, mechanical or
electronics temperature limit switches, IR thermal measurement of
skin or device surfaces, and/or the use of controller electronics
to increase cooling or reduce energy to the system are all known
methods for keeping the devices from overheating skin, the light
source(s), or other surfaces. These controls may not always be
necessary for light sources with adequate cooling capability,
reasonably high energy efficiency, and sufficiently low power if
the devices are used properly in open air below 30 deg. C.
[0035] Controllers with data logging and/or RF call of attendant
upon overheat, timer completion, improper operating conditions,
and/or patient activated attendant call-notification capability are
all anticipated.
[0036] People with different skin or tissue absorption, different
skin coatings, different hair type or density, different types of
tissue and biological materials, or different non-biological
materials may experience different amounts of heating, light
absorbance, presence of photosensitizers or reporters, and/or
reflectance. This may occur especially when using a broader
spectral range light source for therapy, diagnostics, or
non-biological chemical activation.
[0037] An IR heat sensor and one or more ONIR light sensors may be
used to determine the amount of light being absorbed by the tissue
and the surface heating, allowing for partial or total
near-optimization of the total light dose and light intensity to
correct for different skin types and tissue types being
treated.
[0038] Thus, an over 10 mW/cm2 broad spectral emission ONIR light
therapy system that emits light conformably over a large area
economically and provides adequate controls for all or most of the
parameters discussed in this section, may provide significant
benefits for a wide variety of biological and medical applications.
The optional addition of up to 50% violet light to ONIR light can
provide antibacterial benefits for skin that can be further
enhanced using photosensitizers.
SUMMARY
[0039] The present disclosure relates to a multispectral light
source having utility for light therapy and other applications.
[0040] More specifically, the disclosure relates to a light
emitting device combined with a spectrum converter and power supply
to provide a primarily non-coherent output light source that
efficiently generates and provides a customizable spectral range
light. Optional features, such as heat sinks, can be applied to
specific embodiments. The output photon flux provided by this light
source is mostly within the orange-to-near-infrared (ONIR) 595
nm-860 nm spectral range, and with light energy at all wavelengths
within this ONIR spectral range. 350 nm-to-465 nm and 595 nm-to-960
nm light may also be present in some light therapy system
embodiments.
[0041] This new light source apparatus uses multiple new light
spectrum converting materials and device structures that can absorb
light in one spectral range from light emitting devices such as
LEDs or laser diodes, and then reemit most of the absorbed photons
in all or part of the ONIR spectral range.
[0042] This light source device can provide a much higher
quantum-efficiency and cost-effective way to provide broad-spectrum
ONIR light output than current commercially available technologies
with reduced surface heating for use in several applications,
including photodynamic therapy (PDT), low level light therapy
(LLLT), light influenced biological processes, diagnostics,
lighting for photo-luminescent based imaging, and/or other medical
and non-medical applications.
[0043] An objective of the present invention is to efficiently
provide output photon flux over all or almost all of the ONIR
spectral range in order to provide reasonably efficient
transmission of the ONIR light into the surfaces being illuminated.
Objectives for this device include accomplishing the generation of
broad spectrum ONIR light at lower system cost, higher energy
efficiency, ability to exceed 10 mW/cm.sup.2 light intensity to the
surface to be radiated, to be scalable for large areas of light
exposure exceeding 100 cm.sup.2, and/or with the potential for less
heating of the illuminated surfaces than most other conventional
light source devices.
[0044] While light spectrum conversion is known and used in many
applications, this device more efficiently performs the spectrum
conversion to produce light over most of the ONIR range with unique
spectral results, provides a unique spectrum conversion structure
using new materials in a novel way, and also provides additional
light exposure control options and/or heat management structures.
These device embodiments and methods are uniquely suitable to
medical and other biological applications, but also suitable for
non-organic applications. The invention provides examples of
several embodiments of the invention, as well as related
components, systems, and methodology.
[0045] In one aspect, the disclosure relates to a light emitting
device for generating a predominantly non-coherent output light,
comprising one or more spectrum converters, one or more LEDs, and
one or more power supplies arranged for energizing the one or more
LEDs, wherein the device is configured to produce the output light
with an output photon flux that is predominantly in the
orange-to-near-infrared (ONIR) 595 nm-860 nm spectral range, and
with light energy at all wavelengths within such ONIR spectral
range, wherein the light emitting device is characterized by the
following characteristics: (a) one or more of the LEDs are overlaid
with one or more spectrum-converting fluorescent and/or
phosphorescent containing materials or photonic spectrum-shifting
structures, as said spectrum converters; (b) spectrum converting
LED light sources in the light emitting device are configured to
contribute over 25% of the total output radiant light power of the
output light; (c) quantum yield of spectrum converters averages
over 60% when independent of the light emitting device and under
optimal conditions; (d) one(s) of the one or more LEDs to be
spectrum converted provide dominant spectral emission peaks between
350 nm and 480 nm and/or between 600 and 780 nm; (e) 350 nm and 480
nm dominant peak LEDs with spectrum converters use a phosphor or QD
as the spectrum converter for absorption of over 70% of the LED
radiant power light; (f) 600 nm-780 nm dominant emission peak LEDs
with spectrum converters use a fluorescent dye or QD spectrum
converter for absorption of over 30% of the LED radiant power
light; (g) over 70% of the total output light from the device is in
the 595-960 nm spectral range: (h) at least 1% of the highest
radiant power peak in the 600 nm-750 nm part of the emitted light
spectrum of the output light is provided at all wavelengths between
600 nm and 820 nm; (i) LED(s) of the one or more LEDs, whose light
is not significantly absorbed by the spectrum converters comprise
LEDs with dominant peak wavelengths within the 350 nm-480 nm
spectral range and/or within the 650 nm to 860 nm spectral range;
(j) the device comprises a lighted window at which the light output
is emitted, and the device emits at least 0.01 mW/cm.sup.2 average
radiant power output in a primary lighted portion of the lighted
window and the primary lighted portion of the lighted window
comprises a lighted area of at least 4 cm.sup.2; (k) at least 20%
of the primary lighted portion of the lighted window contains over
30% light reflective surfaces at the highest spectral emission peak
of the output light, to reflect light back into the output light;
(l) LED light is provided by at least one of the one or more LEDs
behind the lighted window, in the perimeter of the lighted window,
or brought to the lighted window using fiber optics: (nm) a thermal
controller is arranged to interrupt or reduce power from the one or
more power supplies when temperature of or in the device exceeds a
predetermined value; and (n) wherein when the LED light is not
brought to the window by fiber optics, the thermal controller is
effective to prevent temperature of the device from exceeding
60.degree. C. after 60 minutes of device operation in a 35.degree.
C. ambient environment.
[0046] In another aspect, the disclosure contemplates an LED array
light source comprising channels arranged for peristaltic air
pumping when the light source is bent and/or moved to increase
convection flow in and out of the channels to effect heat removal
from the LED array.
[0047] The disclosure also contemplates a method of light therapy
treatment of a subject in need thereof, said method comprising
generating a modified light spectrum output using a device
according to the present disclosure, and exposing a body region of
the subject to the light output thereof.
[0048] Other aspects, features and embodiments of the disclosure
will be more fully apparent from the ensuing description and
appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0049] FIG. 1 is a top perspective view of a light therapy module
according to one embodiment of the present disclosure.
[0050] FIG. 2 is a disassembled bottom perspective view of the
light therapy module of FIG. 1.
[0051] FIG. 3 is a schematic cross-sectional elevation view of a
light therapy module according to another embodiment of the
disclosure.
[0052] FIG. 4 is a cross-sectional elevation view and a top plan
view of an electric field or magnetic powered bellows cooling
assembly for an LED lighting device, according to another
embodiment of the disclosure.
DETAILED DESCRIPTION
[0053] The present disclosure relates to a multispectral light
source having utility for light therapy and other applications.
[0054] LEDs, as such term is used herein, should be understood to
mean both non-coherent diodes and laser diodes. LEDs and laser
diodes are collectively referred to as LEDs herein. Although the
disclosure is directed to multispectral light source devices
including spectrum-converted LED arrangements, it will be
understood that non-converted LEDs may be employed in such devices,
within the broad scope of the present disclosure.
[0055] Although certain embodiments of the invention will be shown
and described in detail, it should be understood that various
additional changes and modifications not specifically described
herein may be made without departing from the scope of the
invention described herein. The scope will in no way be limited to
the number of constituting components, the materials thereof, the
shapes thereof, the relative arrangement thereof, etc., and are
disclosed simply as examples of embodiments.
[0056] As used herein, the following technical terms have the
following meanings:
[0057] "nm" means Nanometers (10.sup.-9 meters length).
[0058] "OCST" means other color shifting technologies, including
photonic crystals, QDs, photonic spectrum converting fibers,
photoluminescent fibers, and/or crystal arrays or matrices
including combinations of these and other color converting
technologies.
[0059] "PDT" means Photodynamic therapy or the use of light as part
of a therapy of diagnostic. In this document we will only refer to
PDT as light therapy using photosensitizers.
[0060] "Photoluminescent" means any characteristic where light of
one spectral range is first absorbed by a material, and then all or
part of this absorbed energy is later emitted to provide a
different spectrum of wavelengths. This term includes both
fluorescence and phosphorescence.
[0061] "PS" means photosensitizer, a compound or particle that
absorbs light and initiates or engages in chemical reactions using
the light energy.
[0062] "Reporter" means photoluminescent compounds or particles
that absorb one spectrum of light and emit another spectrum of
light, generally used to assess the presence and/or concentration
of a photoluminescent material and `report` this information to
optical sensors (or acoustic sensors if photo-acoustic reporters
are used).
[0063] Quantum yield means the ratio of emitted photons/absorbed
photons from a material for a specific excitation spectrum. It is
shown as percentage without units.
[0064] ".di-elect cons." means extinction coefficient in M-1 cm-1.
"Extinction" shown as the symbol epsilon (.di-elect cons.) refers
to the probability of a dye or other material absorbing photons at
a specific wavelength. A higher number means a high probability of
absorbing photons at a wavelength. If a reference wavelength is not
explicitly referenced, it is assumed that the extinction
coefficient refers to the maximum major extinction or absorption
peak that is shorter wavelength then the maximum emission peak for
the photoluminescent material. "Extinction" does not directly apply
to some materials even though all the photoluminescent materials
exhibit similar photo-optical characteristics, so "effective
extinction" may be referred to in some relative context
references.
[0065] "ONIR" means Orange to Near-Infrared spectral range light
(595-860 nm) While many people consider near infra-red light to
extend past 900 nm, we have confined the ONIR range for the
specific applications herein to be 595-860 nm.
[0066] "IR" means Infrared: Light in the spectral range above 860
nm.
[0067] "NIR" means Near-infrared: Light in the 720-860 nm range
(slightly visible to most people even at moderate intensities).
[0068] "Red" means 620-720 nm light.
[0069] "Orange" means 595-620 nm light.
[0070] "RNIR" means red to near-infrared spectral range light
(620-860 nm).
[0071] "UV" means ultraviolet light with wavelengths in the 100-400
nm range.
[0072] "UVA" means ultraviolet light with wavelengths in the
315-400 nm range.
[0073] "UVB" means ultraviolet light with wavelengths in the
280-315 nm range.
[0074] "VIO" means Violet to orange spectral range light (385-620
nm).
[0075] "VIB" means violet to blue spectral range light (385-490
nm).
[0076] "VIY" means violet to yellow spectral range light (385-650
nm).
[0077] "Violet spectral range" means 385-435 nm.
[0078] The present disclosure contemplates a light emitting device
combined with a spectrum converter and power supply to provide a
primarily non-coherent output light source that efficiently
generates and provides customizable spectral range light.
