U.S. patent application number 12/916105 was filed with the patent office on 2011-05-26 for method and system for controlling non-coherent pulsed light.
This patent application is currently assigned to Lumenis Ltd.. Invention is credited to Haim Epshtein, Yoni Iger, Shimon Panfil, Boris Vaynberg.
Application Number | 20110125227 12/916105 |
Document ID | / |
Family ID | 34135317 |
Filed Date | 2011-05-26 |
United States Patent
Application |
20110125227 |
Kind Code |
A1 |
Vaynberg; Boris ; et
al. |
May 26, 2011 |
Method and System for Controlling Non-Coherent Pulsed Light
Abstract
A system and method to control non-coherent pulsed light, the
system including a lamp to produce non-coherent light energy in a
pulsed mode, a current supply to provide energy to the system, and
a switching module to control the spectral distribution and/or
light intensity in the non-coherent pulsed light energy during a
pulse of non-coherent light. The system may include a controller
unit to control pulse parameters for a selected treatment, based on
illumination data received from the light sensor. The system may
include one or more changeable filters to modulate the pulses
supplied to the lamp during a pulse.
Inventors: |
Vaynberg; Boris; (Zichron
Ya'akov, IL) ; Epshtein; Haim; (Benyamina, IL)
; Panfil; Shimon; (Haifa, IL) ; Iger; Yoni;
(Haifa, IL) |
Assignee: |
Lumenis Ltd.
Yokneam
IL
|
Family ID: |
34135317 |
Appl. No.: |
12/916105 |
Filed: |
October 29, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10916637 |
Aug 12, 2004 |
7846191 |
|
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12916105 |
|
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60494098 |
Aug 12, 2003 |
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Current U.S.
Class: |
607/88 |
Current CPC
Class: |
A61B 2018/00458
20130101; A61B 18/18 20130101; A61B 2018/1807 20130101; A61N 5/0616
20130101; A61N 5/0617 20130101; A61B 18/203 20130101; A61B
2018/00476 20130101; A61B 2018/00452 20130101 |
Class at
Publication: |
607/88 |
International
Class: |
A61N 5/06 20060101
A61N005/06 |
Claims
1.-69. (canceled)
70. A system comprising: a lamp to produce non-coherent pulsed
light; a current supply to provide current to the lamp; and a
controller to control at least the lamp to enable provision of
controlled spectral distribution and controlled temporal intensity
distribution of the non-coherent pulsed light within a pulse of the
non-coherent pulsed light, the controlled spectral distribution in
the non-coherent pulsed light and the controlled temporal intensity
distribution of the non-coherent pulsed light being controlled by
altering current delivered to the lamp to alter at least one of the
spectral distribution and the temporal intensity distribution
during the pulse of the non-coherent light.
71. The system of claim 70, further comprising: a feedback
mechanism including the controller, the feedback mechanism
configured to perform a determination whether sensor data from one
or more sensors is in accordance with a treatment plan, the
feedback mechanism further being configured to change the treatment
plan to alter, based on the determination of the feedback
mechanism, the current delivered to the lamp to alter the at least
one of the spectral distribution and the temporal intensity
distribution of the non-coherent pulsed light during the pulse,
wherein the sensor data includes one or more of: output from a
light sensor resulting from application of the pulse of
non-coherent light on a target area, current data from a current
sensor, and temperature data from a temperature sensor.
72. The system of claim 71, wherein the feedback mechanism is
configured to determine whether the spectral distribution of the
non-coherent pulsed light is in accordance with a predetermined
spectral shift of the spectral distribution, and to alter the
spectral distribution during the pulse in accordance with the
predetermined spectral shift of the spectral distribution.
73. The system of claim 71, wherein the feedback mechanism
comprises at least one light sensor to: sense the non-coherent
pulsed light produced by the lamp, generate signals based on the
sensed non-coherent pulsed light, and provide the generated signals
to the feedback mechanism.
74. The system of claim 70, further comprising: one or more
capacitors and a capacitor charger to provide energy to the lamp,
and a current regulator to control the current delivered to the
lamp during the pulse of the non-coherent light.
