U.S. patent application number 11/490868 was filed with the patent office on 2007-02-01 for dual filter multiple pulse photo-dermatological device with pre/post optical heating, quasi-logarithmic spacing, and laser rod spectrum infusion.
Invention is credited to Stephen Almeida.
Application Number | 20070027441 11/490868 |
Document ID | / |
Family ID | 36915481 |
Filed Date | 2007-02-01 |
United States Patent
Application |
20070027441 |
Kind Code |
A1 |
Almeida; Stephen |
February 1, 2007 |
Dual filter multiple pulse photo-dermatological device with
pre/post optical heating, quasi-logarithmic spacing, and laser rod
spectrum infusion
Abstract
Method and apparatus to treat unwanted dermatological conditions
on a specific area of the body. The area of treatment is exposed to
a specific pattern of multi-wavelength light which may have an
added infusion of a particular wavelength from a unique
non-collimated laser rod optical insertion. The light is generated
by specific gas mixture multiple flashlamps that allow
simultaneous, overlap, or consecutive firing with quasi-logarithmic
spacing between pulses. Pre/Post low level optical heating
increases lesion temperature to optimize pulsed treatment. The
optimum fixed specific wavelength distribution pattern allows the
treatment of various skin conditions by adjusting the intensity of
light, and delay between pulses. The need for skin cooling and
damage to skin treatment areas is eliminated by the
quasi-logarithmic pulse spacing in conjunction with optimum length
and characteristic shape of the individual pulses of light.
Inventors: |
Almeida; Stephen; (Tampa,
FL) |
Correspondence
Address: |
BROWN, RUDNICK, BERLACK & ISRAELS, LLP.
BOX IP, 18TH FLOOR
ONE FINANCIAL CENTER
BOSTON
MA
02111
US
|
Family ID: |
36915481 |
Appl. No.: |
11/490868 |
Filed: |
July 21, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10600176 |
Jun 20, 2003 |
7097639 |
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11490868 |
Jul 21, 2006 |
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09841816 |
Apr 25, 2001 |
6595986 |
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10600176 |
Jun 20, 2003 |
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09173422 |
Oct 15, 1998 |
6228074 |
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09841816 |
Apr 25, 2001 |
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Current U.S.
Class: |
606/9 ;
606/16 |
Current CPC
Class: |
A61B 2017/00172
20130101; A61B 2018/1807 20130101; A61B 18/203 20130101; A61B
2018/00452 20130101; A61B 2018/00476 20130101 |
Class at
Publication: |
606/009 ;
606/016 |
International
Class: |
A61B 18/18 20060101
A61B018/18 |
Claims
1. A method for treating various dermatological conditions
comprising the steps of: generating a light that has a specific
wavelength distribution pattern output and intensity; filtering
said light through a first filter and a second filter to construct
an optimum wavelength distribution pattern to encompass multiple
modalities of dermatologic treatment with said light; placing a
hollow reflective light guide with a window against a skin section
forming an optical seal to contain said light; and covering said
skin section with a plume barrier lotion; and illuminating said
skin section by directing said light through said first and second
filters through said hollow reflective light guide through said
plume barrier lotion.
2. The method according to claim 1, wherein said light has a
specific pulse geometry.
3. The method according to claim 1, wherein said light exiting said
hollow light guide has a wavelength greater than 390 nm.
4. The method according to claim 1, wherein said light generated
may be infused with a single wavelength laser rod source.
5. The method according to claim 2, wherein said light source
comprises multiple individual flashlamps which are fired
simultaneously or consecutively with a delay between each said
pulse.
6. The method according to claim 5, wherein said pulses from said
flashlamp are approximately 14 ms in duration.
7. The method according to claim 6, wherein said flashlamp(s) are
fired with progressive logarithmic spacing between said pulses to
eliminate active skin cooling.
8. The method according to claim 5, wherein said flashlamps are
individually powered by an electrical energy supply that is 160-400
joules for every cm2 of output.
9. The method according to claim 1 wherein said light source is
non-laser and radially emitted and photons from said light source
are reflected from said hollow reflective light guide and exit
through said first filter at multiple angles through the light
guide cooling water down said hollow reflective light guide and
through said second filter for further desired wavelength cutoff
and through said hollow reflective light guide into said skin
section at multiple angles.
10. The method according to claim 1, wherein said light source
comprises: a power source(s); single or plurality of flashlamps; a
water or air cooling system; a control source for firing said
flashlamps with logarithmic spacing; and a laser rod head insertion
for single wavelength infusion.