[0079] In one aspect, the disclosure relates to a light emitting
device for generating a predominantly non-coherent output light,
comprising one or more spectrum converters, one or more LEDs, and
one or more power supplies arranged for energizing the one or more
LEDs, wherein the device is configured to produce the output light
with an output photon flux that is predominantly in the
orange-to-near-infrared (ONIR) 595 nm-960 nm spectral range, and
with light energy at all wavelengths within such ONIR spectral
range, wherein the light emitting device is characterized by the
following characteristics: (a) one or more of the LEDs are overlaid
with one or more spectrum-converting fluorescent and/or
phosphorescent containing materials or photonic spectrum-shifting
structures, as said spectrum converters; (h) spectrum converting
LED light sources in the light emitting device are configured to
contribute over 25% of the total output radiant light power of the
output light; (c) quantum yield of spectrum converters averages
over 60% when independent of the light emitting device and under
optimal conditions; (d) one(s) of the one or more LEDs to be
spectrum converted provide dominant spectral emission peaks between
350 nm and 480 nm and/or between 600 and 780 nm; (e) 350 nm and 480
nm dominant peak LEDs with spectrum converters use a phosphor or QD
as the spectrum converter for absorption of over 70% of the LED
radiant power light; (f) 600 nm-780 nm dominant emission peak LEDs
with spectrum converters use a fluorescent dye or QD spectrum
converter for absorption of over 30% of the LED radiant power
light; (g) over 70% of the total output light from the device is in
the 595-960 nm spectral range; (h) at least 1% of the highest
radiant power peak in the 600 nm-750 am part of the emitted light
spectrum of the output light is provided at all wavelengths between
600 nm and 820 nm; (i) LED(s) of the one or more LEDs, whose light
is not significantly absorbed by the spectrum converters comprise
LEDs with dominant peak wavelengths within the 350 nm-480 nm
spectral range and/or within the 650 nm to 860 nm spectral range;
(j) the device comprises a lighted window at which the light output
is emitted, and the device emits at least 5 mW/cm.sup.2 average
radiant power output in a primary lighted portion of the lighted
window and the primary lighted portion of the lighted window
comprises a lighted area of at least 4 cm.sup.2; (k) at least 60%
of the area of the primary lighted portion of the lighted window
contains over 30% reflective surfaces at the highest spectral
emission peak of the output light, not including area used by LEDs
or spectrum converters, to reflect light back into the output
light; (1) LED light is provided by at least one of the one or more
LEDs behind the lighted window, in the perimeter of the lighted
window, or brought to the lighted window using fiber optics; (m) a
thermal controller is arranged to interrupt or reduce power from
the one or more power supplies when temperature of the LED heat
sink or the LEDs in the device exceeds a predetermined value; and
(n) wherein when the LED light is not brought to the window by
fiber optics, the thermal controller is effective to prevent the
skin or tissue facing side surface temperature of the device from
exceeding 70.degree. C. after 60 minutes of device operation in a
35.degree. C. ambient environment. Lower temperature values can be
selected.
[0080] Optional features such as heat sinks can be applied to
specific embodiments, as well as other optical elements such as
diffusers, gratings, lenses, filters, and light sensors.
[0081] In the device of the disclosure, the spectrum converters may
comprise a phosphor, fluorescent or phosphorescent dye, and/or
quantum dots with substantial light absorption in the under 480 nm
spectral range, and/or a fluorescent dye or photonic crystal
structure with the majority of its absorption spectrum in the under
650 nm spectral range, and where over 70% of light emission from
the spectral converters is within the 595 nm to 960 nm spectral
range.
[0082] The device may be configured as comprising rows or columns
of said LEDs on one or more flexible circuit connection backing
arrangements, and/or comprising a multiplicity of rigid LED modules
that can be placed so as to provide therapy light from two or more
angles. LEDs may be arranged linearly as one or more rows on
flexible circuit strips with reasonable backside heat removal
capability. These types of flexible circuit strip modules are
common in the market for standard. LEDs, but require custom LEDs
and also require PCBs with backside heat removal if true
therapeutic light radiance is desired for less than 1 hour
exposures of joints in body parts larger than fingers. LEDs may be
arranged as small rigid linear or 2D circuit board, metal, or
ceramic blocks and connected to that function like a tank tread.
These types of circuit modules are common in the market for
standard LEDs, but require custom LED processing. LEDs may the
arranged in medium or large rigid arrays. These arrays may be
organized like tanning beds or put on racks to expose the body from
one or more sides. Many design arrangements exist or are
possible.
[0083] The device may be configured, as comprising control
circuitry configured to operate the device at a constant luminance,
or modulated at one or more frequencies and at one or more duty
cycles. Modulation frequencies between 6 Hertz and 20K Hertz may be
used for direct light therapies. Modulation frequencies between 20K
Hertz and 110M Hertz may be used for driving photoacoustic imaging
or therapeutic processes.
[0084] In various embodiments, the device may comprise a backside
heat sink structure comprising heat conducting belt loops
configured to dissipate at least 25% of the total heat load from
the one or more LEDs and/or comprising sections of heat conducting
belts in contact with said belt loops, e.g., heat conducting belt
loops that can dissipate at least 25% of the total heat load from
the LEDs. This heat sink structure may be flexible or rigid. Any of
many effective and well known heat transfer coupling methods the
LEDs to the backside heat radiator may be used such as thermal
conducting silicone adhesives or silicone tape and other thermal
conductors known to fill or conform to gaps between surfaces such
as thermal conducting grease. Materials of construction can be
almost any environmentally stable, safe to use structurally
adequate as a belt or belt loop heat conducting material exhibiting
over 0.1 W/mK thermal conductivity such as many metals, composite
materials such as polymer encapsulated graphite or carbon fibers,
or polymers with heat conducting additives.
[0085] The device may comprise a backside heat sink structure,
e.g., a structure that permits air flow around and/or through a
backside radiator that includes four or more heat conducting
materials formed as fins, waves, tubes, or folds bonded to a heat
conducting base structure. The baseplate of the heat sink structure
may be mostly flat, or have its own structure such as secondary
waves, ridges, fins, grid including a wire or strip grid, and/or
embossing of any design. The folds or waves may be square,
triangular, trapezoidal, cylindrical, rectangular or
semi-rectangular tubes, curved, wave-like, have flat top or
bottoms, or almost any other shape that provides an air path under
or under and/or through the heat sink structure and a reasonable
thermal connection to the base plate or through an alternate
overall underlying thermal path to the LEDs (such as a thermal
conducting thermal adhesive or grease protruding through a mesh
baseplate to the heat radiators). The folds or waves may be
repeating or be a mixture of shapes. Multiple layers of the folded
wave structure may be superimposed or interdigitated. The folded
heat sink appearance may be derived from actually folding the
material or by forming or molding the material into a similar
structure.
[0086] For all of these backside or perimeter of the thermal module
heat sinks, the heat sink structures may be optionally painted,
embossed, brushed, anodized, and/or polymer coated. These heat sink
structures must be thermally connected each other or to the LED
modules in a way to allow sufficient heat transfer to occur.
Braising, gluing, clamping, stapling, clamping with thermal grease
or other thermally conductive bonding are acceptable if appropriate
materials are selected. These heat sink structures may be made from
almost any reasonably thermally conductive, environmentally stable
and safe to handle metal such as aluminum or an aluminum alloy,
plated copper, and/or laminated metal such as aluminum laminated
over copper. Metal can be cast metal (sectioned blocks, linked
together in some way or thin enough between sections to bend, sheet
metal (single or multiple), folded sheet metal, perforated metal
sheet metal, or wires bound together in a screen of any
arrangements or be placed in a parallel orientation, and/or any
combinations of these and other heat conductor arrangement. These
heat sink structures may be a non-metal such as polymer encased
graphite, thermally conductive silicone with carbon fibers, metal
filling, alumina or diamond particle filling, and/or other thermal
conducting materials. Combinations of heat sink materials are
permitted as long as the base material conduction heat from a
thermally conducting interface between the LEDs and the base
material to the heat conducting waves or an underlying heat
conducting material transfers heat efficiently to the heat
radiating folds or wave structure. Fans, thermoelectric coolers,
pumped liquid through a recirculation system and through heat
exchangers, or forced air cooling through tubes and through the
device (with or without refrigeration of the air), and other
well-known cooling methods may be optionally used to further
enhance heat removal in situations where the ability to remove heat
locally is restricted or undesirable. Multiple rigid modules may be
linked together to form pods that can be organized into linear or
2D arrays than can then be shaped into 3D arrays such as whole or
partial cylinders to go around body parts or people.
[0087] The device may be constructed, wherein the lighted window
comprises one or more windows on a top side of the device where the
light output is emitted, wherein: the active-light window area in
front of the LEDs has one or more translucent windows providing:
low thermal conduction to the skin or other tissue, comprising a 2D
or 3D matrix of liquid, gel, or air filled gas pockets or channels,
and comprising low-thermal conducting top surface materials; air or
gas is flowed through the pockets or channels to improve heat
removal; bumps and/or raised patterns and/or recessed patterns are
disposed between two or more transparent layers between be one or
more LEDs and the windows; bumps or fiber-like extensions of
surface material, or a matrix of LED coupled fibers protrudes
through a window; a top outer surface of a window comprises a grid
of wells to provide air pockets to reduce heat transfer through the
windows and/or to hold materials for application to the skin;
and/or the lighted window is formed of a low index of refraction
silicone or multiple layers of low index of refraction coatings or
films are provided at a surface of the lighted window.
[0088] The light source device may thus be provided with one or
more windows on the topside of the device where light is emitted
where: the active-light window area in front of the LEDs has one or
more translucent windows providing low thermal conduction to the
skin or other tissue, consisting of a 2D or 3D matrix of liquid,
gel, or air filled gas pockets or channels, and the use of
low-thermal conducting top surface materials such as translucent
soft silicone; air or gas may optionally flow through these pockets
channels to improve heat removal; bumps and/or raised patterns
and/or recessed patterns such as rows, columns, and/or grids
(horizontal and vertical grid heights can be the same or different)
between 2 or more transparent layers between the LEDs and the
surface of the window may also or alternatively be used to reduce
heat transfer from the LEDs to the front surface; bumps or fiber
like extensions of the surface material, or a matrix of LED coupled
fibers protruding through the top window to direct light through
hair to skin as an option; the top outer surface of the window that
would rest against the skin may have a grid of small wells
approximately 0.5-20 mm in length or width and 0.1-10 mm deep to
provide an additional layer of air pockets to reduce heat transfer
through the transparent window and/or to hold emoluments, gels,
liquids, index mating materials, drugs including photosensitizers,
or other materials against the skin; and/or the top window may be
made of low index of refraction silicone or use multiple layers of
low index of refraction coatings or films at the interface of the
skin and the window to improve light transmission into the skin.
This includes the use of removable films such as oils or waxes and
other coatings on the window or skin to provide a stepped index of
refraction and closer coupling index of refraction with that of the
skin (.eta.=1.35-1.42 range).
[0089] In another aspect, the disclosure contemplates an LED array
light source comprising channels arranged for peristaltic air
pumping when the light source is bent and/or moved to increase
convection flow in and out of the channels to effect heat removal
from the LED array. This may be used to assist front side and/or
backside heat removal. The light source may be fabricated so that
underneath the window-like surface structure and part of the same
molded part is an array of transparent vertical polymer (e.g.,
silicone) walls that are laid out in a matrix so that the underside
vertical walls of the silicone meet with and partly seal over the
LED strips that are recessed into the bottom thermally conducting
silicone. This array acts like an airgap insulator between the heat
producing LED arrays the patient. However, even with good heat
sinking out the backside, the air in these pockets can become
heated.
[0090] The sides of wells in one direction may have a partial
opening in the short direction across the array when not
compressed, but that opening has a silicone flap on one side of
each air pockets' door. However, there is a flap is positioned on
one side of each wall covering the door. When the pockets are
compressed, air pushes on the flap side of the door and seals it
seals tighter. The flap opens when pushed away from the wall,
thereby creating check-valve pathways that transfer air
preferentially along the short direction of the rectangular
structure. When pressure is released, air is pulled in from the
other side. Therefore the hot air is forced out when compressed,
but then pulls cool air back in when release like a diaphragm. The
flow directions alternate left and right for every other channel
along the array of air pockets. If over compressed quickly, the
bottom wall seals release so air just goes out in all directions so
the pockets are kept safe from bursting: under reasonable operating
conditions.
[0091] In other embodiments, the device comprises a monitoring and
control assembly including one or more light sensors placed in, on,
and/or near the lighted window, facing toward a target surface when
the device is in use so that the sensor(s) detect reflected light
from the target, with the sensor(s) arranged to provide input to a
controller circuit to adjust flight intensity based on
reflectivity, and/or to adjust the time of treatment. When one or
more light sensors are placed in, on, and/or near the window of the
LED array, facing toward the illuminated skin surface, the
sensor(s) detect reflected light from the target. These sensor(s)
provide input to a controller circuit to adjust the light intensity
based on tissue surface reflectivity at the wavelength ranges being
used, and/or to adjust the time of treatment. Multiple sensors
sensitive to different wavelength ranges can be used for the
detection of preferential reflected wavelengths of light and to
permit manual or automatic adjustment of relative power to the
mixture of different color LEDs.
[0092] Several common types of sensors may be made sensitive to
specific wavelengths. Silicon sensors can be used so that multiple
types of sensors may be packaged together. Optical filters may be
used to allows sensors to preferentially detect spectra of
interest. Example filters are available from many suppliers for
specific notch wavelengths and for short pass or long pass filters
include interference filters, gratings, and absorbing film filters,
among others. Examples using a spectrum providing a 410 nm emission
peak, a 650 nm emission peak, and a 810 nm emission peak be short
wavelength pass filters for below 420 nm, for 630 nm-680 nm, and a
long pass filter for above 780 nm. These sensors can also provide
and record data on the tissue or skin reflectivity at the
designated wavelengths or wavelength ranges.