75. The system of claim 74, wherein the regulated current delivered
to the lamp includes one or more of: the current from the power
supply, and current provided by the one or more capacitors.
76. The system of claim 74, wherein the current regulator comprises
a switching module to modulate the current supplied to the
lamp.
77. The system of claim 76, wherein the switching module is
configured to modulate the current delivered to the lamp during a
sub-pulse of the non-coherent light.
78. The system of claim 70, wherein the current supply is
configured to cause substantial maintaining of a selected level of
the spectral distribution during the pulse of the non-coherent
light.
79. The system of claim 70, wherein the current supply is
configured to cause substantial maintaining of a selected level of
the temporal intensity distribution during the pulse of the
non-coherent light.
80. The system of claim 70, further comprising: one or more filters
to enable provision of the controlled spectral distribution of the
non-coherent pulsed light within the pulse of the non-coherent
pulsed light.
81. The system of claim 80, wherein the one or more filters include
one or more of: cut-on filters, cut-off filters, band-pass filters,
changeable filters, neutral density filters, and variable
filters.
82. The system of claim 80, wherein the one or more filters enable
the provision of the controlled temporal intensity distribution of
the non-coherent pulsed light within a pulse of the non-coherent
light.
83. A method comprising: generating by a lamp powered, at least in
part, by a controllable current supply non-coherent pulsed light;
and controllably altering current delivered to the lamp during the
emission of a pulse of the non-coherent light to control at least
one of spectral distribution and temporal intensity distribution of
the non-coherent pulsed light within the pulse of the non-coherent
light.
84. The method of claim 83, further comprising: determining whether
sensor data from one or more sensors is in accordance with a
treatment plan; and changing the treatment plan to alter, based on
the determination of whether the sensor data from the one or more
sensors is in accordance with the treatment plan, the current
delivered to the lamp to alter the at least one of the spectral
distribution and the temporal intensity distribution of the
non-coherent pulsed light during the pulse; wherein the sensor data
includes one or more of: output from a light sensor resulting from
application of the pulse of non-coherent light on a target area,
current data from a current sensor, and temperature data from a
temperature sensor.
85. The method of claim 84, wherein determining whether the sensor
data from the one or more sensors is in accordance with the
treatment plan comprises: determining whether the spectral
distribution of the non-coherent pulsed light is in accordance with
a predetermined spectral shift of the spectral distribution; and
altering the spectral distribution during the pulse in accordance
with the predetermined spectral shift of the spectral
distribution.
86. The method of claim 84, wherein determining whether the sensor
data from the one or more sensors is in accordance with the
treatment plan comprises: sensing the non-coherent pulsed light
produced by the lamp; generating signals based on the sensed
non-coherent pulsed light; and providing the generated signals to a
feedback mechanism.
87. The method of claim 83, further comprising: controlling the at
least one of the spectral distribution and the temporal intensity
distribution of the non-coherent pulsed light within the pulse of
the non-coherent light using one or more filters.
88. The method of claim 87, wherein the one or more filters include
one or more of: cut-on filters, cut-off filters, band-pass filters,
changeable filters, neutral density filters, and variable filters.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority from U.S. Provisional
Patent Application No. 60/494,098, filed Aug. 12, 2003, entitled
"METHOD AND SYSTEM FOR CONTROLLING NON-COHERENT PULSED LIGHT",
which is incorporated in its entirety herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to methods and devices useful
in providing non-coherent pulsed light. Specifically, embodiments
of the present invention relate to systems and apparatuses that
enable controlling the delivery of non-coherent pulsed light.
BACKGROUND
[0003] Light therapy generally involves applying light energy to
increase the local temperature at a target location in a body, as a
result of the absorption of photons distributed in the target
tissue. The photon distribution, and therefore local temperature
rise, is generally determined by the features of the light source
and physical properties of the medium used for conveying the light
to a target. Selective Photothermolysis Theory (SPT), which may be
a physical foundation for many light treatments, typically involves
choosing parameters of the therapeutic light being used, for
example, wavelength, pulse magnitude and pulse duration, etc., in
such way that the temperature rise is sufficiently large to incur
required effects in a target, yet remain below a safety threshold
in the surrounding tissues.