11. The method according to claim 10 wherein said flashlamps
consist of Kr, Xe gas.
12. The method according to claim 1, wherein said hollow reflective
light guide is made of ceramic.
13. The method according to claim 1 wherein said light spectral
output pattern is generated in an output between 390 nm and 1,200
nm.
14. The method according to claim 1 wherein said light spectral
output pattern is generated at a low level pre/post pulse firing
for dermatological lesion pre/post heating.
15. The method according to claim 10, wherein said control source
allows simultaneous, overlap and consecutive firing of said
flashlamps.
16. The method according to claim 10, wherein said flashlamps
consist of synthetically fused quartz doped with cerium oxide.
17. An apparatus for treating a dermatological condition
comprising: a water cooled delivery head; at least one flashlamp
contained within said delivery head wherein said flashlamp produces
a desired light output; an individual energy source connected to
said flashlamp; a control mechanism connected to said individual
energy source said control mechanism allowing for simultaneous,
overlapping and consecutive firing of said flashlamps; a laser rod
inserted into the delivery head for single wavelength light
infusion into said light output; a first light filter and a second
light filter positioned beneath said delivery head wherein said
first and second light filters eliminate selected wavelengths or
portions thereof of said light; and a water cooled hollow
reflective light guide directing said light to a treatment
area;
18. The apparatus of claim 17 wherein said energy source is
provided by battery power.
19. The apparatus of claim 17 wherein said energy source is able to
deliver low level light through said flashlamps for pre/post
dermatological lesion heating.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 10/600,176, filed on Jun. 20, 2003, which is a
continuation-in-part of the U.S. patent application Ser. No.
09/841,816 filed Apr. 25, 2001, which is a continuation-in-part of
U.S. patent application Ser. No. 09/173,422 filed on Oct. 15, 1998,
which is now U.S. Pat. No. 6,228,074 issued on May 8, 2001, which
is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] This invention relates to a method and device for treating
and removing various skin conditions and lesions using flashlamps.
There exists a multitude of common skin problem which can be caused
by many reasons. Conditions such as excessive hair, age spots,
freckles, superficial veins, wrinkles, acne, rosacea and collagen
shrinkage due to old age to name just a few. There are many
products and methods for treating such skin conditions. The methods
can include one or a combination of external creams, chemicals,
internal medications, laser devices, mechanical devices, and
surgery.
[0003] These methods vary in effectiveness, pain, term of benefit,
side effects, duration of treatment, and cost of procedure.
Unfortunately, to treat all the various skin conditions generally
requires multiple devices and/or treatment modalities. Because of
this need for multiple devices and modalities to treat numerous
skin conditions, a single device that could treat a great number of
skin conditions would make treatments more accessible to the
public.
[0004] Prior art methods such as Altshuler et al. U.S. Pat. No.
6,511,475 utilizes continuous wave light as apposed to a pulsed
light system. The Altshuler device does not create high peak
temperatures in a short time span due to its continuous wave
nature. This inability to create high peak temperatures in a short
time span prohibits its use in a wide variety of skin
conditions.
[0005] While another prior art method disclosed in Eckhouse et al.
U.S. Pate. No. 6,514,243 utilizes pulsed light. Its particular
spectrum distribution pattern requires the use of a cooling gel to
prevent discomfort to the patient. Unfortunately, the spectrum
distribution pattern of the Eckhouse device may cause damage to the
treatment area skin. Further, the lack of multiple lamps severely
limit the range of skin conditions that the Eckhouse device is able
to treat.
SUMMARY OF INVENTION
[0006] The present invention provides a method in which a variety
of unwanted dermatological conditions can be removed or treated
without damage to the skin. The device emits a multi-wavelength
spectrum which is absorbed in many chromophores such as melanin,
blood, certain tissue structures, and certain bacteria. Since the
inventive device emits a multi-wavelength spectrum that is absorbed
by many chromophores, the device can treat the following
dermatologic conditions such as but not limited to the following:
blood vessels, pigmented lesions, acne, Rosacea, wrinkles, hair
removal, photo-modulation, collagen rejuvenation, and skin
smoothing.
[0007] One illustrative embodiment of the inventive device allows
the removal of superficial blood vessels from selected areas of the
skin in an efficient and painless manner. According to the
invention, the method of blood vessel removal consists of
delivering a specific pattern of non-laser generated multiple light
wavelengths which pass through the skin and into the blood vessel.
The absorption of these various wavelengths results in thermal and
photochemical damage to the selected vessel and its components. The
multiple wavelengths that are utilized in this treatment occur at
different intensities throughout the wavelength spectrum of about
400 nm to about 1200 nm producing a pattern that achieves optimal
depth penetration.
