U.S. patent application number 10/542390 was filed with the patent office on 2006-07-13 for method and apparatus for dermatological treatment and fractional skin resurfacing.
Invention is credited to Richard Anderson, Dieter Manstein.
Application Number | 20060155266 10/542390 |
Document ID | / |
Family ID | 33131823 |
Filed Date | 2006-07-13 |
United States Patent
Application |
20060155266 |
Kind Code |
A1 |
Manstein; Dieter ; et
al. |
July 13, 2006 |
Method and apparatus for dermatological treatment and fractional
skin resurfacing
Abstract
A system and method for performing fractional resurfacing of a
target area of skin using electromagnetic radiation are provided.
An electromagnetic radiation is generated by an electromagnetic
radiation source. The electromagnetic radiation is caused to be
applied to a particular portion of a target area of skin. The
electromagnetic radiation can be impeded from affecting another
portion of the target area of the skin by a mask. Alternatively,
the electromagnetic radiation may be applied to portions of the
target area of the skin, other than the particular portion.
Inventors: |
Manstein; Dieter; (Boston,
MA) ; Anderson; Richard; (Lexington, MA) |
Correspondence
Address: |
DORSEY & WHITNEY LLP;INTELLECTUAL PROPERTY DEPARTMENT
250 PARK AVENUE
NEW YORK
NY
10177
US
|
Family ID: |
33131823 |
Appl. No.: |
10/542390 |
Filed: |
March 25, 2004 |
PCT Filed: |
March 25, 2004 |
PCT NO: |
PCT/US04/09452 |
371 Date: |
July 13, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60458770 |
Mar 27, 2003 |
|
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|
Current U.S.
Class: |
606/17 ; 606/13;
606/3; 606/9 |
Current CPC
Class: |
A61B 2090/0454 20160201;
A61N 2005/0665 20130101; A61B 18/203 20130101; A61B 2018/208
20130101; A61B 2090/049 20160201; A61B 2018/00577 20130101; A61B
2017/00765 20130101; A61B 2018/00452 20130101; A61B 2018/20351
20170501; A61B 2018/00023 20130101; A61B 2018/205545 20170501; A61B
2018/2065 20130101; A61B 2018/0047 20130101; A61N 5/0616 20130101;
A61B 2090/0436 20160201; A61B 2018/00005 20130101 |
Class at
Publication: |
606/017 ;
606/009; 606/003; 606/013 |
International
Class: |
A61B 18/18 20060101
A61B018/18 |
Claims
1. An apparatus, comprising: at least one member configured to mask
at least one portion of a target area of skin from an
electromagnetic radiation provided by an electromagnetic radiation
source, wherein at least one member is configured such that a
particular amount of the electromagnetic radiation that impacts the
at least one member is reflected in a direction of the
electromagnetic radiation source.
2. The apparatus of claim 1, wherein the target area is a
predetermined area of the skin.
3. The apparatus of claim 1, wherein each of the at least one
shielding member is configured to reflect the impacted
electromagnetic radiation away from the apparatus.
4. The apparatus of claim 1, wherein each of the at least one
shielding member is configured to absorb a minimal amount of
electromagnetic radiation.
5. The apparatus of claim 1, wherein the electromagnetic radiation
is optical radiation.
6. The apparatus of claim 1, wherein the electromagnetic radiation
source is an ablative laser.
7. The apparatus of claim 1, wherein the electromagnetic radiation
source is generated by a carbon dioxide laser.
8. The filtering apparatus of claim 1, wherein the electromagnetic
radiation source is an Er:YAG laser.
9. The apparatus of claim 1, wherein the at least one shielding
member masks at least 0.1% of the target area from the
electromagnetic radiation.
10. The apparatus of claim 1, wherein the at least one member masks
at most 90% of the target area from the electromagnetic
radiation.
11. The apparatus of claim 1, wherein the at least one member masks
the at least one portion of the target area such that the
electromagnetic radiation is prevented from affecting the at least
one portion of the target area.