SUMMARY OF THE INVENTION
[0004] There is provided, in accordance with an embodiment of the
present invention, a system to control non-coherent pulsed light,
the system including a lamp to produce non-coherent light energy in
a pulsed mode, a power supply to provide energy to the system, a
capacitor to generate current in the lamp; and a current modulator
to modulate energy flow between the power supply and the lamp. The
system may include a controller unit to control pulse parameters
for a selected treatment, based on illumination data received from
the light sensor. The system may include a switching module to
modulate power supplied to the lamp during a pulse. The system may
include one or more changeable filters to modulate the pulses
supplied to the lamp during a pulse.
[0005] According to some embodiments of the present invention, a
method to control non-coherent pulsed light may include generating
a pulse to provide treatment to a selected target according to a
treatment plan, sensing the light output from the target,
processing sensed signals to determine if the light output complies
with predetermined pulse parameters and/or biological
characteristics, and if the predetermined pulse parameters and/or
biological characteristics are not being met, controlling the
spectral distribution and/or the light intensity of the light
output during a pulse.
[0006] According to some embodiments of the present invention,
treatments with multiple modes of operation within a pulse may be
implemented, to enable differentiation between target and
surrounding tissue. Such treatments may help improve the safety
and/or efficacy of treatments of targets located in dark skin
types, of targets having physical properties similar to or only
slightly different from surrounding tissue, of targets located deep
in the dermis, and/or any combinations of the above treatments.
Furthermore, treatment for hair removal, blood vessel modification,
textural lesions and/or other procedures may be aided using
treatments with multiple modes of operation within a pulse, as
described above.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The principles and operation of the system, apparatus, and
method according to the present invention may be better understood
with reference to the drawings, and the following description, it
being understood that these drawings are given for illustrative
purposes only and are not meant to be limiting, wherein:
[0008] FIGS. 1A and 1B are a schematic illustrations of components
of a non-coherent pulsed light system, according to some
embodiments of the present invention;
[0009] FIG. 2 is a flow chart illustrating a method of controlling
non-coherent pulsed light output according to some embodiments of
the present invention;
[0010] FIGS. 3A-3E are graphical illustrations of light output as a
function of time, according to some embodiments of the present
invention; and
[0011] FIGS. 4A-4C are examples of measured spectra of light output
of, for example, a xenon lamp, as a function of energy input
according to some embodiments of the present invention.
[0012] It will be appreciated that for simplicity and clarity of
illustration, elements shown in the drawings have not necessarily
been drawn to scale and are being provided as non-limiting
examples. For example, the dimensions of some of the elements may
be exaggerated relative to other elements for clarity. Further,
where considered appropriate, reference numerals may be repeated
among the drawings to indicate corresponding or analogous elements
throughout the serial views.
DETAILED DESCRIPTION OF THE INVENTION
[0013] The following description is presented to enable one of
ordinary skill in the art to make and use the invention as provided
in the context of a particular application and its requirements.
Various modifications to the described embodiments will be apparent
to those with skill in the art, and the general principles defined
herein may be applied to other embodiments. Therefore, the present
invention is not intended to be limited to the particular
embodiments shown and described, but is to be accorded the widest
scope consistent with the principles and novel features herein
disclosed. In other instances, well-known methods, procedures, and
components have not been described in detail so as not to obscure
the present invention.
[0014] In the following detailed description, numerous specific
details are set forth in order to provide a thorough understanding
of the present invention. However, it will be understood by those
skilled in the art that the present invention may be practiced
without these specific details.