[0008] The multiple wavelength spectrum, according to the
invention, is produced by four flashlamps consisting of a specific
mixture of krypton and xenon gas encased by a cerium oxide doped
synthetically fused quartz envelope. The four flashlamps are
connected to separate user intensity controlled power supplies that
are specifically designed to produce approximately a 14 ms pulse
duration with a specific pulse discharge pattern to accommodate
different size dermatologic targets. Electrical supply energies of
160-400 joules are input to the flashlamps per cm.sup.2 of output.
It is contemplated within the scope of the invention that the
electrical supply energy can be generated with typical household or
commercial current or can be generated by the use of battery
power.
[0009] Each flashlamp can be fired simultaneously, with an overlap,
or with a time duration of up to about 40 ms between each pulse.
The spacing between each pulse grows consecutively larger to
regulate tissue temperature avoiding unwanted tissue damage. This
spacing technique eliminates the need for epidermal cooling and
topical anesthetics preventing injury and pain to the patient.
[0010] The four flashlamps form a pulse train of four individual
pulses which results in a treatment shot. Each treatment shot is
separated by approximately 3 second intervals to allow the user to
move the delivery system to another area of the body for subsequent
treatment. The pulse length and characteristic shape of each
individual pulse is designed to distribute the energy over a period
of time that substantially eliminates damage to the skin that can
occur in prior art methods.
[0011] The inventive device allows adjustment to the intensity of
the light source and delay between each individual pulse. The
adjustment of the intensity and delay of the light source allows
the user to adjust the treatment shot to accommodate different skin
and dermatologic target types.
[0012] The flashlamps utilized in the inventive device are housed
in a polyester head. It is contemplated within the scope of the
invention that the flashlamp housing may be fabricated from
materials known in the art. The flashlamp head is connected to a
hollow internally reflective rectangular light guide by means of a
400 nm high pass filter. There exists a clear window on the rim of
the light guide to stop plume from the skin from contaminating the
reflector. The light guide is pressed against the skin forming an
optical seal. The non-collimated light, consisting of wavelengths
greater than about 400 nm, passes through the 400 nm high pass
filter and reflects at infinite angles down the hollow light guide
into the skin reaching the skin, tissue, and dermatological
targets.
[0013] In an alternative illustrative embodiment of the inventive
device, modification to the output wavelength pattern of the
apparatus, by the use of a different light filter, allows the
apparatus to be effective in destroying particular dermatological
targets and lesions.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The foregoing and other features and advantages of the
present invention will be more fully understood from the following
detailed description of illustrative embodiments, taken in
conjunction with the accompanying drawings in which:
[0015] FIG. 1 is a cross sectional view of the delivery head of the
device which generates and delivers the multiple wavelengths to the
hair and its components and a block diagram of the power supplies
and controlling electronics which control the lamps in the delivery
head;
[0016] FIG. 2 is a cross sectional view of the delivery head with
apparatus for laser rod spiking of output wavelength;
[0017] FIG. 3 shows the cross sectional view of the delivery head
and light guide with conceptual function:
[0018] FIG. 4A shows the manipulated pulse geometry of the
invention;
[0019] FIG. 4B shows basic circuit components to form pulse
geometry and create optical pre/post heating of dermatological
targets;
[0020] FIG. 5A shows the basic circuitry to create the
quasi-logarithmic pulse spacing according to the invention;
[0021] FIG. 5B shows a steep logarithmic charge curve which creates
short quasi-logarithmic spacing according to the invention;
[0022] FIG. 5C shows a shallow logarithmic charge curve which
creates long quasi-logarithmic spacing according to the
invention;
[0023] FIG. 5D shows how quasi-logarithmic spacing reduces peak
temperatures as compared to linear spacing.
[0024] FIG. 6a shows the quad pulse train of each treatment shot
and the controlled delay between each pulse;
[0025] FIG. 6b shows the quad pulse train of each treatment shot
with a negative delay that signifies overlap;
[0026] FIG. 7A is the relative intensity pattern of wavelengths
generated by the invention;
[0027] FIG. 7B shows melanin absorption throughout the spectrum
region;
[0028] FIG. 7C shows blood absorption throughout the spectrum
region;
[0029] FIG. 7D shows depth penetration throughout the spectrum
region;
[0030] FIG. 7E shows blood absorption, melanin absorption, and
depth penetration with respect to device wavelength output; and
[0031] FIG. 8 shows temperature effect of pre/post optical
lesion.