[0093] The device can comprise a monitoring and control assembly
including one or more temperature sensor(s) that are arranged to
directly or indirectly monitor a target surface temperature, e.g.,
skin temperature, and provide corresponding input to a controller
configured to modify light intensity and/or treatment time of the
device. These sensors provide information to a controller that can
be used to modify the light intensity and/or treatment time as
directed by the treatment clinician, physician, or by a
predetermined formula in the controller or computer linked to the
system. Infrared light sensors may be used and placed in or near
the LED array, facing toward the target of the illumination that
detects the temperature the target, provided a sensor is selected
that is not affected by this light source's wavelengths. Many such
products are commercially available. Surface contact thermocouples
and/or other surface contact based temperature sensors may be used
to monitor skin or tissue temperature. Likewise, either type of
temperature sensor may also and/or alternatively be used for
sub-dermal temperature measurement.
[0094] The device may be configured with the LEDs are positioned
toward bundles of fiber optic loops or coils to concentrate light
in a forward direction and comprising phosphors, quantum dots,
fluorescent or phosphorescent dye, dye-doped fibers, and/or
photonic crystal fibers to provide spectrum conversion. Coherent
fiber laser light sources may be created.
[0095] The device in embodiments may be configured as comprising
one or more piezoelectric, capacitive, inductive, or
magnetostrictive transducers or motors to generate sonic and/or
ultrasonic energy and/or vibration from, and/or the vicinity of the
output light as continuous and/or pulsed energy.
[0096] The light source may be constituted in embodiments to
include electrodes to provide pulsed. AC current to stimulate
tissue surface and tissue locally under and near the light
source.
[0097] In other embodiments, the light source may include 2 or more
over 5 gauss magnets that can be permanent and/or electromagnets.
Such magnets may be changed in polarity or positioned as desired
mechanically or electrically. One or more electromagnets may
additionally or alternatively be used and pulsed.
[0098] The light source device in embodiments may comprise one or
more controllers that are programmably arranged to turn the device
oil at an end of a programmed time. Such controllers may be either
imbedded and/or attached to the system and desirably can be
programmed and turn the system off at the end of a programmed time.
Over temperature switches may be provided and connected in series
to turn the system power off in the event of overheating at 1 or
more locations in the unit. One or more controllers may also
optionally: turn off or on all or adjust the power to prewired
portions of the LED array (modes) at designated times or resulting
from other selected conditions being met; adjust the treatment time
or power and mode conditions based on input from various light
sensors monitoring parts of the patient's skin's reflected light
spectrum, the patient skin or tissue temperature under the light,
or other patient parameters; control any accessory features such as
magnetism, TENS, and vibration; notify the patient and/or page a
clinical attendant when the treatment time is about complete, or if
certain selected conditions are met, or certain system failures
occur. The patient may also turn off the system and page the
attendant. The controller may communicate to one or more computers
or databases. Other functions may be built in, e.g., preprogrammed
functions including easy operation controls for home use without an
attendant.
[0099] The disclosure also contemplates an LED array light source
comprising channels arranged for peristaltic air pumping when the
light source is bent and/or moved to increase convection flow in
and out of the channels to effect heat removal from the LED
array.
[0100] The light source device of the disclosure may comprise a
cooling system configured to pump or suction air through an
interior region of the device and/or for air over a heat sink in
the device, and/or a water recirculation heat exchanger.
[0101] The device in various embodiments may comprise a diaphragm
or bellows air pumped cooling system. The light source may use a
diaphragm or bellows air pumped cooling system for a flexible LED
array comprising multiple LEDs mounted on a flexible printed
circuit board (PCB) with heat-conductive material under and/or
around each LED to provide a heat transfer to underlying heat sinks
using, brazing, solders, or eutectic bonding, conductive composite
materials, low melting point metal alloys, thermally conductive
grease, and/or thermally conductive adhesive materials. A heatsink
may be provided, comprising a thermally conducting material such as
graphite, metal such as aluminum, plated or laminated metals,
thermally conductive composites such as thermal conductive silicone
or flexible carbon fiber, diamond particles, or metal fiber
composites. These heatsink or LED module structures can be arrays
of multiple rigid plates or bars arranged to effectively create a
flexible tiled structure that is held together by webbing, screens,
foil, thermally conductive tape, or other flexible structures.
Multiple layers of these materials may be used. Fins, tubes or
other known heat transfer structures may optimally be used to
increase heat transfer area as long as they do not seriously
interfere with the device operation.
[0102] A cooling system may be provided comprising a flexible
molded or assembly of sheet material such as silicone or other
polymers on the backside opposite the LEDs. This structure will
have one of more electrical conductors in or on the polymer
structured to perform as a bellows. The electrical conductor sheets
to be covered or be coated with an insulating material to be
minimally vertically conductive, and/or the opposing heat sink
surface should be covered or coated to be minimally electrically
conductive vertically. The heat sink or conductor placed over the
heat sink may be used as a second electrode.
[0103] Standoffs may be provided between each pair of electrical
conductors, placed periodically so that the plates generally remain
apart unless forced together. These standoffs can be formed when
molding one of either side of the bellows or added to the structure
to the gap as separate components. An electrical change may be
placed between these plates creates an electric force that can pull
the plates together and push air out and when release they can pull
air in.
[0104] The bellows may be one or more large or long sections that
can push most of the air out from between the conductors, can be a
series of bellows that sequentially are activated by a controller
to push air linearly in any selected direction, and/or can be
configured as one or more smaller diaphragms or bellows that push
part of the air in one direction due to check values built into the
air part so air travels primarily in one direction for each
channel.
[0105] If check value are used, they can be prefabricated and
inserted into the channels during assembly, or the check values can
be made as part of the structure when one or both sides of the
channel are molded. The check vales may be simple flaps with a
preferred direct and be blocked from reversing direction with
molded in ridges. High dielectric constant materials such as
epoxy/barium titanate coating composites are preferred over these
conductor plates to reduce the required voltage. Magnets,
conductive coils, and/or ferromagnetic materials may be substituted
for the electrically conductive plate to provide an alternate
motive force to these bellows. The device can also be configured
with the chambers operating in the opposite polarity by the
repelling the top and bottom walls of the chamber if the chambers
are in a normally compressed state. This structure can be revised
for lateral force driven pumping. Electrically controlled
constricting or sheets fibers may also be used to compress or
expand the diaphragm.
[0106] The disclosure also contemplates a method of light therapy
treatment of a subject in need thereof, said method comprising
generating a modified light spectrum output using a device
according to the present disclosure, and exposing a body region of
the subject to the light output thereof.
[0107] The method may be conducted, wherein the light therapy
treatment is carried out to treat: joints and muscles for reducing
pain and inflammation: wounds for improving the rate of wound
healing; acne, rosacea, skin tone, and other dermatological
conditions, to improve healing, and reduce the population of
bacteria or fungus that are directly or indirectly photosensitive
to the light spectrum of the light therapy treatment; muscles for
enhancing regeneration of tissue after exercise or other stress;
bone areas to repair damage and improve bone density; head, neck,
spine, or other body areas, for pain and inflammation, for mood
treatments, for reducing damage from brain injuries, or for
increasing generation of nerve stem cell; veterinary subjects;
photochemicals from food, herbs, and/or photochemical drugs for
phototherapies; plants to enhance plant or algae growth or to
control other plant functions selected from the group consisting of
ripening, seed formation, and bud formation; or water and other
fluids to activate photosensitizers for purification and/or
antimicrobial and/or other pathogen treatments.
[0108] The method may be carried out to use a large area light
source (area over 50 cm.sup.2) an area anywhere on the body using
bracketed mechanical systems, straps, or adhesives, and/or other
methods to keep the light source positioned correctly for a period
of time. In all drawings hereinafter described, the textual
portions of such drawings is to be regarded as set forth in this
description, as incorporated in such description by reference.
[0109] An example of one simple overall embodiment if this light
therapy module is shown in FIG. 1. FIG. 2 provides a partial
disassembly of this example light therapy light source. In this
specific example embodiment, an assembly of flexible molded
components (e.g., silicone rubber) holds heat sinks, silicone
peristaltic air baffles, arrays LEDs with spectrum converting
materials, and temperature limiters together. Not all aspects of
this invention are depicted in this example. Microcontrollers and
power supplies that attach externally and their optional wires are
not shown. This simple spectrum converter example would emit a
light spectrum with emission peaks 447 nm, 655 nm and at 835 nm,
but unlike other light therapy systems, this system with only 2
type LEDs will also provide significant radiant power at all
wavelengths between 440 nm-460 nm and between 590 nm-860 nm. In
this example, light is emitted from the array of small window-like
structures facing upward. The entire interior window array of small
wells is all translucent silicone. These wells can hold lotions,
gels, drugs, and/or refractive index matching materials next to the
skin. There is also an array of larger size air pockets below these
wells which act to reduce conduction heat transfer to the skin of
the patient. Heat is easy to add or allow to increase, but a
challenge to remove in small passive system with one side
potentially pressed against the body without adding fans, blowers,
pumps, and other additional features.
[0110] In the example provided in FIGS. 1 and 2, rows of a 120
high-power LEDs (.about.27 W power input at 12VDC or 24VDC) on
flexible strips are longitudinally placed under these wells, and
are therefore not visible in this view. Holes in the sides allow
air to flow in and out of the interior of the structure to remove
heat. Any bending or compression movements by the patient
compresses the interior pockets and pushes warm air out, and then
cooler air is pulled back in when pressure is released. However,
the main heat removal radiators are located on the back side of the
system that is better seen in FIG. 2. The backside of the light
patch including the belt loops and optionally also the belt itself
are all thermally conductive and help spread the heat over a large
area for easy transfer to the air. Around the top perimeter of the
device is shown an optional soft and flexible opaque lip that
provides a soft surface against the skin and allows horizontal air
flow when not pressed tight against the skin. This lip can flatten
and allow the array of window-like wells to be pressed onto the
skin if desired. This lip also blocks light leakage, which could
potentially be annoying to users because of the very high light
intensities this system provides. The light source contains a type
of spectrum converters that have not been associated with this
application and effectively uses extraordinarily high phosphors
concentrations that are not considered practical along with novel
concepts in backside heat sinking, forward heat control buffers,
and peristaltic assisted hot air removal from the interior of the
module. All of these are necessary for a good working device. In
other embodiments of this invention herein, including the novelty
aspects of the new spectrum converters are provided. The present
device is a primarily non-coherent light source with over 70% of
the output photon flux in the orange-to-near-infrared (ONIR) 595
nm-860 nm spectral range, where there are one or more high quantum
yield (internal QY over 60%) spectrum-converting materials placed
between the LED and the surface(s) to be illuminated, and one or
more light emitting devices or other compatible light generators.
These spectrum converter materials may be separate or be mixed into
a single spectrum converter component.
[0111] FIG. 3 provides a simple diagram showing the function of the
1 and 2 stage spectrum converters. FIG. 3 also shows the concept of
mixed light where not all of the light needs the spectrum
converted. Some therapy lamps may have switchable modes for
purposes permitting some spectral and/or radiance modes to be those
discussed in this document, but other modes may also be possible.
Light source modes supplementing the converted light modes with
significant radiant emission peaks within the 760-860 nm spectral
range are considered very important.
[0112] In the present invention, we will generally use the term
"LED" as a generic acronym placeholder for "Light Emitting Device,"
encompassing all initial solid state light sources. The preferred
initial light sources for most applications are light emitting
diodes (also commonly known as "LEDs") or semiconductor diode
lasers but additional options include but are not limited to other
lasers, organic light emitting diodes (OLEDs), electroluminescent,
and/or other solid state light-emitting devices.
[0113] Other light sources which can also be used as LEDs in all of
the embodiments, include but are not limited to gas lasers, liquid
or gel lasers, solid state lasers, fiber optic lasers,
electroluminescent, cathodoluminescent, halogen lights, gas
discharge lamps, plasma light sources, fluorescent lamps, quantum
dots, and other liquid, gas, vacuum, and/or types of visible or
near-infrared light sources available now or in the future.
[0114] In the present invention, the term "spectrum converter"
consists of one or more photoluminescent materials in a structure
that permits light to be absorbed and re-emitted efficiently. The
spectrum converter can also be called a color converter. These
spectrum converters must collectively convert light emitted by the
to-be-converted LEDs into ONIR light, and the converted light
output must contain photons with wavelengths covering the majority
of the ONIR spectrum (595-860 nm).
[0115] The initial LEDs, LEDs plus phosphors, or other light
generators may be either broad spectrum or narrow spectrum sources,
as long as those light generators to be spectrum-converted can
significantly stimulate the spectrum conversion portions of this
device meeting the photo-luminescent light absorption and emission
criteria described herein.
[0116] In a preferred embodiment of the invention, at least one of
the spectrum converters in each LED with spectrum converters must
provide a larger than 100 nm spread between the longer and shorter
wavelengths where 10% of peak emission intensity occurs. In one
embodiment of the device structure, this can be accomplished using
a single photoluminescent material such as a 650 nm oxynitride or
nitride phosphor, and in another variation this could be
accomplished by using multiple narrow emission spectrum
photoluminescent materials such a matrix of quantum dots converters
with optional phosphors or dyes mixed in and or layered on or over
the device.