[0015] Embodiments of the present invention may provide systems and
methods to enable controlling of non-coherent pulsed light emitted
by a light source, such as a lamp, thereby modulating the temporal
distribution of the light and/or the spectral distribution output
by the lamp within a pulse of light. The controlled current may
enable, for example, changing the shapes of light pulses emitted by
the lamp, such as, for example, squaring or smoothing of sub-pulses
of non-coherent pulsed light, equalizing the sub-pulses, and
delivering the energy over an extended period of time, according to
a selected pulse shape or sub-pulse related to target
specifications. The current control may enable changing of a pulse
spectrum, during a pulse, to comply with target specifications.
These developments may enable administration of customizable
non-coherent pulsed light treatments, enabling enhanced safety and
efficacy of such treatments. Sub-pulses, as described herein, may
relate to pulses and/or portions of pulses that may be initiated,
generated, delivered etc., according to some embodiments of the
present invention. Pulses, as described and/or as claimed herein,
may relate to whole pulses, partial pulses, sub-pulses or other
suitable portions of pulses. For example, the length of a pulse
and/or the combined lengths of one or more sub-pulses within a
pulse may be between 1 ms to several seconds.
[0016] Reference is now made to FIG. 1A, which is a schematic
illustration of a system 100 enabled to control non-coherent pulsed
light applications, such as, for example, intensed Pulse Light.TM.
(IPL.TM.) based skin treatments. As can be seen in FIG. 1, system
100 may include a power supply 105, which may include, for example,
an electric power source, e.g., a battery or any other suitable
source of electric power. A current source, for example a capacitor
110, may be provided to store a charge, and may be subsequently
periodically discharged to generate current, which may be used to
operate a lamp 135 producing non-coherent light energy in a pulsed
mode. Power supply 105 may be connected to lamp 135 directly or via
a current regulator and/or modulator 115, as described below. Lamp
135 may be operated in a pulsed mode, and may provide, for example,
non-coherent pulsed light to one or more targets. Lamp 135 may
include, for example, a xenon, krypton or any other light source
that may generate a wide wavelength spectrum of light energy
output. For example, an exemplary lamp 135 may provide light energy
with wavelengths ranging between 300-1100 nanometers. Lamp 135 may
be associated with at least one light sensor unit 130, to sense,
for example, light intensity and/or light wavelengths in a vicinity
of lamp 135. Light sensor unit 130 may be independent of lamp 135,
or integrated into lamp 135. In other embodiments light sensor unit
130 may sense, for example, light intensity and/or light
wavelengths reflected from a treatment area, for example, a body
surface.
[0017] Current regulator and/or modulator 115 may be used to
modulate energy flow (e.g., electric pulses) between power supply
105 and lamp 135 and/or between capacitor 110 and lamp 135. Current
regulator/modulator 115 may include a controller unit 120, and a
switching module 125. Controller unit 120 may be independent of
current regulator 115 (as shown in FIG. 1), and/or in other
embodiments may be included within current regulator 115 or within
other suitable system components. Switching module 125 may be
adapted to modulate the power supply or current provided to lamp
135, to effect changes in spectral distribution and/or light
intensity emitted from lamp 135. Controller unit 120 may include a
data storage unit (not shown), which may store executable code,
non-coherent pulsed light data, treatment data, user data, and/or
other relevant data. For example, pulse parameters for a treatment
(including shape, energy, spectrum during different portions of
pulse, etc.) may be prepared, according to the resolution of
optical parameters between a target and the surrounding tissue.
Such parameters may be stored in controller unit 120. Controller
120 may translate the pulse parameters to system parameters, such
as capacitor voltage, lamp current etc., possibly using suitable
software.
[0018] Controller 120 may be adapted to process illumination data
received from light sensor 130. Results of the processing of data
from light sensor 130 by controller 120 may be used to instruct
switching module 125 to activate lamp 135 with a controlled current
pattern. For example, switching module 125 may provide an
appropriate current pattern to generate a temporal distribution of
light, and a selected wavelength spectrum of light energy during a
pulse from lamp 135. Controller 120 may, for example, determine the
wavelength spectrum to be generated, thereby enabling spectrum
switching during a pulse and/or during a sub-pulse, as described
below with reference to FIGS. 4A-4C. Switching module 125 may
include a current control module, to control the magnitude of
current supplied to lamp 135. Such current control may affect the
spectrum emitted by lamp.