DETAILED DESCRIPTION
[0032] Referring in detail to the drawings, a flashlamp apparatus,
according to the present invention is shown in FIG. 1. The water
cooled delivery head 10 containing multiple flashlamps 1 each
having an individual power source capable of timed firing 20 that
creates the light output for dermatologic treatment which exits
through the light guide window 14. The multiple flashlamps 1 each
contain a combination of approximately 90% krypton gas and 10%
xenon gas. This gas combination creates a specific spectral
distribution pattern.
[0033] The container material of the flashlamps 1 is comprised of
synthetic quartz to eliminate impurities. The use of synthetic
quartz prevents the degradation of the flashlamps 1 after prolonged
use. Additionally, the synthetic quartz is doped with cerium oxide
in order to block ultraviolet light under 390 nm from the lamp and
thereby maintaining the integrity of a reflective chamber 5 and
high pass filters 7, 9. The cerium doping also has the ability to
convert ultraviolet light, which would normally become waste heat,
into higher wavelengths which can pass through the high pass
filters 7, 9 to create a more efficient conversion of electrical
energy to light output.
[0034] The reflective chamber 5 is made of a metallic or ceramic
material whose reflectivity coincides with the desired output of
wavelengths greater than high pass filters 7, 9. In one
illustrative embodiment gold is used to construct the reflective
chamber 5. Gold reflects over 95% of light at about 610 nm and
higher wavelengths while reflecting approximately 60% of light at
lower wavelengths. In performing hair removal, the desired
wavelength output is greater than about 610 nm. The reflectivity of
gold partially absorbs the lower wavelengths in the reflective
chamber 5 so the high pass filter 9 does not bear the full
absorption of the lower wavelengths which may result in damage to
the high pass filter 9. Other reflective materials that are well
known in the art can be used to construct the reflective chamber 5
these materials include, but are not limited to brass, copper,
plastic, and ceramic or the like.
[0035] In an alternative illustrative embodiment a full spectrum
reflectant ceramic is used in the reflective chamber 5 and light
guide 4. By using two filters 7, 9 with long pass filters 610 nm
and 495 nm respectively, a spectral distribution pattern can be
constructed to be effective on multiple dermatologic modalities.
The delivery head 10 is cooled by water which flows in through an
inlet port 2 and fills a first chamber 6, the water then flows over
the flashlamps 1 into the reflective chamber 5 and simultaneously
in lightguide 4 by way of water channel 12. The water then flows
into chamber 11 by way of reflective chamber 5 and water channel
13. Once the water enters chamber 11, it then exits out of delivery
head 10 through an outlet port 3. The water, which flows through
the delivery head 10, is recycled in a closed cooling system having
a radiator and fan assembly, which uses room air as the heat
exchange. The cooling system should maintain water temperatures
surrounding the flashlamps 1 below a maximum continuous operating
temperature of about 100 degrees Celsius. Since the electrodes of
flashlamps 1 create the greatest heat, chambers 6 and 11 allow a
greater volume of water and thus thermal exchange over these
areas.
[0036] One illustrative embodiment of the present invention uses an
optically transparent epoxy coating 8 to coat the metallic
reflector preventing oxidation and degradation from the water
cooling that flows through the delivery head 10. The water is used
solely to cool the lamps 1, reflective chamber 5, long pass filters
7, 9, and light guide 4. The water is kept in the system by light
guide window 14 which is used sealed to the light guide 4.
[0037] The warm water cooling does not cool the skin at light guide
window 14. The pulse shape, pulse length, and quasi-logarithmic
pulse spacing, further explained in FIGS. 4, 5, 6 eliminate the
need for skin cooling. Another illustrative embodiment utilizes
high volume forced air instead of water to cool the delivery head
10. This embodiment severely sacrifices repetition rate of firing
and total power output capabilities but may be used in a low power
portable device. It is contemplated within the scope of this
invention that the forced air may be cooled prior to introduction
to the delivery head to improve the removal of heat.
[0038] The commercially available high pass filters 7, 9 known to
those skilled in the art transmits only wavelengths above their set
value. A typical 400 nm high pass filter can be use includes but is
not limited to a CVI LASER (Model# GCG-GG-400-1.00) In one
illustrative embodiment of the invention, 400 nm and 630 nm high
pass filters 7, 9 are used. Any wavelengths that pass through the
filters 7, 9 below the filter value are absorbed and converted to
heat. The cooling water in the reflective chamber 5 and light guide
4 are also in contact with high pass filters 7, 9 extracting heat
due to the lower wavelength absorption. The high pass filters 7, 9
only allows wavelengths above 400 nm and 630 nm respectively to
enter into the hollow reflective light guide 4.