[0117] An embodiment of the present invention incorporates use of a
dye as a spectrum converter. In this discussion, we use the term
"dye" to refer to fluorescent or phosphorescent materials that are
mostly distributed at a molecular level in solutions (e.g.,
polymers, sol gels, low temperature glasses, liquids or gels, and
other translucent materials in a wide variety of shapes). Dyes may
aggregate into groups of molecules, remain separate in the medium,
and frequently contain some combination of both dye aggregates and
non-aggregated dye molecules. The definition of dyes in this patent
filing is generalized to refer to all photo-luminescent organic
dyes, organic pigments, primarily organic particles and
nanoparticles, and/or bulk photo-luminescent materials.
[0118] Spectrum converters are not new or unique. However, the
phosphors, dyes, and QDs in this invention are used far outside of
the conventional and published ranges and in this different
applications space and in different configurations with
surprisingly good spectra and light output efficiency results when
used with these classes of converter materials, these LEDs in these
configurations, with this cooling of the devices and materials, at
these thickness, concentrations, input light radiance, and with
these unique spectral input and output objectives. We found that we
only degraded the output QY by about 5-10% if we increased the
color converter thickness by 1.5-2.0 times and increased the
phosphor concentration by 2.5 times what we previously considered
to be upper practical limits. Over 70% light absorption of incoming
blue or violet light by a phosphor or dye in a spectrum converter
requires these very high phosphor layer thickness and
concentrations when compared to conventional uses. It is this very
high >12% total phosphor concentration that is unique and still
provide a reasonably high QY if done correctly.
[0119] The color converter concentrations and % absorption are far
outside the conventional operational modes. Specific reference is
to the practice with nitride and oxynitride 5-25 micron phosphors
on 3528, 2835, 5050, 5056, 1 W, and 3 W under 450 nm dominant peak
emission LEDs We observed an over 10.times. increase in overall
radiance capability per unit area. The 3-way cooling, short optical
path length (<1 cm), airless coupling of light into the tissue,
and with reflectors being just a few millimeters away from the skin
redirecting much of the scattered or backscattered light from the
tissue and skin back into the skin all appear to contribute to the
enhanced capability to deliver red and near-IR light into the
skin.
[0120] We surprisingly found it was possible to obtain as much
light radiance per unit of system cost at good power efficiency in
the specific spectral ranges of interest this way in the 640-720 nm
range as with conventional single color LEDs or lasers, and then we
can use the additional "almost free" orange-to-red 590-640 nm
light, some of the blue and/or violet light, another >720 nm
near-IR energy to really provide multi-purpose system benefits for
both shallow and deep tissue treatments using basically the same
configurations, especially using the free added orange spectral
region.
[0121] Few serious researchers have even tried the color converter
approach for light therapy other than for some relatively low
radiance white light alertness tests (but high-radiance for
"bright" vision is extremely low-radiance for deep tissue light
therapy and the spectral ranges are totally different). This is
because lasers with narrow bandwidths have been preferred for lab
experiments on light therapy, and only in the past few years have
LEDs really started to take hold due to their plunging cost. Also,
multiple recent studies showed similar therapeutic results between
LEDs and laser diodes for many conditions. During the last 2 years,
it has also begun to become apparent that the therapeutic windows
are probably quite wide +/-30-50 nm for several light therapies
(especially for pain and inflammation related that may be as wide
at 640 nm to 900 nm depending on the target depth and treatment
conditions) due to multiple studies providing similar result in
different spectral ranges. Those wavelengths are all included in
this spectrum, and at high radiant intensities. If all of these
wavelengths ranges are really as effective for pain, inflammation,
and accelerating tissue repair, then the radiant total power out of
these new light sources and the radiant power absorbed into the
tissue will make these type devices far more effective, or at least
as effective with shorter treatment times, than anything else
available today even at 10-20 times the cost.
[0122] For Lumogen F 305 dye from BASF and the newer OR
perylene-related class dyes discussed herein, we found that at
0.15-0.50 mm thickness layers at, over 70% absorption could be
achieved with over 85% conversion efficiency and more than
sufficient photostability for these unique type products when used
in conjunction with these phosphor color converted 630-670 nm high
converted light beams at very high radiant light intensities.
[0123] A preferred embodiment utilizes very stable, low cost
organic dyes that are soluble in a variety of polymers that provide
the wide spectral range desired and very-high efficiency emission
in the deep-red to near IR range. These new dyes are perylene
derivatives with peak emission at approximately (depends on medium,
batch, and final operating conditions) 615 nm, 645 nm, 670 nm 775
m, and/or 820 nm. Previously known existing perylene dyes may also
be integrated into embodiments of this new invention, including but
not limited to dyes such as BASF Lumogen Red 305 (600-610 nm
emission peak).
[0124] Another embodiment of the spectrum converter of the present
invention incorporates use of phosphors as the spectrum converter.
This term is generally used to refer to mostly inorganic
photo-luminescent materials (fluorescent or phosphorescent) that
are used as nanoparticles or small particles that appear like a
fine or granular powder before mixing into solutions (e.g.,
polymers, sol gels, low-temperature glasses, liquids or gels, and
other translucent materials in a wide variety of shapes). In this
discussion, for simplicity we generalize the use of "phosphor" to
cover all particle based photoluminescent materials which includes
but is not limited to inorganic phosphors, inorganic
photo-luminescent pigments (e.g. Egyptian Blue), quantum dots,
nanocrystals, and other color converting materials.
[0125] A preferred embodiment utilizes several new violet and blue
light absorbing, deep-red emitting oxynitride or nitride phosphors
that provide part of the desired ONIR spectrum which can work
synergistically with the new organic perylene derivative dyes, and
not just by being additive. The peak emission wavelengths of 2 of
these new phosphors are 650 nm and 670 nm. Variations of these
phosphors with similar spectral characteristics are available from
multiple suppliers.
[0126] In addition, the present invention also incorporates the
optional use of quantum dots or other nanostructural spectrum
converters, to allow further customization to the output light
spectrum for light therapy. Quantum dots are nanoparticles or
microparticles with multiple layers or atoms or molecules around a
core, instead of single composition crystal particles like in most
phosphors or coated phosphors. As photoluminescent materials, they
behave similar to phosphors, but can be more efficient and highly
selected quantum dots of the same structure can exhibit more narrow
emission spectra unless there is a specific reason to separately
refer to QDs. Unless there is a specific reason to separately refer
to quantum dots, quantum dots will usually be incorporated into the
"phosphor" category for most references herein.
[0127] While these quantum dots are narrow spectrum emission and
may be more expensive than other alternatives, quantum dots are
available at several peak wavelengths in the red spectral range,
and multiple quantum dots can be made with a variety of wavelengths
and mixed to create a virtual broad spectrum light source. Using
small amounts of these quantum dots can allow fine-tuning of the
spectrum for the most demanding applications without serious cost
implications.
[0128] The present invention provides for a wide variety of
combinations of phosphors, quantum dots, and/or dyes as
photoluminescent spectrum converters.
[0129] In the present invention, other wavelengths of light may
also be present in the light source output spectrum at up to 15% of
the total output photon flux from the portion of the light source
that converts light into all or a large part of the ONIR spectrum.
Light sources producing other wavelengths, with or without spectrum
conversion, may be used to further supplement the intensity of
selected wavelengths of light.
[0130] The present invention anticipates use of principally-ONIR
spectrum-converted LEDs and mixtures of ONIR spectrum-converted,
non-ONIR spectrum converted LEDs, and non-converted light LEDs.
[0131] The present invention also incorporates a "matrix,"
sometimes referenced as "medium." Either term refers to a material
that is mostly translucent to the absorption and emission
wavelengths of the photoluminescent materials placed in that
material. These medium materials can be coatings, sheets, bulk
materials, molded or otherwise shaped materials, or liquids in a
cavity. These materials may consist of organic and/or silicone
polymers, glasses, crystals, microstructured or nanostructured
arrays, multilayered structured materials, inorganic composites,
inorganic and organic composites, sol gels, liquid crystals, and
many other materials. The medium materials may be in the form of
solids, semisolids, chalcogenides, gels, liquids, liquid crystals,
and/or combinations thereof.
[0132] The thickness of the translucent matrix and spectrum
converter materials in this invention can vary from a micron or
less to up to many centimeters because the optimal and
photoluminescent material concentration thickness depends on the
specific materials selected and the final spectrum objectives in a
specific design. Typical spectrum converter thickness will be in
the 0.1 mm to 5 mm range, unless the converters are in or part of
single or bundled optical fibers where the spectrum converter
material concentrations will typically be lower and the optical
path lengths through the spectrum converters may increase
substantially. It is anticipated that these are design issues that
can be predicted and experimentally adapted for this invention by
engineers or scientists with a basic understanding of
photoluminescent phosphor and dye technologies, published
literature, and by using the concepts presented herein.
[0133] Very thin light spectrum converters may be made using pure
or very high concentration (>70%) layers of dye and/or phosphor
material without a matrix material, or very little matrix material,
as long as the films have uneven surface texture or are
discontinuous to reduce light trapping effects and provided
aggregation of the dye can be controlled as as to not greatly
reduce its efficiency.
[0134] The dye and/or phosphor concentration required to convert a
certain percentage of the input light at a given wavelength and
intensity reduces almost proportionally within a given converter
matrix volume.
[0135] The type of matrix used to contain a dye can change the
stability, absorption, and emission spectra, or even quench the
photoluminescent properties. While typically less pronounced,
optical characteristics of phosphors, quantum dots, and other
spectrum converters can also be affected by different medium. Other
materials discussed can work together, but may require different
thicknesses and concentrations or other additives. Multiple types
of dyes, phosphors and other spectrum converting materials in a
matrix can interact, effecting relative concentrations, stability,
photoluminescence and other optical or physical
characteristics.
[0136] Organic dyes can offer less scattering losses because they
can be mostly distributed at a molecular level, and can provide
higher quantum yield than most phosphors. Lower concentration of
dye in proportionally thicker films tends to reduce aggregation
risk and improve conversion efficiency and photostability. Thicker
converter medium are heavier and tend to be less flexible.
[0137] A preferred structure of the invention is provided where the
photoluminescent materials in the spectrum converters are arranged
so the "converted-spectrum" light exiting one spectrum converter
has a predominantly longer wavelength spectrum than the absorption
spectrum of the spectrum converter the light then enters.
Therefore, primarily unconverted light passing the first converter
is absorbed and converted by the second converter, thereby
providing higher overall energy efficiency. This structure can be
applied to 2 or more sequential color converters.
[0138] Another preferred embodiment is that the spectrum converters
following the first color conversion pass through a minimally
scattering spectrum converter such as a dye or quantum dot.
[0139] Another preferred embodiment of the structures in this
invention is that a matte surface texture, other surface patterns
or textures (arrays of mini or micro lenses, basketball-like bumpy
surfaces, or other surface modifications), or structural
discontinuities in the spectrum converters be provided to minimize
light channeling and capture related losses in the spectrum
converters.
[0140] Index matching materials can be placed between sequential
spectrum converters for eliminating air gaps between the spectrum
converters and between other layers of translucent material the
light path is expected to pass through can be used to reduce light
coupling losses. Also, under 1.5 refractive index soft translucent
silicone (at or under 30 Shore) can be pressed against the skin or
other tissue to provide enhanced light coupling.
[0141] The use of reflectors around and between the LEDs should be
used to redirect light toward the surface to be illuminated.
[0142] One embodiment of the invention is a light therapy device
consisting of multiple layers of all closely index of refraction
matched phosphor and/or quantum dot and/or nanoparticle color
converters, as previously described, that also matches the
refractive index of human or animal skin. The embodiment can also
be soft and conformal.
[0143] The use of index coupling materials in contact with the skin
can further increase the light transmission into the skin, as can
minimizing the occurrence of air gaps between the skin and light
source. The nominal index or refraction of living skin for the
650-850 nm range, even taking racial or heavily tanned skin pigment
differences into account, is approximately 1.4. Extreme index of
refraction variations still tend to still be within the 1.33-1.44
range. Several solutions can be used for index matching including
.about.25% gelatin-water mixtures, .about.30% glycerine water
mixtures, .about.35% sugar (e.g., sucrose): water mixtures, and
several oils. Silicone gels have recently become available that can
be customized to a wide range of refractive indices including 1.40,
and these are non-liquid, highly-conformal and contact safe
materials.
[0144] The present invention specifies that the use of the
customized 1.4 refractive index silicone material (or other 1.4
refractive index polymers) used as a matrix materials for phosphor
and/or quantum dots spectrum conversion materials can be close to
an index of refraction of 1.4+/-0.5, to minimize light losses due
to refractive index changes from the exit of the LED to the skin.
Minimal losses due to air spaces between the light therapy device
and skin can also be achieved with a conformal or body contoured
light source device like those described in this patent application
and soft silicone gels. Translucent, food grade, silicone with
hardness under Durometer 20 is preferred for the portion of the
silicone facing the skin, unless pressure is used to compress the
light therapy devices against the skin, an index matched liquid or
gel interface to the skin is provided, or a body shaped rigid
material, such as low index glass, is used.