[0019] A light conducting material 145, such as a light guide, gel
or any combination thereof, or any other suitable material, may be
placed on a body surface 150, to enable energy emitted by lamp 135
to flow efficiently to body surface 150. In some embodiments,
efficient energy flow may be achieved by connecting current
regulator 115 or modulator 125 directly to power supply 105, e.g.,
not via capacitor 110. In some embodiments, efficient energy flow
and/or control over current delivered to lamp 135 may be achieved
by using filters, for example, changeable or variable filters 140.
Filters 140, however, may be changed according to a pre-determined
plan, without feedback. According to one embodiment of the present
invention, results of the processing of data from light sensor 130
by controller 120 may be used to control operation of filters, for
example, to change pulse wavelengths within a pulse. Filters 140
may include, for example, cut on filters, cut off filters, band
pass filters, neutral density filters, and/or any other suitable
filters having one or more different light spectrum and/or light
intensity capabilities.
[0020] In other embodiments, as can be seen with reference to FIG.
1B, system 100 may be provided with energy by a current supply 117,
which may supply current at selected durations, intensities, or
other selected criteria.
[0021] FIG. 2 schematically illustrates a method of controlling
non-coherent pulsed light. As can be seen in FIG. 2, at block 200 a
treatment plan may be prepared, for example, using a processing
unit associated with treatment software. For example, treatment
software may enable preparation of treatment pulse parameters, such
as shape, energy, and spectrum etc., during the different portions
of a pulse and/or a sub-pulse, according to optical and/or
biological properties of a target and/or of surrounding tissue. At
block 205 the pre-defined pulse parameters may be translated into
system parameters, such as capacitor voltage, lamp current etc.,
for example by a processing unit associated with treatment
software. At block 210 a pulse may be initiated, for example, using
a power supply to a charge capacitor to generate one or more
pulses, to activate a lamp. Current may be supplied directly to the
lamp from the power supply, for example, not via the capacitor. At
block 215 system 100 may determine whether or not to operate with
sensor feedback, for example using a controller.
[0022] Pulse(s) may be operated in a plurality of modes, or in any
combination of modes. In a first mode, indicated by block 220, the
method may be implemented using sensor feedback ("YES" at block
215). The light output that may be sensed by a sensor, for example,
a light sensor, may be received and processed by the controller.
The light sensor may sense parameters such as light intensity,
light wavelengths etc. Other sensors, for example current sensors
or tissue temperature sensors etc. may also be used. At block 220,
the controller may process signals from the sensor, to determine if
the light output complies with predetermined pulse parameters
and/or biological characteristics. At block 220, if the
predetermined pulse parameters are being met ("YES" at block 220),
a current regulator may enable a continued generation of pulses
and/or sub-pulses according to the initial predetermined treatment
pulse parameters, at block 230. At block 225, if the predetermined
pulse parameters are not being met ("NO" at block 220), the
controller may control the lamp current and/or light output,
thereby determining the lamp output during a pulse. In this way,
the adjusting of electrical input parameters may enable compliance
of a pulse and/or a sub-pulse to predetermined pulse parameters
and/or biological characteristics. For example, a switching module
may increase or decrease the current to the lamp, optionally during
a pulse, to increase, decrease, or maintain the light output from
the lamp at selected levels. For example, changing the current
during a pulse and/or during a sub-pulse may enable spectrum
shifting of light emitted by the lamp during a pulse and/or during
a sub-pulse, and/or changing of temporal distribution of light
emitted by the lamp during a pulse and/or during a sub-pulse.