[0039] A power source and firing apparatus 20 are connected to the
delivery head 10. The flashlamps 1 are connected to high voltage
switches 25. Each flashlamp 1 is connected to its own power supply
17 via the high voltage switches 16. Each power supply 17 supplies
approximately 40 to 100 joules of electrical energy to each
flashlamp 1 of every cm.sup.2 of output. A firing sequence control
19 is used to activate a trigger 16 for each flashlamp 1 in a
simultaneous or consecutive order. An output intensity control 24
regulates the electrical energy of the individual power supplies
17, which discharge through the flashlamps 1. The firing sequence
control 19 regulates the amount of time it takes for the output
energy of one treatment shot to be dispersed while the output
intensity control 24 regulates the amount of energy delivered.
[0040] In one illustrative embodiment a single lamp 1 is connected
to each high voltage switch 25. This system switches each power
supply 17 to the same lamp This embodiment can only be used for
consecutive firing and lower power due to the single lamp
limitations.
[0041] Referring to FIG. 2 a cross sectional view of the delivery
head with laser rod spectrum spiking is shown. In one embodiment of
the invention, a laser rod 31 is inserted in the light guide. The
laser rod 31 is coated on both sides with a 75% reflective coating
32. The wavelength of the reflective coating 32 will be matched to
the wavelength of the laser rod 31 chosen for spectrum spiking
(e.g. Nd:YAG laser rod 31 emits a wavelength of 1064 nm, so the
reflective coating 32 must match this wavelength for function).
When the device is fired, the lamps 30 excite the laser rod 31 and
create laser action by photons reflecting back and forth between
the 75% reflective coatings 32. Since the coating 32 is 75%
reflectant, the laser rod 31 will emit single wavelength laser
light at both ends of the laser rod 31 entering into the reflective
chambers 33. The reflective chambers 33 will be geometrically
designed to reflect the laser output forward through the light
guide 34.
[0042] In one embodiment of the invention, the reflective chamber
33 will be formed out of a diffuse reflecting ceramic. This will
provide homogeneous distribution of photons at the light guide exit
34. Since the lamps of the device 30 emit multi-wavelength light,
many different absorbing types of laser rods 31 may be inserted
into the device to choose the desired single wavelength
spiking.
[0043] Referring to FIG. 3 a cross sectional view of an alternative
delivery head is shown. The light source from the flashlamps 36
passes through the flashlamp cooling water 39 and is represented
here by individual photons 38. Water coolant 39 is used to extract
heat from the lamp light source 36 which flows into reflective
chamber 35, through water channel 48, into light guide 46, and back
into reflective chamber 35. Since the light source 36 is non-laser,
and radially emitted, the photons 38 are reflected from the
reflective chamber 38 and exit through the high pass filter 40
(assuming the wavelength is higher than the filters cutoff
wavelength), at multiple angles 45, through the light guide cooling
water 39, down the reflective light guide 46, through the second
high pass filter 51 for further desired wavelength cutoff, through
light guide window 49, then through a plume barrier lotion, and
into the skin 54 at multiple angles 44 reaching various
dermatological sights such as pigmented lesions 53, vascular
lesions 52, acne 50, and the hair and its components 47 after
scattering through the skin 43. Light that is reflected back from
the skin 37 enters back into the light guide 46 and reflective
chamber 35. Since the chamber and light guide are highly
reflective, the photons that reflect off of the skin 37 will be
re-directed back to the skin 37 and re-used for more
efficiency.
[0044] The plume barrier lotion 41 is a transparent non-cooling
lotion preventing plume from the heated skin and lesions from
carbonizing and sticking to the light guide window 49. The hollow
reflective light guide 46 is made of a non corrosive metallic or
ceramic highly reflective material. The light guide window 49 is
pressed against the skin 42 forming an optical seal preventing the
escape of light outside the light guide. The light guide window 49
prevents plume from the heated skin and lesions from entering into
and contaminating the reflective light guide 46. This optical seal
ensures all energy is transmitted through the skin and into the
skin and dermatological targets. Any hair is trimmed or shaved 47
prior to treatment so as to have no hair above the outer layer of
skin that would absorb the light and block its transmission into
the skin.