[0145] Selecting thin, low index of refraction polymer for the dyes
and having only a single transition in and out of one color
converter with minimal occurrence of air gaps in the light path is
also a viable energy efficient structure.
[0146] The LEDs in this application are considered to be discrete,
although OLEDs and electroluminescent devices could be fabricated
as 2D panels. Many discrete LEDs can be laid out to form 2D arrays.
The LEDs can be a screen matrix layout, serpentine layout, and/or
formed as multiple rows and/or columns of LEDs.
[0147] For rectangular and many other shape 2D LED arrays, rows of
LEDs laid out as linear strips are a preferred embodiment. (2836,
5050, 5060, or 3528 light emitting diodes are examples of LEDs that
can easily be surface mounted onto flexible printed circuit boards
strips using automated equipment at low cost.) These LED strips can
be connected at the ends and powered at low voltages. A typical LED
strip drive voltage is 12VDC, but other LED strip drive voltages
can be purchased or designed. The number or LEDs per 10 cm length
of LED strip can be varied, although 12 LEDs per 10 cm long 3528
strip or 6 LEDs per 10 cm long by 1 cm wide 5050 LED strips are
considered standards. Twice this number of these LEDs per unit
length are now commercially available (e.g., 120 5050 LEDs/meter
for about 27 W/meter.).
[0148] LED strips are frequently coated with translucent silicone,
polyurethane, or epoxy to be made more waterproof. The preferred
invention provides that these coatings can be made using customized
.about.1.40 index of refraction silicone gel, and that
photoluminescent phosphors or quantum dots can be placed within
that matrix. 0.46 to 0.56 index of refraction polyurethane is also
a good choice in this invention that is very low cost, but with
poorer light transmission coupling into the skin. Other LED coating
materials exist or are being developed that could be substituted,
and materials can be layered to provide step graded index where the
bulk coating material could be low cost, but then multiple layers
of different thinner material coatings using "effectively" graded
index or refraction and scattering properties to improve light
transmission and light coupling to the skin. Other less flexible
coatings or polymers could be used on top of the LED devices, so
flexing the LED strips would not be significantly impeded. This
would permit dyes to be used directly on the LEDs in these films
(such as acrylic) either above or in a silicone coating.
[0149] An embodiment of the present invention incorporates pulsing
of the LEDs, if desired, as a way to modify the therapy or to
reduce the average power to the LEDs and thereby reduce the nominal
intensity without changing voltages. The LEDs can be modulated or
switched on and off at 4-over 100 million cycles a second depending
on the drivers and type of LED, and/or at other frequencies and
duty cycles. 8-15 cycles per second is a preferred range for
neurological therapies, but modulation frequency is less important
for other therapies. Very high frequency modulation can be useful
for photoacoustic imaging, especially when coupled with
photoacoustic reporter materials such as high extinction red and
near-IR cyanine dyes, and may have other uses.
[0150] The discussion now provides several specific examples of
preferred embodiments of the present invention.
[0151] Referring now to specific Embodiment 1, there is provided a
light source, comprising an array of two or more LEDs and/or OLS,
where at least one of the LEDs and/or OLS has one or more materials
containing photoluminescent phosphor(s), dye(s), and/or OCSTs that
spectrum-shift most of the light energy emitted from the selected
LEDs and/or OLS into an emission spectrum substantially within the
ONIR wavelength range. Different spectrum-converting materials may
be mixed or sequentially placed in the light path so that 1, 2, or
more different spectrum converters are present in the light path of
at least half the collective initial LED light output.
[0152] Still referring to Embodiment 1, the spectrum converter can
be a phosphor or quantum dots mixed into clear silicone or other
matrix material placed in the proximity of, or touching the LED
light-output surface at a concentration, thickness, and area that
can convert 50% or more of initial LED light into broad spectrum
ONIR light with a emission intensity dominant peak at 620 nm or
higher. In the example provided, we use a broad emission spectrum
commercial phosphor .about.650 nm peak emission nitride or
oxynitride red phosphor with an internal QY above 70% such as can
be commercially obtained. BASF 305 red dye provide absorption in
the blue-green-yellow spectral ranges with a peak emission near 610
nm and an emission tail past 750 nm. We have also found that an
even deeper red shifted spectrum can be obtained using a 0.01%-0.3%
concentration of a special new 670 nm peak emission Perylene dye
placed over the red phosphor coated LED above. An additional
phosphor in this range is LED NR655, which is a 655 nm emission
peak nitride phosphor from SHANGHAI RURAL INDUSTRIES CO., LTD. In
China.
[0153] The amount of blue or violet light left unconverted depends
on the exact design parameters used and needs to be experimentally
established for each device and phosphor matrix parameters used. A
second phosphor such as Intermatix 670 nm phosphor, single or
multiple near-IR emitting quantum dots from QD Vision Corporation
or Nano Optical Materials (there are also other sources), or
near-IR emitting phosphors from Taylorlux or Materion can be mixed
into Material 1 or added as a second material in the light path to
further extend the light emission over the spectral range over the
Near IR range. The spectrum of this embodiment can also be
supplemented with one or more unconverted LEDs with peak emission
in the upper near IR range such as 780 nm, 810 nm and/or 840 nm
LEDs. Because of low cost manufacturing tolerances and a wide
useful biological response in the range, this is effectively a
preferred 770 nm-860 nm range of dominant spectral peaks.
[0154] The light source device described for Embodiment 1 is unique
because of the specific "broad spectrum" ONIR light spectrum
created by the synergistic interactions of the LEDs and/or OLS and
the special broad spectrum converters. The light emission spectrum
has the important unique capability of providing light energy
covering all or almost all of the ONIR spectral range that can
provide therapeutic light energy benefits to shallow through to
deep tissues, but also providing light intensity peaks to address
specific important therapy or biological process. This is done in
more cost effective way than previously disclosed. The use of
efficient solid state Light Emitting Diodes or laser diodes is the
preferred embodiment of this invention.
[0155] A specific example, designated as Embodiment 2, has an
additional light conversion material placed in all or part of the
light path, consisting of one or more over 60% quantum yield dyes
in an inorganic or polymer matrix such as polycarbonate, impact
resistant acrylic, or PVC. Polymer matrix mixtures are anticipated
and can be beneficial. For most preferred embodiments 0.05-5 mm
would an optimal range.
[0156] Selected perylene derivative dyes have much higher
photostability, higher QY, and ease of integration into a wide
range of light converters than almost any other red or near-IR
spectral range organic dyes. Even though photostability is lower
than phosphors, this can be managed in many medical applications
for the life of many products or the conversion material can be
changed out as part of routine maintenance. The absorption and
emission characteristics are needed for useful ONIR spectrum.
[0157] The present invention incorporates inclusion of two new
perylene derivative photoluminescent dyes which provide broad
spectrum light emission with emission peaks at .about.775 nm and/or
.about.820 nm. These emitting dyes are important examples of new
near-IR dye with broad band peak emission at about 775 nm and 820
nm respectively. This new 775 nm emitting dye is used as the
spectrum converter in Embodiment 2 in which light absorption in the
violet and in the 595-720 nm range uniquely allows single-step
conversion to a broad near-IR spectrum center around 775 nm from
violet, and then double conversion from red light. If this dyed
material is only placed in the light path of unconverted violet
LEDs, or over orange-red emitting LEDs (630 nm), the overall light
source efficiency can be further improved and tailored. Additional
combinations and variances of these basic structures are
anticipated. One or more types of QDs with emission peaks in the
760 nm-860 nm spectral range can be substituted.
[0158] Still referring to the Embodiment 2 example, a specific
example of the added spectrum converter material would be a
.about.0.2 mm thick flexible and transparent polycarbonate sheet or
other suitable polymer with 0.1% 775 nm dye for the subsequent
spectrum converter. Similar concentrations of QDs may also be
used.
[0159] Still referring to Embodiment 2, the subsequent spectrum
converter can alternatively contain both the 780 nm and 820 nm
derivative dyes, phosphors, and one or more type QDs with emission
peaks in the 760 nm-860 nm spectral range. A concentration ratio of
0.08% 775 nm dye and 0.06% 820 nm dye can be used to greatly
increase light output over the 740-860 nm range. A 2% addition of
poly vinyl chloride (PVC) to the polycarbonate during the converter
sheet fabrication can improve the quantum yield for this dye and/or
the 820 nm dye.
[0160] Still referring to Embodiment 2, the subsequent spectrum
converter may also contain one or both of these new
perylene-derivative dyes, the older fluorescent perylene dyes,
and/or one of more other spectrum converters such as phosphors.
[0161] It should be noted that the afore-mentioned embodiment, and
its variations, is very unique as it uses selective light
absorption and dual light emission to optimize ONIR light output.
These spectrum converters are not just mixtures or combinations.
Rather, these are highly interactive, synergistic materials that
work together uniquely. The absorption and emission curves plus
non-photon energy transfers provide higher performance and energy
efficiency than one knowledgeable in the arts would have
anticipated.
[0162] An Embodiment 3 of the spectrum converter is comprised of a
light source consisting of an array of two or more LEDs with
principal light output in the 390-490 nm range, where at least one
of these LEDs is covered by one or more layers closest to the LED
containing photoluminescent phosphor(s) and/or quantum dots so that
over 50% of the output light spectrum from the converted LED(s) is
within the ONIR spectral range. Additional spectrum-converting
layer(s) using fluorescent dye(s) or quantum dots then converts
most of the of the light energy exiting the first layer(s) into the
ONIR spectral range, and/or into a longer wavelength portion of the
ONIR spectral range. This device's output light from the spectrum
converter(s) may intentionally contain up to 40% light in the
violet and/or blue spectral range with >60% light in the ONIR
spectral range. Light source designs with over 99% of the photons
in the ONIR range are achievable with this structure and
appropriate photoluminescent material concentrations and layer
thicknesses.
[0163] Embodiment 4 of the spectrum converter: According to another
aspect of the present invention, there is provided a light source,
comprising an array of two or more light-emitting diodes, where at
least one of the LEDs is covered by one or more layers containing
fluorescent dye(s), phosphorescent dyes, photonic crystal-like
arrays, and/or quantum dots to color-shift yellow, orange, or red
(580-650 nm) light energy from LED(s) into the ONIR wavelength
range and/or into longer wavelengths within the ONIR spectral
range.
[0164] In any of the above-described embodiments of this invention,
additional LEDs (whether spectrum-converted or not
spectrum-converted), may be added to the apparatus to increase the
light intensity in certain portions of the light spectrum. For
example, if the light output from the spectrum-converters and LEDs
has a dominant peak light intensity at 650 nm, then the light
output at 800 nm may be lower than desired for some LLLT
applications, even though example phosphor and fluorescent
converters with 650 nm peak emission intensity will provide some
photons 150 nm above the peak output. Additional LEDs can be added
to increase intensity in the longer wavelength portion of the
spectrum. For example, 665 nm, 680 nm, 720 nm, 735 nm, 760 nm, 780
nm, 810 nm, 820 nm, 840 nm, 850 nm, and/or even up to 940 nm
dominant peak range LEDs may be added to the light source. Longer
wavelength peak emission color converter layers can also be used on
some or all LEDs to shift the average spectrum from shorter to
longer wavelengths via a spectrum-conversion cascade. Violet or
blue LEDs could also be added without color converters to create
spectral peak(s) in the short wavelength range.
[0165] In these embodiments, spectrum-conversion may be
accomplished either by having the incident light pass though the
translucent spectrum-converting medium for one of more of the
layers placed (1) between the light source and the surface to be
illuminated as sheets or coatings, (2) the translucent film(s)
containing the photoluminescent materials on or over flat or shaped
reflective surfaces, (3) the photoluminescent materials may be
imbedded in fiber optics (e.g., polymer with low index of
refraction coating), and/or (4) as optical structures such as
prisms, lenses, or lens arrays.
[0166] As a further specific example of the invention's previously
described Embodiment 1, a simple 1 layer converter design includes
a VIB LED (e.g., 430 nm or 450 nm dominant peak) beneath a 0.3 mm
thick mat-finish impact resistant acrylic film containing a mixture
of 610 nm and 670 nm perylene dyes (0.2% concentration for each
component dye, total 0.4% concentration). BASF red 305 perylene dye
also provides for a reasonable example dye for this embodiment.
[0167] This type combination of dyes in this concentration range
can absorb and convert enough of the 430 nm light to provide an
output light spectrum with over 70% ONIR light with a 670 nm peak
light, and retain a VIB light peak LEDs. The 610 nm dye absorbs
much of the VIB light and efficiently transfers much of its energy
to the 670 nm dye. This example device using the 430 nm LEDs would
be useful for many skin therapies and deep tissue therapies, but
also would be useful for plant growth and blooming or ripening if
powered by 450 nm LEDs. This example can be made using two 0.22 mm
thick layers of dyed film with the 610 nm dye closest to the LED
and then the 670 nm dye may be optionally placed over the 610 nm
dyed film. Alternate polymer films such as polycarbonate or PVC may
be used and other spectrum converter dyes or phosphor may be
inserted as extra layers or mixed in the film.