12. The apparatus of claim 1, wherein the at least one member is at
least 50 pm in width and at most 300 .mu.m.
13. The apparatus of claim 19 wherein the at least one member is
configured to define at least one aperture.
14. The apparatus of claim 13, wherein the at least one aperture
has a width of at least 50 .mu.m and at most 1000 .mu.m.
15. The apparatus of claim 1, wherein the at least one member is
cooled.
16. The apparatus of claim 1, wherein the at least one member is
adapted to be cooled to at least 37.degree. C. and at most negative
20.degree. C.
17. The apparatus of claim 1, wherein the at least one member
includes at least one channel extending therethrough.
18. The apparatus of claim 17, wherein the at least one channel is
configured to facilitate a cooling agent.
19. A method for treating dermatological conditions, comprising:
controlling an electromagnetic radiation source to generate an
electromagnetic radiation; causing the electromagnetic radiation to
be applied to a target area of skin; and masking at least one
portion of the target area of the skin from the electromagnetic
radiation.
20. The method of claim 19, wherein the masking step is performed
using a mask which includes at least one member.
21. The method of claim 20, wherein the at least one shielding
member masks at least 0.1% of the target area from the
electromagnetic radiation.
22. The method of claim 20, wherein the at least one member masks
at most 90% of the target area from the electromagnetic
radiation.
23. The method of claim 20, wherein the at least one member masks
the at least one portion of the target area such that the
electromagnetic radiation is prevented from affecting the at least
one portion of the target area.
24. The method of claim 20, wherein the at least one member masks
the at least one portion of the target area such that the
electromagnetic radiation has an affect on the at least one portion
than an affect to other portions of the target area.
25. The method of claim 20, wherein the at least one member is at
least 50 .mu.m in width and at most 300 .mu.m.
26. The method of claim 20, wherein the at least one member is
configured to define at least one aperture.
27. The method of claim 26, wherein the at least one aperture has a
width of at least 50 .mu.m and at most 1000 .mu.m.
28. The method of claim 20, wherein the at least one member is
cooled.
29. The method of claim 20, wherein the at least one member is
adapted to be cooled to at least 37.degree. C. and at most negative
20.degree. C.
30. The method of claim 20, wherein the at least one member
includes at least one channel extending therethrough.
31. The method of claim 30, wherein the at least one channel is
configured to facilitate a cooling agent.
32. The method of claim 19, wherein the mask is configured to
reflect a predetermined amount of the electromagnetic radiation in
a direction of the electromagnetic radiation source.
33. The method of claim 19, wherein the mask is configured to
reflect the electromagnetic radiation away from the electromagnetic
radiation source.
34. The method of claim 19, wherein the mask is configured to
diffuse the electromagnetic radiation.
35. The method of claim 19, wherein the electromagnetic radiation
has a particular wavelength.
36. The method of claim 35, wherein a surface of the mask has a
microstructure having a periodicity approximately in the range of
the particular wavelength.
37. The method of claim 19, wherein the mask is configured to
absorb a predetermined amount of the electromagnetic radiation.
38. The method of claim 19, wherein the electromagnetic radiation
source is an ablative laser.
39. The method of claim 19, wherein the electromagnetic radiation
source is a carbon dioxide laser.
40. The method of claim 19, wherein the electromagnetic radiation
source is a Er:YAG laser.
41. The method of claim 19, further comprising the steps of:
controlling a further electromagnetic radiation source to generate
a further electromagnetic radiation; and applying the further
electromagnetic radiation to the target area of the skin.
42. The method of claim 41, wherein the further electromagnetic
radiation source is substantially the same as the electromagnetic
radiation source.
43. The method of claim 41, wherein the further electromagnetic
radiation source is different than the electromagnetic radiation
source.