[0023] In a second mode, indicated by block 230, the method may be
implemented without using sensor feedback ("NO" at block 215),
according to the predetermined treatment plan. At block 240, the
controller may determine whether or not to end the pulse. At block
250, if the controller determines to end the pulse ("YES" at block
240), pulse generation may be stopped. At block 260, if the
controller determines to continue the pulse ("NO" at block 240),
controller may determine whether or not future portions of a pulse
require changing of filters. At block 270, if the controller
determines to operate with changeable filters ("YES" at block 260),
filters may be changed at pre-determined time intervals during a
pulse. At block 270, the method may continue from block 215, where
a decision whether to operate a subsequent pulse portion with or
without feedback may be determined. At block 260, if the controller
determines to operate without changeable filters ("NO" at block
260), the method may continue from block 215, where a decision
whether to operate a subsequent pulse portion with or without
feedback may be determined. For example, a spectral filter, such as
a cut on, cut off, band pass or other filter, may be used with the
lamp at a constant current. For example, a neutral density filter
may be used to control the temporal shape of the pulse and/or a
sub-pulse, during the pulse, without making spectral changes. Any
combination of some or all of the above functions, as well as
additional suitable functions, may be implemented.
[0024] In this way, the pulse shape representing the light output
from the lamp may be controlled to comply with target
specifications. For example, if the light intensity is too high, or
the spectrum being illuminated by the lamp is out of the required
spectrum limits for a target being treated, the regulator may
control the energy supplied to the lamp during a pulse to generate
the required light output, for example, according to a selected
spectrum, a selected pulse length, and/or a duty cycle. Carefully
tuned pulses and/or sub-pulses may produce considerable temperature
rises at the target, while maintaining temperatures in adjacent
tissues well below a selected safety threshold. For example,
changing the spectral distribution may enable outputting a
significant quantity of light energy in a yellow light range, for
example, by increasing the current. In addition, for example, the
current may be lowered and a short (e.g. 500 nm) cut-off filter may
be used, thereby maintaining most of the light in the safer IR
region of the spectrum. Later during the pulse, the current may be
increased to enable shifting of the spectrum towards the yellow
visible light range.
[0025] According to an embodiment of the present invention, target
tissue parameters may be measured during a pulse, and pulses or
sub-pulses may be adjusted during the pulse to optimize the
treatment. Both spectrum distribution and time dependence of pulse
amplitudes may be varied according to the type, position, and
dimensions of a selected target, or modifications of target
parameters during treatment. Such operations may enable optimal
light energy to be applied to selected targets, providing
relatively efficient and safe usage of light energy to treat target
locations.
[0026] According to some embodiments of the present invention, at
least one physical property may be defined that differentiates
between one or more targets and surrounding tissue, to enable
increasing the targeted effect of treatment, while preserving the
surrounding tissue. For example, altering the resolution of optical
parameters between a target and the surrounding tissue may enable
differentiation of targets located in dark skin types, targets
having physical properties similar to or only slightly different
from--surrounding tissue, targets located deep in the dermis,
and/or combinations of the above. Such differentiation may enable,
for example, increased safety and/or efficacy when applying
treatments including hair removal, blood vessel treatments,
textural lesion treatments etc.
[0027] Reference is now made to FIGS. 3A-3E, which schematically
illustrate light energy outputs, according to some embodiments of
the present invention. As can be seen with reference to FIG. 3A,
traditional non-coherent pulsed light pulse shapes or sub-pulse
shapes, such as pulses 31 and 32, may be characterized by an energy
peak at the beginning of the pulse, or sub-pulse, followed by a
rapid decline in the energy delivered to a target. Such energy
output patterns may generally result from insufficient control of
the discharge from a capacitor 110. Energy supplied above an
optimal level 33, represented by area 34, may be, for example,
dangerous and/or unusable energy. Energy levels below optimal level
33, represented by area 35, may relate to energy deficiencies as a
result of outputs from a capacitor that are too low to impact
effectively on a target.