[0168] A further example of the invention's Embodiment 2 uses a 650
nm-peak emitting phosphor suspension in a silicone polymer coating
placed over LEDs with a significant amount of its light emission
within the 400-435 nm spectral range. The concentration of the 650
nm phosphor in the silicone is approximately .about.11-20% (weight
%) in the 0.1-0.2 mm thickness range. This spectrum-converter on
this type violet-blue LED can provide light with over 70% of the
light within the ONIR spectrum. Optionally, then a 670 nm dominant
peak-emitting perylene dye at .about.0.25% concentration (weight %)
in a .about.0.2 mm thick, textured (e.g., mat-finish or other light
scattering surface) acrylic, PVC, or polycarbonate film is placed
over the 650 nm-phosphor converted LED. The combination of these 2
spectrum conversions can provide light emission spectrum centered
in the 645-675 nm spectral range with less-than 15% of the peak
emission intensity for wavelengths under 610 nm. An alternative is
to mix 650 nm phosphor and 670 nm phosphors together or to use 650
nm phosphor with 670-700 nm QDs. 1-15% of the photons in the output
spectrum can remain in the violet range if anti-microbial
functionality is desired. Alternatively if using much higher
collective phosphor, dye, and/or QD concentration, almost no violet
or blue light may be left in the spectrum depending on the
application using thicker or higher concentration phosphor and/or
dye in either or both of the polymer film layers. Additional layers
of spectrum converting films with longer peak emission wavelength
dyes or quantum dots may be used to further shift all or part of
the output light spectrum to longer wavelengths.
[0169] "Low-temperature melting Glass" (LT Glass) can be used as a
matrix for certain perylene derivative dyes if the glass transition
temperature is below 450.degree. C. For phosphors in glass, the
glass transition temperature can be much higher and can include
many types of glasses, depending on the phosphor used; however
index of refraction matching between the glass and phosphor grains
becomes more important.
[0170] LT Glass matrix: Several perylene fluorescent dyes and/or
phosphor and dye mixtures can be inserted into a
low-softening-temperature glass to provide spectrum converters.
Example sources of translucent low-temperature glass (powder or
solid): Low-melting Glass Powder (TF-100H, TF-100HF) from Taizhou
Sunflex Industrial Co., Ltd. In China, Satake Glass Company in
Japan (leaded or non-lead glass), and ARTCO Inc. in the USA). It is
non-obvious that organic fluorescent dyes can be mixed into glass
and be made highly active. This is unique to this perylene class of
organic dye. Phosphors mixed in glass are known, but the use of
high-temperature capable organic fluorescent dyes into glass is
new. The unique class of perylene high stability, high temperature
derivatives dye can be mixed into a glass powder before melting, or
into molten glass. A low oxygen and moisture environment is
preferred during mixing and melting (e.g., nitrogen, argon, and/or
vacuum). Mixing can be accomplished using agitation (vibration,
ultrasonic, shaking, spinning, pumping, and/or stirring). The mix
can be prepared at above the LT Glass melting point (prefer 450-550
deg. C. for under 1 hour). The molten glass can then be placed
directly over LEDs, and/or molded into shapes, placed in droplet
arrays on surfaces, or otherwise formed to make flat or curved
filters, lenses (including microlens arrays), and other shapes.
Glass droplets or other molded glass shapes may be placed onto
other transparent or reflective materials or other structures to
diffuse or focus light. Dye concentrations between 0.01 and 5% are
considered useful depending on the application. 0.15-0.35% (weight
%) is an example optimal range for some converter medical
applications using the 670 nm emission peak perylene dye for blue
to red-orange light sources. 0.1-30% phosphor (weight %) may be
added to the dye is starting with UV, violet, or blue light
sources. These spectrum converter materials may be designed into
multiple layers or mixed into the glass. Films or coatings (polymer
or other translucent materials) of dyed, phosphor, or other color
converter layers may be added as layers.
[0171] Additional dye options include Rubrenes, rhodamines,
cyanines, and many europium complex dye derivatives which have
usable characteristics for these new device structures in
translucent polymer material matrices, although these dyes are
inferior in photostability and quantum yield to the referenced
perylene dyes.
[0172] Orange-red LEDs with primary dominant peak light emission in
the 610-630 nm range can be efficiently converted to provide light
with dominant peak emission in the 660-680 nm range and with over
70% of the output light spectrum for most published ONIR skin
treatments that do not require UV or VIB spectral range light. The
NIR tail above 680 nm provides improved depth of tissue penetration
by NIR light. In this example, a .about.670 nm perylene derivative
fluorescent dye in a suitable translucent medium is used (e.g.,
0.15-0.35% dye in 0.10-0.35 mm thick polycarbonate (PC), polyester
(PE), acrylic, polyvinyl chloride (PVC), and/or other translucent
medium such as LT glass). Alternatively, 640-700 nm phosphor or QDs
may be used over the UV, violet and/or blue LEDs. These orange-red
light converters and the prior violet-blue light conversion devices
may be mixed together in the light source and/or combined with
other LED types to create lower cost, high energy efficiency, and
improved LLLT and PDT activating light sources. Also, the >20%
of the output photons in the >700 nm range are known to enhance
plant ripening and/or blooming while the remaining broad-red
spectrum light provides the energy for accelerated plant growth. A
small amount of added violet and blue light can also provide for a
versatile horticultural lamp. The violet-blue spectral range light
can be provided by mixing Example 1 and Example 2 device types,
and/or by adding supplemental VIB LEDs to either light source.
[0173] In another even more specific example embodiment of this
invention, violet LEDs with a significant (>10%) amount of the
LEDs' light output being in the 400 nm-465 nm spectral range are
used to drive the above color converters to provide a unique light
spectrum for skin treatments with both antibacterial and healing
properties. The output spectrum (photon ratio as %) for this
embodiment of the invention is >65% ONIR light and 2-35% violet
light in the 400-435 nm range. This output light spectrum can be
obtained without the use of mixed LED types. Some high value uses
are for acne treatments, skin care and rejuvenation, wound healing,
and PDT using mixed short and long wavelength photosensitizers.
[0174] In embodiments of the present invention, multiple dyes
and/or phosphors or quantum dots may be mixed or layered to provide
many different ONIR range spectra that can be optimized for
specific uses. For example; an intensity-vs-wavelength spectrum
light can be generated efficiently from UV, violet, blue, and/or
orange LEDs over ONIR ranges such as with less than 30% variation
from the peak emission intensity covering the 620-690 nm range
using the example materials discussed. A significant amount of
light can be generated by the "tail" of the example dye and
phosphor emission spectrum providing up to 5% of the peak light
emission out to almost 800 nm.
[0175] Another specific variation of the embodiment uses a VIB LED
overlaid with a 0.1-0.2 mm thick translucent layer containing
mixture of .about.10-20%-620-630 nm dominant peak emission phosphor
and .about.10-15%-650 nm dominant peak emission phosphor, with a
second 0.2 mm thick translucent layer containing a .about.0.2%
concentration of .about.670 nm perylene dye or a 660-700 nm
phosphor or QDs can produce ONIR light with almost uniform
intensity over the 620-700 nm spectral range. These spectrum
converters may be driven by light sources in the 390-480 nm of
violet-to-blue light (VIB), phosphor-converted VIB light using
phosphors with emission peaks within the 595-700 nm spectral range,
or by 580-660 nm orange-to-red light (OR). Cascades of dyes may be
used.
[0176] The discussion now shifts to overall assembly of the
apparatus, but the spectrum converters described above provide some
of the most important core technology that has not been applied to
this area before. The arrangement of these LEDs and color
converters is important for an optimal wearable therapeutic and/or
diagnostic light source when a linear or area arrangement of the
LEDs is used. The area surrounding the LEDs should be substantially
light reflective in the spectral ranges to be output by the light
source (not necessarily specular or mirror-like), partial thermal
isolation (<0.5 W/mK overall forward heat transfer to tissue
surface) is provided between the target surface to be illuminated
and the LEDs, and one or more heat removal paths must be provided.
This invention describes multiple new heat removal paths are
provided that may be used independently or together.
[0177] The discussion now shifts to basically how and why we
assemble the LEDs and converters in a device. Specifically, the
LEDs used in this light source may be arranged linearly, over an
area, or at the perimeter of light guides, in addition to other
arrangements. A material in a grid-and-channel device structure is
placed between the tissue surface and the light devices that can
(1) remove heat from the illuminated tissue surface by conduction
and/or convection, (2) minimize heat transfer from the light
sources to the material to the tissue surface while allowing the
majority of the desired light spectrum to reach the tissue surface,
(3) reflect much of the reflected light and backscattered light
from the tissue back toward the tissue, and (4) remove heat from
the light sources (e.g., LEDs).
[0178] Overall structure Embodiment 1: In an example embodiment of
the overall structure of invention, LEDs and spectrum converter
structures, such as are provided for in Embodiments 1, 2, and/or 3,
are arranged on linear thermal-conducting strips or area arrays.
These LED strips or arrays are mounted onto a flexible high-thermal
conductivity base as a flexible heat sink using a
thermal-conducting adhesive, gel, or compliant material such as
soft thermal conduction silicone like is used for heat removal from
integrated circuit (IC) chips. The thermally conducting and
flexible backplane may include metal foil, wire grids, thermally
conducting silicone with or without imbedded fabric, foil, or wire
mesh. Additional heat conducting additives like ceramic, diamond
particles, or carbon fibers are optional.
[0179] Small rigid high power LED modules such as 6.times.1 cm or
8.times.1 cm strips may be placed together much like a tank tread
with the connecting wires for the modules. This can permit more
robust heat sinking to a thermal conducting material underneath
similar to using the fully flexible strips and can provide adequate
flexibility for many applications, especially when forming a
cylinder or partial cylinder to better bring light to some part of
the body from multiple angles.
[0180] For example, light therapy on a deep knee injury can be far
more effective if the light can be brought in from all 360 degrees.
Low light flux deep in tissue can be augmented by light from
multiple angles to provide an effective higher light dose deeper in
the tissue for a given incident radiant power and treatment
time.
[0181] In another preferred embodiment of this invention,
violet-blue LEDs are first over 50% converted to deep red using a
red-near IR phosphor (e.g., 650 nm peak phosphor), and then further
shifted into the deep red and near-infra red using a thin flexible
second polymer sheet (such as acrylic, PVC, polyurethane, or
polycarbonate) containing an organic fluorescent dye (e.g., 600-670
nm emission peak dye or over 650 nm emission peak QDs). The
phosphor and dye concentrations, and film thicknesses are adjusted
to absorb almost all the violet-blue (LEDs with a dominant peak
between 410 nm and 465 nm, preferably at 420 nm), but still pass
1%-15% of the blue-violet. This embodiment uniquely provides light
energy in the violet range (e.g. 5% of the light energy), a
dominant peak at 650 nm and 670 nm (50-50 mix) for shallow-medium
biological process activation, and a long dye+phosphor emission
spectrum tail past 800 nm for deeper penetrating biological process
activation. If supplemented with 780-830 nm and/or 840-850 nm
dominant peak LEDs, an effective spectral range of 595-880 nm can
be achieved (e.g., 595-780 nm, .about.800-820 nm, and
.about.835-850 nm or 760-790 nm, LEDs). However, one or more
spectral peaks in just the 760 nm-860 nm range may be considered
adequate for many applications. Shifting over 650 nm or 670 nm
light to longer wavelengths may be desired and can be accomplished
with appropriate color shifting materials such as by using a 700
nm-850 nm emitting dye and or one or more type 700 nm-850 QD the
same way as is disclosed herein.
[0182] The disclosed color-converted light source assembly is
placed onto a grid of high-translucence silicone cells and channels
to reduce conductive heat transfer through this translucent grid
and/or to provide peristaltic assisted and/or convection channels
for heat removal. Air channels are provided for in this example.
The peristaltic pumping of air action is powered by intentional or
unintentional pressure or movements of the users in this example,
but could also be powered by piezoelectric or other transducers
mounted along the channels. Pockets, bubbles, or pillars are
examples shown to further soften the surface of the light source
and to further reduce heat transfer to the tissue surface, channel
more light though hair, and/or to provide heat removal from the
tissue surface.
[0183] This invention provides a flexible heat sink for backside
heat removal in combination with a new integrated peristaltic air
and convection channel based heat removal system that uses heat
and/or body movements to increase air flow for heat removal from
the target (e.g., tissue surface) side of the light source.
[0184] Another novel aspect of this invention is unique integration
methods for heat-insulating air pockets to reduce heat transfer to
the skin from the LEDs.
[0185] One embodiment of this new conformable light source utilizes
a peristaltic air pump heat removal device structure powered by an
integrated channel system that utilizes body movements along with
convection, heat conduction, and radiation cooling. These
peristaltic chambers can pump or channel air, gas, or liquids into
and out of the light source to remove additional heat from the LEDs
and/or cool the skin using body movements, compression, and/or
other mechanical forces.