44. The method of claim 41, wherein the further electromagnetic
radiation source is one of a Q-switched ruby laser, a Nd:YAG laser,
a KTP laser and an Alexandrite laser.
45. The method of claim 19, further comprising the step of
introducing a substance to the target area, wherein the substance
is one of growth factors, collagen byproducts, collagen precursors,
hyaluronic acid, vitamins, antioxidants, amino acids and
supplemental minerals.
46. An apparatus for treating dermatological conditions,
comprising: a delivery module configured to direct an
electromagnetic radiation generated by an electromagnetic radiation
source to a target area of skin; and a mask including at least one
member configured to mask at least one portion of the target area
of the skin from the electromagnetic radiation.
47. The apparatus of claim 46, wherein the at least one member is
configured to reflect a predetermined amount of the electromagnetic
radiation in the direction of the electromagnetic radiation
source.
48. The apparatus of claim 46, wherein each of the at least one
member is configured to reflect the electromagnetic radiation away
from the electromagnetic radiation source.
49. The apparatus of claim 46, wherein each of the at least one
member is configured to diffuse the electromagnetic radiation.
50. The apparatus of claim 46, wherien the electromagnetic
radiation has a particular wavelength.
51. The apparatus of claim 50, wherein each of the at least one
member includes a microstructure having a periodicity in the range
of the particular wavelength.
52. The apparatus of claim 46, wherein each of the at least one
member is configured to absorb a mimimal amount of the
electromagnetic radiation.
53. The apparatus of claim 46, wherein the electromagnetic
radiation source is an ablative laser.
54. The apparatus of claim 46, wherein the electromagnetic
radiation source is a carbon dioxide laser.
55. The apparatus of claim 46, wherein the electromagnetic
radiation source is a Er:YAG laser.
56. The apparatus of claim 46, wherein the at least one shielding
member masks at least 0.1% of the target area from the
electromagnetic radiation.
57. The apparatus of claim 46, wherein the at least one member
masks at most 90% of the target area from the electromagnetic
radiation.
58. The apparatus of claim 46, wherein the at least one member
masks the at least one portion of the target area such that the
electromagnetic radiation is prevented from affecting the at least
one portion of the target area.
59. The apparatus of claim 46, wherein the at least one member
masks the at least one portion of the target area such that the
electromagnetic radiation is prevented from affecting the at least
one portion of the target area.
60. The apparatus of claim 46, further comprising a case having an
aperture formed in a sidewall of the case, wherein the case
contains the electromagnetic radiation source and the delivery
module, and wherein the at least one member is in registration with
the aperture.
61. The apparatus of claim 46, wherein the delivery module includes
a beam collimator.
62. The apparatus of claim 46, wherein the delivery module includes
optical components.
63. An apparatus for treating dermatological conditions,
comprising: a delivery module configured to direct electromagnetic
radiation generated by an electromagnetic radiation source to a
predetermined area within a target area of skin, wherein the
predetermined area is located in a location relative to the
delivery module, and wherein the electromagnetic radiation is
adapted to cause thermal damage to epidermal tissue and dermal
tissue of the predetermined area within the target area of the
skin; and a translator capable of moving the delivery module, such
that the delivery module targets a plurality of spatially separated
individual exposure areas of the predetermined area.
64. The apparatus of claim 63, wherein the electromagnetic
radiation source is an ablative laser.
65. The apparatus of claim 63, wherein the electromagnetic
radiation source is one of a diode laser, a fiber laser, a solid
state laser and a gas laser.
66. The apparatus of claim 63, further comprising a case having an
aperture formed in a sidewall of the case, wherein the case
contains the electromagnetic radiation source, the delivery module
and the translator.
67. The apparatus of claim 66, further comprising a transparent
plate in registration with the aperture, wherein the transparent
plate seals the case.
68. The apparatus of claim 67, wherien the electromagnetic
radiation has a particular wavelength.
69. The apparatus of claim 68, wherein the transparent plate
absorbs a predetermined amount of the electromagnetic radiation at
the particular wavelength.