[0045] Turning now to FIG. 4A, a graphic representation of the
pulse geometry and the pulse train sequence of the instant
invention is shown. FIG. 4A shows the formula for damping factors
60 that create various pulse geometries 61 shown in the graph. The
desired pulse geometry that provides the most efficacious results
for destruction and treatment of dermatological lesions is a
damping factor of three (3), which provides an elongated pulse 62.
This pulse geometry takes advantage of the difference in thermal
relaxation times of skin lesions and skin.
[0046] Thermal relaxation time is the time it takes for a body of
particular size, shape, and material to dissipate 50% of its heat
energy. The physical law is represented by equation 66 where d is
the diameter of the body, g is the geometric factor, and k is the
thermal diffusivity factor of the material. This specific pulse
geometry as depicted in FIG. 4a, spreads the energy more evenly
throughout the pulse length T 63 which is approximately 14 ms for
the device. Since the thermal relaxation time of skin is
approximately 10 ms, having the pulse duration over about 10 ms
prevents damage to the skin by allowing treated skin to dissipate
energy and thereby avoiding damaging high temperatures. Although a
14 ms individual pulse duration is used on the application device,
it is contemplated within the scope of the invention that any pulse
duration between 10 ms and 60 ms would provide a similar
effect.
[0047] A further advantage of the pulse geometry according to the
invention is to take advantage of various size dermatological
lesions and components. Since dermatological lesion sizes vary in
any particular area of the body, so do their corresponding thermal
relaxation times. The optimum pulse duration and geometry would be
one that can be effective on the broad size dermatological lesions
while sparing damage to the surrounding tissue. The average size
dermatological lesion will vary in thermal relaxation times from 10
ms to 150 ms. By using this specific pulse geometry, optimum damage
is confined to the dermatological lesion for large and small sizes.
Small lesions having a thermal relaxation time of 20 ms would
dissipate the heat into the surrounding tissue rapidly resulting in
a lower peak temperature in the hair follicle and creating high
temperatures in the tissue. By using this specific pulse geometry
62, greater then 70% of the energy is delivered in the first half
of the pulse T1 64 while the remaining energy is dispersed in the
second half of the pulse T2 65. This still allows adequate cooling
time for the skin but creates higher temperatures in the small
lesions since most of the energy is delivered in a short amount of
time not allowing the lesion time to disperse the energy to the
surrounding tissue. Large lesions having higher thermal relaxation
times up to 150 ms are also affected since even more time is
required to disperse the energy.
[0048] Referring to FIG. 4B, a schematic of the flashlamp circuit
75 necessary to accomplish desired pulse geometries pre/post lesion
heating is shown. A high voltage spike is generated by a trigger
transformer circuit 73. The trigger circuit 73 ionizes a flashlamp
79 so that a 600V simmer circuit 76 keeps the flashlamp 79
continuously illuminated at a low level. A voltage supply 70
charges a capacitor 71. When a high voltage switch 74 is activated,
a capacitor 71 discharges through a diode bank 78 and an inductor
72 into the flashlamp 79. The flashlamp has a certain resistance
known as Ko. The values of the components in the circuit 75 must
provide a damping factor of three (3) when inserted into formula 60
and also provide a pulse duration T, as shown in FIG. 4A, 63 of 14
ms.
[0049] Referring to FIG. 5A a circuit that generates
quasi-logarithmic pulse spacing is shown. The circuit is powered by
a 12 DC power supply 88. To start the triggering sequence of the
flashlamps used in the invention, electronic controls 81 send a
signal out to a solid state electronic switch 82 commencing the
sequence. When the electronic switch 82 is closed, a capacitor 85
is charged through a low set resistor 83 and a duration control
resistor knob 84. These resistors 83, 84 control the charge rate of
the capacitor 85. The low set resistor 83 sets the minimum charge
rate when the pulse train duration knob 84 is set to the minimum
value. The 1 to 10V linear sequencer 86 is a voltage bar graph
meter that increases 1 step for every 1 volt 87 detected on the
capacitor 85. Since the capacitor 85 charges at a logarithmic rate,
there will be an increase in time between each 1V step. When the
sequenced output T1-T5 87 is used to trigger each flashlamp, there
is also an increase of time between the firing of each flashlamp.
This timing technique creates the quasi-logarithmic pulse
spacing.
[0050] Referring to FIGS. 5A and 5B, the charge curve 90 of the
quasi-logarithmic circuit capacitor 85 is shown. The voltages on
the Y axis of the graph from 2 to 6 volts corresponds to the 1-10 v
linear sequencer output 86 Fig. the timing in (ms) indicated on the
X axis of FIG. 5B 91, 92, 93, 94, 95 as it corresponds with the
charge curve 90, indicates the spacing between each flashlamp pulse
when the duration control 84 is set to a certain setting.