[0186] The ability to utilize these integrated passive and active
heat removal processes permits higher light intensities to be used
in a near tissue surface, conformal system with less heat related
discomfort.
[0187] This disclosed structure can also permit air flow around the
backside radiator and includes novel heat-conductive belt loops
that can act as part of the heat removal-radiator system. Also,
this invention discloses a novel use of a heat conductive flexible
strap that can act as part of the passive heat removal system if,
for example, the strap is made heat conductive using carbon fibers,
metal fibers and/or heat conductive materials such as
heat-conductive silicone. This strap can optimally be part of or
the same as the strap(s) that would hold the light source in place
on the body.
[0188] An optional opaque or partial-reflective perimeter cushion
may be included to reduce physical pressure on the treated area,
reduce tissue surface contact area, to provide an additional
potential cooling air flow path, and to reduce light leakage
laterally. Additional air flow across the tissue surface is
accomplished by open sections of this cushion or by providing
through-vents or pumped area though the cushion.
[0189] In one embodiment, the LEDs are mounted using a thermally
conductive adhesive or by compression onto a flexible and/or
segmented heat sink such as thermal silicone sheet material, carbon
and/or metal fiber flexible composite materials, graphite strips,
or metal foil with over 0.5 W/mK vertical and horizontal thermal
conductivity. This heat sink provides a heat transfer pathway to
the ambient temperature air on the backside of the heat sink. The
backside of the heat sink may be cooled by ambient air heat
transfer from its surface. The backside surface of the heat sink
may have an increased surface area for improving heat-to-air
transfer or an attached high surface area heat exchanger.
[0190] The heat sink system may include a flexible heat conductive
strap material behind and in partial or full contact with the
backside heat sink material to further increase heat dissipation
(e.g., a thermal conductive silicone or other heat conductor with
fabric inlay or backing for strength.
[0191] Optionally, the area in front of the LEDs and/or behind the
backside heat sink can be actively-cooled using a pumped liquid
coolant, a peltic cooler, or forced air cooling using a blower or
fan.
[0192] In another embodiment of this light source, pumped air or
pumped coolant (e.g., water) through these channels is used to
further reduce the tissue surface temperature and to permit higher
light intensities to be used.
[0193] In another embodiment of this light source, air or liquid
coolant flowing through transparent channels or bladders (through
one or more channels) between the targeted surface and the light
source are used to remove even more heat from the tissue surface,
allowing much higher intensity light to reasonably thermal
conductivity material such as transparent silicone and no thicker
than necessary for structural stability. This method can remove
heat directly from the tissue surface, including removal of some
heat generated by the absorption of the therapeutic spectrum itself
by the tissue surface. This added active cooling can be combined
with the active cooling using internal air or liquid coolant
channels. Alternately, fans or blowers with air channels consisting
of rib-cage like heat sinks may be utilized to remove heat from the
device and still permit flexibility.
[0194] According to another aspect of the present invention, there
is provided a light source for therapy and/or diagnosis, comprising
one or more flexible light pipes, light channels, or large area
light panel (s) with perimeter mounted LEDs, or with LEDs
conforming with the shape of an external area to be treated or
exposed to light.
[0195] These same light channels, or additional light channels, can
also be used to collect and deliver light reflected from or emitted
from the target (e.g. skin or tissue) to sensors in the light
source device. These sensors may be spectrometers, thermal IR
sensors, or simple photocells with optical filters to assess the
spectrum reflected or emitted from the target. The reflected
spectrum can be used to assess the skin reflection and absorption
for target surface heat and light dosimetry, or for assessing the
presence and concentration of fluorescent or phosphorescent
compounds such as photosensitizers, biological materials, or other
materials. The light pipes or light panels may be provided with a
structure on either the front or back surface as indentations,
bumps, or columns to improve uniformly of light distribution or to
reduce heat transfer through the material. Forced air or liquid
heat removal is also anticipated from the surface of the device,
perimeter, or one or more internal heat removal channels.
[0196] According to another embodiment, a method of selective
photodynamic therapy comprises: introducing the selective
photoluminescent compound to a body having a target cell, wherein
the selective photoluminescent compound is configured to
selectively attach to or enter the target cell; introducing an
activating light to the selective photoluminescent compound,
wherein the photoluminescent compound is configured to absorb the
activating light and emit an emission light having a different
wavelength than the activating light; and activating a
photocytotoxic compound with the emission light of the selective
photoluminescent compound.
[0197] According to yet another embodiment, a light source
comprises: a light pathway including converted spectra configured
to transmit a light of a first wavelength; and a tip section having
a photoluminescent material located along the light pathway, the
light of the first wavelength configured to be received by the
photoluminescent material of the tip section and emitted from the
light source as an emitted light having a second wavelength.
[0198] Photoluminescent dyes, phosphors, and quantum dots can be
mixed and suspended in a variety of polymers or other translucent
medium materials such as silicones, silicates, sol gels, polymers
and can be painted on surfaces or shaped into structures such as
lenses or in sheets.
[0199] The present invention may be incorporated into a device
which is either stationary or portable and/or wearable. The light
source may be incorporated into materials which are rigid such as
plastics, composites, or metal housings, or into flexible materials
such as silicone. This invention may also be built into a variety
of fabric designs.
[0200] The discussion now shifts to additional specific embodiments
of various structures and features of the present invention and its
components.
[0201] The present invention provides for an array of
light-emitting diodes (LEDs) as a light source for therapy and/or
diagnostics or other applications, comprising an array of 2 or more
light-emitting diodes with at least one of the LEDs overlaid with
spectrum-converting fluorescent and/or phosphorescent containing
materials, or photonic spectrum-shifting structures such that at
least 30% of the light energy from the LEDs passes through the
spectrum-conversion layer(s) and is absorbed by these layers. After
the spectrum-converters, over 50% of the modified photon flux must
contain light in 595-860 nm spectral range. LEDs without
spectrum-converters in the array, if any, must contain at least one
LED of either dominant peak wavelengths within the 400 nm to 495 nm
spectral range, and/or dominant peak wavelengths within the 580 nm
to 950 nm spectral range.
[0202] An embodiment of the present invention provides for LEDs
that are arranged on a flexible heat-sinking backplane with over
0.5 W/mK thermal conductivity, and with one or more soft
translucent window layers above the LEDs. The
to-be-spectrum-converted LEDs in the array have emission spectra
substantially in the range 360 to 640 nm range before the spectral
converters. The dominant peak emission of the
to-be-spectrum-converted LED(s) is in the 400 nm to 450 nm range,
the spectrum-conversion material over the to-be-converted-LEDs is a
phosphor and/or fluorescent or phosphorescent dye and/or quantum
dot containing layer, and/or photonic crystal lattice with the
majority of the layer's light absorption spectrum in the under 460
nm range, and over 70% of the light emission of the dye or phosphor
is within the 595-860 nm spectral range.
[0203] An embodiment of the present invention provides for a light
source where the spectrum conversion material is a phosphor,
fluorescent or phosphorescent dye, and/or quantum dots with
substantial light absorption in the under 480 nm spectral range,
and/or a fluorescent dye, QD, or photonic crystal structure with
the majority of its absorption spectrum in the under 650 nm
spectral range, and where over 70% of the light emission from the
color-conversion layer(s) is within the 595 nm to 860 nm spectral
range.
[0204] An embodiment of the present invention provides for a light
source where up to 15% of the non-converted photon flux from the
before-spectral-conversion-LEDs is in the 350 nm-465 nm spectral
range for antibacterial, possible macrophage activation, possible
collagen restructure initiation, blue-to-violet wavelength
photosensitive chemical activation based treatments coupled with
red to near-infrared spectral range based treatments.
[0205] An embodiment of the present invention provides for a light
source where additional LEDs without spectrum converters may be
also used to add light energy to parts of the spectrum between 350
nm and 450 nm, or between 595 nm and 950 nm.
[0206] An embodiment of the present invention provides for a
phosphor layer where the phosphor(s) are in the 1%-40%
concentration range within a highly-translucent matrix or sol gel,
silicate, silicone, or organic polymer and exhibits an internal
quantum efficiency over 60%, and/or where a fluorescent dye or
quantum dot based spectrum-converter(s) is dissolved in the
0.05%-10% concentration in an organic polymer or other
highly-translucent material placed between the LEDs and the target
to be illuminated. (The thickness and concentrations of the
spectrum converting films are adjusted to provide the desired
spectral characteristics for a specific treatment.)
[0207] An embodiment of the present invention provides for a light
source where the area immediately surrounding the LEDs or
surrounding the LED's flexible printed circuit board strips is at
least 40% reflective to, or non-absorbing of light in the 595 nm to
860 nm spectral range.
[0208] An embodiment of the present invention provides for a light
source where the area in front of the LEDs is one or more
translucent windows providing low thermal conduction in the
direction of the under 860 nm light. A grid of air or gas pockets
and/or air channels is claimed with at least one solid zone of
highly translucent material placed between the target to be
illuminated and the LEDs.
[0209] An embodiment of the present invention provides for a
backside's heatsink structure that permits air flow around the
backside radiator and includes belt loops that act as part of the
heat removal system, minimizing the effect of elastic straps.
[0210] An embodiment of the present invention provides for a light
source where the area in front of the LEDs is one or more
translucent windows providing low thermal conduction in the
direction of the under 960 nm light. A grid of liquid, air, or gas
pockets with channels that can allow peristaltic air pumping when
the LED light source is bent and/or moved to increase convection
flow to assist in the removal of heat from the front side of the
LED array.
[0211] An embodiment of the present invention provides for a light
source according to Claim 13, where the channels contain pumped air
or liquid coolant.
[0212] An embodiment of the present invention provides for a light
source where the area in front of the LEDs is one or more
translucent windows providing low thermal conduction in the
direction of the under 960 nm light. In such embodiment, grid
vertical wall structures (e.g., bowl, box, or honeycomb-like)
facing the target-to-be-illuminated surface provides reduced
conductive heat transmission because of additional air gaps and/or
provide a small reservoir for skin or tissue surface lotions, gels,
or liquids.
[0213] An embodiment of the present invention provides for a light
source where the area in front of the LEDs is one or more highly
translucent windows providing active heat removal. Air or liquid
coolant channels are claimed with at least one solid sheet of
highly translucent material between the target to be illuminated
and the LEDs.
[0214] An embodiment of the present invention provides for a light
source where a flexible layer is placed in front of the LEDs that
is one or more translucent windows that is also partly-reflective
or partly-blocking to infrared (IR) light, such as IR absorbing
films, dichroic filters, or using other types of interference
filters or photonic lattice arrays.
[0215] An embodiment of the present invention provides for a light
source where the area surrounding most of the perimeter of
translucent window(s) over the LEDs is a raised mostly-opaque
structure to act as a soft cushion if placed against the tissue
surface and to reduce lateral light. The cushion structure or
material may be a soft-solid, tubular, bladder, or partly coiled
structure. The cushion structure can be reflective,
partly-reflective, or mostly opaque to light primarily in the
400-460 nm and 595-860 nm spectral range.
[0216] An embodiment of the present invention provides for a light
source where one or more light sensors are placed in or near the
LED array, facing toward the target of the illumination, that
detect reflected light from the target. These sensor(s) are to be
provided with a circuit to adjust the light intensity based on
tissue surface reflectivity at the wavelength ranges being used.
Multiple sensors sensitive to different wavelength ranges are
claimed for the detection of preferential reflected wavelengths of
light and to permit manual or automatic adjustment of relative
power to the mixture of different color LEDs.
[0217] An embodiment of the present invention provides for a light
source where one or more Infrared light sensors are placed in or
near the LED array, facing toward the target of the illumination
that detect heat at the target. These sensor(s) are to be provided
with a circuit to adjust the light intensity based on tissue
surface temperature.
[0218] An embodiment of the present invention provides for a light
source where the infrared sensor self-calibrates to the tissue
surface temperature prior to activation of the LED light sources,
allowing control based on a change in tissue surface temperature
and/or actual tissue surface temperature. This system would provide
an automatic feedback warning or shut off at predetermined
levels.
[0219] An embodiment of the present invention provides for a light
source where the temperature or other sensors are placed on or in
the patient's tissue to measure surface temperature before, during,
and/or after the treatment. Temperature monitoring may be in the
light treatment zone or elsewhere. Feedback from these sensors are
for allowing control based on a change in tissue surface
temperature and/or actual tissue surface temperature, or other
parameters based on the type of sensor and data gathered. This
system could provide an automatic feedback warning or shut off at
predetermined levels.
[0220] An embodiment of the present invention provides for a light
source where the controller can call an attendant to a patient a
designated amount of time before the treatment time has ended or
when the treatment has completed, when the patient turns off the
system or presses a call button, a system failure occurs, and any
of several other conditions or situations.
[0221] An embodiment of the present invention provides for a light
source where one or more temperature sensors are placed in the LED
array and/or near surface of the, facing toward the target of the
illumination, that can be used to control temperature by adjusting
the LED intensity, or for providing a warning or automatic shut off
power if the temperature of the array or transparent pad surface
exceeds an approximate predetermined value.