[0028] FIGS. 3B-3E, for example, illustrate various examples of
pulse shapes that may be provided by a light source producing
non-coherent pulsed light, such as lamp 135, according to some
embodiments of the present invention. As described above,
controller 120, in association with capacitor 110, current
regulator 115, and/or switching module 125 may provide pulses of
energy that may be controlled, for example to produce pulses and/or
sub-pulses of selected durations, intensities etc. In FIG. 3B, for
example, the sub-pulses 31, 32 have been squared or smoothed to
optimal level 33, according to selected values, thereby equalizing
the energy emitted by the sub-pulses. FIG. 3C illustrates an
example of an extended pulse, which may be a relatively long and
relatively low power pulse. For example, relatively long square
pulses may enable lamp 135 to operate at a low current (e.g., with
a low plasma temperature), which may lead to spectral distribution
with, for example, a maximum wavelength of between 800 and 1000 nm.
Such a shift of the non-coherent pulsed light output may be used to
provide relatively high safety levels for non-coherent pulsed light
treatments. For example, treatments for darker skinned people may
require relatively longer exposure, by giving fluence over an
extended period of time. Such a system may therefore enable
relatively safer treatment of dark skinned people, though possibly
at a lower efficacy yield. As can be seen in FIGS. 3B-3C, electric
energy supplied to the lamp may be controlled to provide a selected
light intensity, represented by line 33.
[0029] According to some embodiments of the present invention, a
multiple stage non-coherent pulsed light treatment may be provided.
For example, a light output from a lamp may be used to enable
pre-heating of a target. The light output, for example, according
to the pulse length or spectrum, may be adapted to enable
implementation of a selected treatment at the target. Examples of
multi-stage treatments may be seen with reference to FIGS. 3D-3E.
FIG. 3D illustrates an example of a relatively long, low power,
pre-heating IR shifted pulse followed by a high impact pulse (e.g.,
towards green/yellow wave length).
[0030] FIG. 3E illustrates an exemplary customized controlled
pulse. Such a pulse, as can be seen in FIG. 3E, may provide
improved safety and efficiency, as it may be, tailored or
customized according to target and skin type, or any other factors.
For example, a non-specific heating of tissue, from the deeper to
the more superficial zones, together with a chilling procedure that
may further cool the epidermis during the non-coherent pulsed light
procedure, may be administered. Of course, other pulse types and
dimensions may be used. Any number of stages, or combinations of
stages, may be used.
[0031] In some embodiments the preheating pulse may be, for
example, be used to implement non-specific heating of one or more
targets and surrounding tissue. Preheating may utilize, for
example, pulses in the red-infrared range. A subsequent treatment
pulse or sub-pulse may be utilized. Such a treatment pulse may be,
for example, in the yellow-blue spectrum range (e.g., 400-600 nm).
Other suitable ranges may be used.
[0032] In the case of treatments using changes in spectral
distribution, the length of the pulse or of the total sub-pulses
may be, for example, between 1 ms up to 1 sec. The change of the
related spectral distribution may be, for example, between 300 and
1,500 nm. The controlled change of spectral distribution may be
implemented by precisely controlling the current provided to the
lamp, and/or by using flying or changing filters.
[0033] In the case of treatments using changes in light
intensities, the length of the pulse or of the total sub-pulses may
be, for example, between 1 ms up to 1 sec. The current provided to
the lamp may be, for example, between 10 and 600 Amps. In some
embodiments the current density may be, for example, between
100-4000 Amps/cm2, or the plasma temperature may be, for example,
between 1,000 to 12,000.degree. K.
[0034] According to some embodiments of the present invention,
treatments with multiple modes of operation within a pulse may
enable differentiation between one or more targets and surrounding
tissue. Such treatments may help improve the safety and/or efficacy
of treatments of targets located in dark skin types, of targets
having physical properties similar to or only slightly different
from surrounding tissue, of targets located deep in the dermis,
and/or any combinations of the above treatments. Furthermore,
treatment for hair removal, blood vessel modification, textural
lesions and/or other procedures may be aided using treatments with
multiple modes of operation within a pulse, as described above.