[0051] FIG. 5C depicts the spacing 101, 102, 103, 104, 105 between
each flashlamp pulse when the duration control 84 FIG. 5A is set to
a higher setting than that shown in FIG. 5B. A higher setting of
the duration control 84 as depicted in FIG. 5A, will create a
shallower charge curve 100 than a lower duration control 84 setting
curve 90 FIG. 5B.
[0052] FIG. 5D shows the temperature effect on tissue from
quasi-logarithmic spacing. The tissue temperature for normal linear
spacing is depicted in curve 110. With linear spacing, the time
between each pulse 114 is equal. With quasi-logarithmic spacing,
the tissue temperature is depicted in curve 111. The spacing
between each pulse 115 in quasi-logarithmic spacing is greater with
each consecutive pulse. The peak temperature in tissue for linear
spacing 112 is higher than that with quasi-logarithmic spacing 113.
Since the tissue has a greater time between each pulse 115, more
time is allowed to conduct heat to surrounding tissue and lower the
peak temperature. This lower peak temperature 113 decreases the
risk of scarring and skin damage.
[0053] Referring to FIG. 6A, a treatment shot is shown according to
the invention when the treatment shot is set for consecutive firing
with delays between each pulse 124. The treatment shot consists of
a four-pulse sequence train with a time delay between each pulse
121. A single pulse 123 is fired from the apparatus with a time
delay of T 120 before the next consecutive pulse in the four-pulse
train is triggered. If T 120 is greater than a single pulse
duration (SPD) 125, which is approximately 14 ms, then a delay D
121 is created between each pulse. This delay 121 between each
pulse allows the skin to cool before then next consecutive pulse is
triggered. The total time it takes the apparatus to deliver the
energy is T 122 which is the combination on all the delays 121 and
all the SPDs 124. This time T 122 is the duration of the treatment
shot. Each treatment shot is separated by a three-second interval
to allow the user to move the delivery head to the next consecutive
area for treatment.
[0054] One illustrative embodiment utilizes optical pre/post lesion
heating. This optical pre/post heating consists of the flashlamps
emitting a continuous low level light output 137 of the same
wavelength characteristics as the single pulse output before and
after each pulse. This low level output 137 is present between each
pulse.
[0055] Referring to FIG. 6B that depicts a treatment shot from the
apparatus when the treatment shot is set for overlap firing. The
treatment shot consists of an overlap of single pulses in the
four-pulse train 130. Since the flashlamps are connected to
separate power supplies, the apparatus is capable of overlapping
pulses. If a single pulse is fired from the apparatus 135 with a
consecutive triggering time delay T 131 which is shorter than the
SPD 134, then a negative delay (-) D 132 is created which
represents an overlap of the consecutive pulses. This overlap
transforms the four single pulses into a single sawtooth appearing
pulse 136 of duration T 133. This single sawtooth pulse 136 allows
more energy in a shorter amount of time T 133 than a single lamp
system incapable of overlap. This higher energy in a shorter amount
of time allows for more treatment options. The pre/post optical
heating 137 is also an option with overlap firing of pulses.
[0056] Referring now to FIG. 7A, a spectral output pattern
according to the invention is shown. The relative intensity
spectral output distribution pattern 140 of the device is designed
to simulate a bell curve throughout the useful spectrum of about
400 nm to about 1200 nm by creating central peaks of high intensity
144 while tapering off the lower and higher wavelengths 142. This
spectral output distribution pattern creates an optimum output
which benefits are explained in detail in FIG. 7E. The effect of
the small second high pass filter as depicted in FIG. 1 is shown by
the dotted wavelength cutoff section 141. Since this second small
filter does not completely block the light entering the light
guide, it only reduces the wavelengths below the cutoff value of
the filter, not block them. The result of the dual filters is shown
by a first curve 142. A second curve 141 is the wavelength output
without the second filter. The benefit of the dual filters as shown
in FIG. 1 is to further modify the spectral output pattern 140 to
be useful on all types of dermatologic lesions without the need to
change filters.
[0057] Referring to FIG. 7B which demonstrates the absorption of
light in melanin throughout the wavelength spectrum. A logarithmic
curve 150 shows how melanin absorption decreases as the wavelength
increase. Since melanin is the absorbing chromophore in many
dermatological targets, the logarithmic curve 150 demonstrates how
more energy is necessary to heat up a target as the wavelength
increases due to absorption factor. The reaction of the device
output FIG. 7A as it corresponds to melanin absorption is shown in
detail in FIG. 7E.