[0222] An embodiment of the present invention provides for a light
source where vibrating (6-2000 Hz) and/or ultrasonic transducers
(Over 20,000 Hz and under 110 MHz) are placed in the proximity of
the LED array to enhance the effectiveness of the light sources
alone, or when used with liquid or cream tissue surface treatments,
cosmetics, or photosensitizers by opening pores, increasing the
transport of compounds through cell membranes, and potentially
increasing blood or lymph fluid flow.
[0223] An embodiment of the present invention provides for a light
source where the translucent light emitting portion of the source
is a pad between at least 1 cm wide by 1 cm long, and up to 0.5
meters in length and up to 0.3 meters wide that can placed around
the afflicted area of the body, or placed over, under, or beside
the target to be illuminated.
[0224] An embodiment of the present invention provides for a light
source where the light source is a long light emitting pad between
0.5 meters long and 50 meters long of any practical width that can
be coiled around the afflicted area(s) of the body, or otherwise
placed around, over, under, or beside the target to be
illuminated.
[0225] An embodiment of the present invention provides for a light
source where the light source is a partial or full body system with
the light source providing light therapy from 2 or more sides
simultaneously. An embodiment of the present invention provides for
a light source where the light source is a light emitting pad used
for wound healing and other tissue surface, tissue, or inflammation
treatments with a very soft jelly like silicone or similar
transparent surface against the tissue surface. A perimeter ridge
can be placed to further hold in any creams of liquids against the
tissue surface.
[0226] An embodiment of the present invention provides for a light
source where surface of the soft material, as described above, is
indented with dimples or formed into bumps, formed into an
egg-crate grid, or formed into a large number of finger-like or
other cross-section shaped protrusions to further soften the
surface and hold photosensitizers, emoluments, antimicrobial or
antibiotic materials, and/or other creams, gels, or liquids for
long term contact with the tissue surface. A perimeter ridge is
optionally placed to further hold in any creams, gels, or liquids
against the tissue surface.
[0227] An embodiment of the present invention provides for the
surface of the soft material against the tissue surface, as
described above, to consist of an array of translucent columns,
bumps, or other extensions to improve light transmission through
hair and reduce tissue surface heating.
[0228] An embodiment of the present invention provides for a strap
mechanism to hold the treatment system in place on the patient. The
strap can be a belt going through belt loops on the light therapy
system with any number of fastening methods. Said belt may be made
thermally conducting to further assist in heat removal from the
back the system.
[0229] An embodiment of the present invention provides for a strap
mechanism to hold the treatment system in place on the patient. The
strap can be connected to the device by Velcro, buttons, snaps,
zippers, clamps, adhesives, gels, suction, or any other adequate
system that can hold the light therapy system in place.
[0230] An embodiment of the present invention provides for a
mechanism to hold area light therapy system modules on or near the
patient. The mechanism may be a mechanical system holding 2 or more
LED arrays in specific positions and distance from the patient
treatment system in place on the patient or a system that can be
shaped to large portions of the patient body. The mechanisms
holding the light therapy system may be frames, adjustable
brackets, or of the building tanning bed or booth like, mobile or
primarily stationary.
[0231] Patients may use disposable or reusable transparent
materials over their skin to minimize contamination of the light
therapy system or the patient. Examples would be clear plastic or
silicone arm or leg covers, or other type of partial or full body
covers.
[0232] An embodiment of the present invention provides for a light
source that positions the LED toward bundles of multiple fiber
optic loops or coils to concentrate the light in a forward
direction or other designed direction.
[0233] An embodiment of the present invention provides for a light
source that positions the LEDs toward bundles of fiber optic loops
or coils to concentrate the light in a forward direction and uses
phosphor, quantum dot, fluorescent or phosphorescent dye doped
fibers, and/or photonic crystal fibers to provide all or part of
the LED's spectrum conversion, including the optional creation of
coherent fiber laser light sources.
[0234] An embodiment of the present invention provides for a method
using a light source that places a large area light source (area
over 50 cm2) in area on the head, and/or neck, using straps or head
gear for increasing the generation of nerve stem cells in the
brain, or spine, traumatic brain injury treatments, pain reduction,
and for mood treatments.
[0235] An embodiment of the present invention provides for a method
using a light source that places a large area light source (area
over 50 cm2) on the body for improving internal organ function or
accelerating tissue repair.
[0236] An embodiment of the present invention provides for a method
using a light source, that places a light source over wounds for
improving healing and tissue surfaces, dermatology treatments, pain
reduction, and/or tissue regeneration.
[0237] An embodiment of the present invention provides for a method
using a light source that places a large area light source (area
over 50 cm2) on the body for enhancing muscle growth during or
after exercise.
[0238] An embodiment of the present invention provides for a method
using a light source that places a large area light source (area
over 50 cm.sup.2) on the body such as joints and muscles for
improving tissue regeneration, pain reduction, and inflammation
reduction.
[0239] An embodiment of the present invention provides for a method
using a light source that places a large area light source (area
over 50 cm.sup.2) for veterinary use for tissue regeneration, pain
reduction, and inflammation reduction.
[0240] An embodiment of the present invention provides for a light
source where the light source is used to provide energy for
botanical plant or algae growth.
[0241] An embodiment of the present invention provides for a light
source where the light source is used for purification and
antimicrobial treating of water or body fluids, with or without an
added photosensitizer.
[0242] An embodiment of the present invention provides for a light
source where the light spectrum converter without the heat sink or
translucent heat barrier opposite the light source that is used for
enhanced botanical plant or algae growth, or for purification and
antimicrobial treating of water or body fluids, with or without an
added photosensitizer.
[0243] An embodiment of the present invention provides for a light
source including 2 or more over 5 gauss magnets, with said magnets
preferentially arranged in an alternating North-South patterns, and
mechanically moved or reversed as required. Electromagnets may also
be optionally not used, used continuously, pulsed, or reversed.
[0244] An embodiment of the present invention provides for a light
including with 1 or more piezoelectric, capacitive, inductive, or
magnetostrictive transducers, or motors to generate ultrasonic
energy and/or vibration from the light source in continuous and/or
pulsed energy.
[0245] An embodiment of the present invention provides for a light
source including electrodes to provide pulsed AC current to
stimulate tissue surface and tissue locally under and/or near the
light source.
[0246] An embodiment of the present invention provides for a
combination of all or any subset of the integrated technologies
provided above.
[0247] An embodiment of the present invention provides for
utilization of the light source(s), and/or certain components
thereof described herein, for various applications not specifically
listed herein, including but not limited to the fields of medicine,
veterinary, biomass growth and control, horticulture, cosmetics,
photodynamic therapy (PDT), low level light therapy (LLLT), light
influenced biological processes, diagnostics, lighting for
photo-luminescent based imaging, and/or other medical or
non-medical applications.
[0248] The present invention, or embodiments thereof which may use
all or parts of the described spectral ranges, is applicable to
light therapy devices and methodologies including but not limited
to (1) Low level light therapy (LLLT) for the treatment of
inflammation and/or for tissue surface, other tissue healing, skin
and tissue rejuvenation, muscle growth enhancement, muscle repair
and pain reduction, accelerated tendon healing, joint or cartilage
treatments, plantar fasciitis, pain management, traumatic brain
injury (TBI) damage risk reduction, neurologic rejuvenation,
enhancing stem cell generation, enhancing mood, and/or enhanced
rate healing of wounds, blood and body fluid treatments (with or
without photosensitizers), spider vein and/or varicose vein and/or
scar and/or stretch mark reduction treatments with or without
photosensitizers, reducing arterial plaques or other undesired
biological materials using photosensitizers, treating biofilms on
natural and/or man-made surfaces in or on the body, carpal tunnel,
fibromyalgia, tendonitis, bursitis, tendonitis, migraines, carpel
tunnel, osteoarthritis, dental root and implant healing or bone
regrowth, for enhancing the rate for other bone healing,
accelerating T-cell life cycles and activity, accelerating
macrophage action, veterinary applications, and/or providing many
other health related medical benefits, (2) activation of
photosensitizers used in Photodynamic therapy (PDT) for cancer or
antimicrobial treatments using natural or synthetic
photosensitizers, including photosensitizers produced by bacteria
in or on the body, (3) imaging and diagnostics using the emitted
light spectral range, (4) Intense Pulsed Light (IPL) therapies,
sidereal or other mood therapies, (5) activation of adhesives or
scaffolding agents as a part of reconstructive or cosmetic surgery,
(6) photoactivation of release agents to separate structures of
compounds for surfaces, (7) powering of photocell driven devices in
the body, and/or (8) other uses such as light-sensitive chemical
activation, and/or use of this light therapy in combination with
ultrasonic, vibration, thermal heating or cooling, and other
combinational therapies.
[0249] cooling system for a flexible LED array consisting of:
Multiple LEDs mounted on a flexible PCB with openings or
heat-conductive material under and/or around each LED to provide a
pathway for heat to underlying heat sinks using, braising, solders,
or eutectic bonding, conductive composite materials, low melting
point metal alloys, thermally conductive grease, and/or thermally
conductive adhesive materials.
[0250] A heatsink consisting of a thermally conducting material
such as graphite, metal such as aluminum, plated or laminated
metals, thermally conductive composites such as thermal conductive
silicone or flexible carbon fiber, diamond particles, or metal
fiber composites. These structures can be arrays of multiple rigid
plates to effectively create a flexible tiled structure that are
held together or may be flexible structures. Multiple layers of
these materials may be used.
[0251] A cooling system consisting of a flexible molded or assembly
of sheet material such as silicone or other polymers on the
backside opposite the LEDs. This structure will have one of more
electrical conductors in or on the polymer structured to perform as
a bellows. The electrical conductor sheets to be covered or be
coated with an insulating material to be minimally vertically
conductive, and/or the opposing heat sink surface should be covered
or coated to be minimally electrically conductive vertically. The
heat sink or conductor placed over the heat sink may be used as a
second electrode.
[0252] Standoffs between each pair of electrical conductors so that
they remain apart unless forced together. These standoffs can be
formed when molding one of either side of the bellows or added to
the structure to the gap as separate components.
[0253] Placing an electrical change between these plates creates an
electric force that can pull the plates together and push air out,
and when release they can pull air in.
[0254] The bellows may be one or more large or long sections that
can push most of the air out from between the conductors, can be a
series of bellows that sequentially are activated by a controller
to push air linearly in any selected direction, and/or can be
configured as one or more smaller bellows that push part of the air
in one direction due to check values built into the air part so air
travels primarily in one direction for each channel.
[0255] If check value are used, they can be prefabricated and
inserted into the channels during assembly, or the check values can
be made as part of the structure when one or both sides of the
channel are moulded. The check vales may be simple flaps with a
preferred direct and be blocked from reversing direction with
molded in ridges.
[0256] High dielectric constant materials such as epoxy/barium
titanate coating composites are preferred over these conductor
plates to reduce the required drive voltage.
[0257] Magnets, conductive coils, and/or ferromagnetic materials
may be substituted for the electric to provide motive force to
these bellows. While bellows pumping mechanisms are known using
similar components to those presented. What makes this structure
unique is the significant and unusual adaptations for use a
flexible array, the built in molded check valves, and being used as
a built in dual purpose heat sink and cooling airflow generator for
large area flexible devices. This cooling mechanism makes it
possible to manufacture low cost, thin, reliable devices than can
remain cooler and/or handle much higher power than reasonable
thickness systems with passive heat removal systems.
[0258] A drawing showing an embodiment of this concept with novel
molded in check valves.
[0259] The present invention, or embodiments thereof which may use
all or parts of the described spectral ranges, is applicable to
non-therapy biological uses of devices including but not limited to
(1) enhancing plant growth, blooming, and/or ripening, (2)
enhancing algae growth, photo-bacteria growth, and other
photosynthesis or other photosensitive biological processes, (3)
microbial stimulation, (4) increasing antimicrobial action on or in
materials using photosensitizers (e.g., water or foods), and/or (5)
visual image enhancement for enhanced detection of materials with
unique light absorption and emission characteristics.
[0260] While the foregoing written description of the invention
enables one of ordinary skill to make and use what is considered
presently to be the best mode or modes thereof, those of ordinary
skill will understand and appreciate the existence of variations,
combinations, and equivalents of the specific embodiment, method,
and examples herein. The invention should therefore not be limited
by the above described embodiment, method, and examples, but by all
embodiments and methods within the scope and spirit of the
invention. The disclosure, as variously set out herein in respect
of features, aspects and embodiments thereof, may in particular
implementations be constituted as comprising, consisting, or
consisting essentially of, some or all of such features, aspects
and embodiments, as well as elements and components thereof, or a
selected one or ones thereof, being aggregated to constitute
various further implementations of the disclosure. The disclosure
contemplates such features, aspects and embodiments in various
permutations and combinations, as being within the scope of the
disclosure. The disclosed subject matter may therefore be specified
as comprising, consisting or consisting essentially of, any of such
combinations and permutations of these specific features, aspects
and embodiments, or a selected one or ones thereof.
* * * * *