70. The apparatus of claim 67, wherein the transparent plate is
cooled to provide an aesthetic affect to the target area of the
skin.
71. The apparatus of claim 67, wherein the transparent plate is
configured to be cooled to at least 37.degree. C. and at most
negative 20.degree. C.
72. The apparatus of claim 63, wherein the delivery module includes
a beam collimator.
73. The apparatus of claim 63, wherein the delivery module includes
optical components.
74. The apparatus of claim 63, wherein the dermal tissue of the
skin of the plurality of spatially separated individual exposure
areas is damaged down to a predetermined depth thereof.
75. The apparatus of claim 63, wherein the plurality of spatially
separated individual exposure areas cover at least five percent of
the target area and at most sixty percent of the target area.
76. The apparatus of claim 63, wherein an average distance between
each of the plurality of spatially separated individual exposure
areas is at least 10 .mu.m and at most 2000 .mu.m.
77. The apparatus of claim 639 wherein each of the plurality of
spatially separated individual exposure areas have a diameter of
approximately 0.1 mm.
79. The apparatus of claim 63, wherein each of the plurality of
spatially separated individual exposure areas have a lateral
diameter of a smallest dimension of at least 1 .mu.m and at most
500 .mu.m.
79. The apparatus of claim 63, further comprising an optically
transparent plate disposed between delivery module and the target
area of the skin.
80. The apparatus of claim 79, wherein the optically transparent
plate is cooled.
81. The apparatus of claim 79, wherein the optically transparent
plate cooled to at least 37.degree. C. and at most negative
20.degree. C.
82. The apparatus of claim 63, wherein a first one of the plurality
of spatially separated individual exposure areas is separated from
a second one of the plurality of spatially separated individual
exposure areas.
83. The apparatus of claim 82, wherein the first one of the
plurality of spatially separated individual exposure areas is
separated from the second one of the plurality of spatially
separated individual exposure areas by non-irradiated skin
section.
84. The apparatus of claim 63, wherein a first one of the plurality
of spatially separated individual exposure areas is exposed to
electromagnetic radiation associated with a first set of parameters
and a second one of the plurality of spatially separated individual
exposure areas is exposed to electromagnetic radiation associated
with a second set of parameters.
85. The apparatus of claim 63, wherein at least two of the
individual exposure areas are separated from one another by an
unaffected area.
86. The apparatus of claim 85, wherein the at least two of the
individual exposure areas are separated from one another by at
least approximately 125 .mu.m.
87. The apparatus of claim 85, wherein the at least two of the
individual exposure areas are separated from one another by at most
approximately 500 .mu.m.
88. The apparatus of claim 63, wherein one of at least one hundred
of the individual exposure areas within an area of a square
centimeter is separated from another one of the at least one
hundred of the individual exposure areas by an unaffected area.
89. The apparatus of claim 63, wherein one of at least one thousand
of the individual exposure areas within an area of a square
centimeter is separated from another one of the at least one
thousand of the individual exposure areas by an unaffected
area.
90. A method for treating dermatological conditions, comprising the
steps of: (a) controlling an electromagnetic radiation source to
generate first and second electromagnetic radiation; (b) causing a
first electromagnetic radiation to be applied to a first individual
exposure area of a plurality of spatially separated individual
exposure areas of a target area of skin, wherein epidermal tissue
and dermal tissue of the first individual exposure area are
thermally damaged; and (c) causing a second electromagnetic
radiation to be applied to a second individual exposure area of a
plurality of spatially separated individual exposure areas of the
target area of the skin, wherein epidermal tissue and dermal tissue
of the second individual exposure area are thermally damaged,
wherein the first electromagnetic radiation is one of the same as
and different from the second electromagnetic radiation, and
wherein the first and second individual exposure areas are
separated from one another by an unaffected area.