[0058] Referring to FIG. 7C, the absorption of light in blood
throughout the wavelength spectrum is depicted. Absorption of light
by blood is very high from about 400 nm to about 475 nm 160 with a
high peak of absorption from about 500 nm to about 600 nm 161.
Wavelengths above 650 nm have very little absorption by blood.
Blood is the absorbing chromophore for vein and angioma removal as
well as stimulating collagen growth. Collagen growth is
accomplished by heating blood and stimulating fibroblasts. This
reaction also decreases wrinkles and smoothes the skin as a result.
The graph shows how the lower wavelengths 160, 161 are necessary
for blood based dermatological targets. The reaction of the device
output FIG. 7A as it corresponds to blood absorption is shown in
detail in FIG. 7E.
[0059] Referring to FIG. 7D which graphically depicts the
penetration depth of light versus its wavelength. Since hair
follicles and other dermatological targets are located deep in the
dermis, depth penetration of the incident light is important. The
output of the flashlamps is designed to generate a large amount of
deep penetrating wavelengths. The majority of the output
wavelengths 144 as shown in FIG. 7A of the flashlamps exhibit very
good depth penetration as shown in an area 173 of the graph. This
depth penetration allows incident light to reach deep
dermatological targets and their components. Lower wavelengths 170
have very high melanin absorption FIG. 7B and blood absorption FIG.
7C, but have very little depth penetration 170. This makes low
wavelengths well suited for shallow veins and pigmented based
targets. Mid-wavelengths 171 have very low blood absorption FIG. 7B
and medium melanin absorption FIG. 7A. These mid-wavelengths 171
are not good for veins, but work well for pigmented based targets
and hair removal. The higher wavelengths 172 show little melanin
and blood absorption FIG. 7B, 7C, but very deep penetration. These
higher wavelengths 172 are well suited for deep melanin based
targets at high energy and any dermatological targets that exist
past 1 mm depth in the skin and tissue.
[0060] Referring to FIG. 7E that shows the spectral distribution
183 according to the invention as it corresponds to the absorption
factors of different dermatological targets such as melanin 180,
blood 181, and depth penetration 182. The spectral distribution
pattern of the invention 183 covers all aspects of different
dermatological chromophore absorptions throughout the spectrum that
allows a multitude of various dermatological conditions to be
treated with one all-encompassing wavelength output.
[0061] Turning to FIG. 8, the thermal effect of pre/post optical
heating is depicted. Without pre/post optical heating the skin and
lesion are at the same temperature 190 prior to pulse firing 199.
During pulse firing, the skin increases in temperature 191 along
with the lesion 192. The lesion temperature 192 is greater than the
skin temperature 191 due to higher absorption of the light during
the optical pulse. With pre/post optical heating, the lesion
temperature 194 prior to pulse firing 199 is higher than the skin
temperature 193. When the pulse fires 199 with pre/post optical
heating, the lesion temperature 196 increases to a much higher
level then without pre/post heating 192 due to the fact that the
temperature of the lesion was higher before the pulse. The skin
temperature 195 increases only slightly more after pulse firing 199
than without pre/post optical heating 191 since the skin has little
absorption of light. The change of temperature of the skin 198 with
and without pre/post optical heating is much less than the change
of temperature of the lesion 197 with and without pre/post optical
heating. The pre/post optical heating results an increased lesion
temperature 196 and damage with minimum increase in skin
temperature 195 and damage to provide more effective treatment
results.
[0062] Although the apparatus described in the illustrative
embodiment herein contains four flashlamps, it should be
appreciated by those skilled in the art that the delivery head of
the apparatus may contain more or less than four flashlamps
depending on the application and the area of treatment. Similarly,
the pulse train may consist of more or less than four pulses
depending on the characteristic and severity of various
dermatological conditions that are to be treated. In addition, the
ratio and amount of krypton and xenon in the flashlamps may be
altered to produce a slightly different wavelength output pattern
or various light filters that are well known in the art may be used
to eliminate unwanted wavelengths.
[0063] The foregoing has been a description of illustrative
embodiments of the present invention. The present invention is not
to be limited in scope by the illustrative embodiments described
which are intended as specific illustrations of individual aspects
of the invention, and functionally equivalent methods and
components are within the scope of the invention. Indeed, various
modifications of the invention, in addition to those shown and
described herein will become apparent to those skilled in the art
from the foregoing description. Such modifications are intended to
fall within the scope of the appended claims.
* * * * *