[0035] Reference is now made to FIGS. 4A-4C, which are graphs
illustrating examples of spectral distribution of light output from
a light source producing non-coherent pulsed light, such as lamp
135, for different current input (in Amperes), for example,
delivered from power supply 105 or capacitor 110 to lamp 135. As
can be seen in FIG. 4A, when providing a pulse of 350 Amperes (A),
for example, the resulting output from lamp 135 may provide a
certain spectrum and light intensity. When providing a pulse of 200
A, for example, as can be seen in FIG. 4B, the resulting output
from lamp 135 may provide a shift in spectrum and light intensity.
When providing a pulse of 100 A, for example, as can be seen in
FIG. 4C, the resulting output from lamp 135 may provide further
shift of the spectrum and light intensity. Generally, FIGS. 4A-4C
show a shift in the spectrum towards the infrared wavelengths,
resulting from the change (reduction) of current supplied to the
lamp and/or the change of intensity. These phenomena may be formed
during pulses, using methods and devices of the present
invention.
[0036] According to some embodiments of the present invention,
regulator 125 may enable modulation of the output to lamp 135, such
that a selected output may be provided to lamp 135. This selected
output, according to an embodiment of the present invention, may
be, for example, a suitable mixture or combination of the current
inputs described with reference to FIGS. 4A-4C, or other current
inputs. A controlled current input as described above may enable
emission of light energy according to the requirements of one or
more selected targets. For example, the output may be controlled to
yield a relatively constant light intensity, a predetermined
spectrum, selected pulse duration or sub-pulse duration, a desired
duty cycle, a combination of pulses, and/or other selected pulse
parameters. The ability to change a spectrum of outputted light
energy may be referred to as spectrum switching, which, according
to some embodiments of the present invention, may be implemented
within a pulse.
[0037] According to some embodiments of the present invention,
two-part pulses, for example, may be used to control light output
for a given treatment, for example, for wrinkle reduction. For
example, in a first operation a low power, long duration, pulse may
be generated for preheating at a low plasma temperature (e.g. using
light in the infrared spectrum). During this operation the tissue
may be heated to just below a damage threshold, for example, in a
non-selective way, to a depth of up to approximately 2 mm.
Simultaneously, cooling, for example contact cooling, may be
applied to decrease the temperature of a treatment area, for
example the epidermis. In a second stage, a relatively short,
higher power, pulse may be generated. The plasma temperature during
the second stage may be chosen, for example, to match the
absorption of hemoglobin. In such a case, the temperature around
small capillaries may increase to a level, where, for example,
collagen re-generation may occur, which may lead to skin
rejuvenation.
[0038] According to some embodiments of the present invention,
two-part or multi-part pulses, as described above, may be used to
control light output for, for example, effective treatment of
medium size blood vessels. For example, a first sub-pulse may be
generated with high power for a short duration, with most of the
light in the green-yellow spectral region. This sub-pulse may
initiate, for example, a red shift of blood absorption. A second
sub-pulse that is tuned to emit infrared light may be generated,
which may be less dangerous to the epidermis.
[0039] According to some embodiments of the present invention,
mechanical filters may be changed during a pulse, in addition to
current change, or in any combination. The usage of filters may
refer to changeable filters, flying filters, or other suitable
filters that may have different light spectrum filtering
characteristics and/or different light intensifying
characteristics, to enable control of non-coherent pulsed light
during a pulse. The mechanism for controlling the changeable
filters may be similar to a mechanical camera shutter. Such filters
may be used with or without a switching module 125 to change the
pulse shape emitted from lamp 135, during a pulse. For example, a
spectral filter, such as a cut on, cut off, band pass or other
filter, may be used with lamp 135 operated at a constant current,
to change the spectrum emitted during a pulse. For example, a
neutral density filter may be used to control the temporal shape of
the pulse without making spectral changes.
[0040] The foregoing description of the embodiments of the
invention has been presented for the purposes of illustration and
description. It is not intended to be exhaustive or to limit the
invention to the precise form disclosed. It should be appreciated
by persons skilled in the art that many modifications, variations,
substitutions, changes, and equivalents are possible in light of
the above teaching. It is, therefore, to be understood that the
appended claims are intended to cover all such modifications and
changes as fall within the true spirit of the invention.
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