91. The method of claim 90, wherein the target area has a surface
area of approximately 1 cm.sup.2.
92. The method of claim 90, wherein the electromagnetic radiation
source is an ablative laser.
93. The method of claim 90, wherein the electromagnetic radiation
source is one of a diode laser, a fiber laser, a solid state laser
and a gas laser.
94. The method of claim 90, wherein the dermal tissue of the skin
of the plurality of spatially separated individual exposure areas
is damaged down to a predetermined depth thereof.
95. The method of claim 90, wherein the plurality of spatially
separated individual exposure areas cover at least twenty percent
of the target area and at most forty percent of the target
area.
96. The method of claim 90, wherein an average distance between
each of the plurality of spatially separated individual exposure
areas is at least approximately 10 um and at most approximately
2000 .mu.m.
97. The method of claim 90, wherein each of the plurality of
spatially separated individual exposure areas have a diameter of
approximately 0.1 mm.
98. The method of claim 90, wherein each of the plurality of
spatially separated individual exposure areas have a lateral
diameter of a smallest dimension of at least approximately 1 .mu.m
and at most approximately 500 .mu.m.
99. The method of claim 90, further comprising the step of: (d)
placing an optically transparent plate in registration with the
target area.
100. The method of claim 99, wherein the optically transparent
plate is cooled.
101. The method of claim 99, wherein the optically transparent
plate cooled to at least approximately 37.degree. C. and at most
approximately negative 20.degree. C.
102. The method of claim 90, wherein the first individual exposure
area is separated from a second individual exposure area.
103. The method of claim 90, wherein the first individual exposure
area is separated from the second individual exposure area by
non-irradiated skin.
104. The method of claim 90, wherein the first electromagnetic
radiation is associated with a first set of parameters, and wherein
the second electromagnetic radiation is associated with a second
set of parameters.
105. The method of claim 90, wherein at least two of the individual
exposure areas are separated from one another by an unaffected
area.
106. The method of claim 105, wherein the at least two of the
individual exposure areas are separated from one another by at
least approximately 125 .mu.m.
107. The method of claim 105, wherein the at least two of the
individual exposure areas are separated from one another by at most
approximately 500 .mu.m.
108. The method of claim 90, wherein one of at least one hundred of
the individual exposure areas within an area of a square centimeter
is separated from another one of the at least one hundred of the
individual exposure areas by an unaffected area.
109. The method of claim 90, wherein one of at least one thousand
of the individual exposure areas within an area of a square
centimeter is separated from another one of the at least one
thousand of the individual exposure areas by an unaffected
area.
110. An apparatus for treating dermatological conditions,
comprising: a first arrangement capable of providing at least one
electro-magnetic radiation which is configured to be usable on a
target area of an anatomical structure; and a second arrangement
capable of directing at least one first radiation of the at least
one electromagnetic radiation to a first location of the target
area, and at least one second radiation of the at least one
electromagnetic radiation to a second location of the target area,
wherein the first and second locations are provided at a distance
from one another of approximately between at least 10 .mu.m and at
most 2 mm.
111. The apparatus according to claim 110, further comprising: a
third arrangement which is capable of assisting in obtaining a
relative velocity information between the target area and the first
arrangement, wherein the velocity information is usable by the
second arrangement.
112. The apparatus according to claim 110, wherein the second
arrangement is further capable of separating the electromagnetic
radiation into the at least one first radiation and the at least
one second radiation.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority from U.S.
Provisional Patent Application Ser. No. 60/458,770 filed Mar. 27,
2003, the entire disclosure of which is incorporated herein by
reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field Of The Invention
[0003] The present invention relates to methods and apparatus that
use electromagnetic radiation for dermatological treatment and,
more particularly to a method and apparatus that use optical
radiation to ablate or damage a target area of skin surface for
dermatological treatment, which skin surface includes the epidermis
and parts of the dermis as the objective or side effect of the
desired treatment.
[0004] 2. Background Art
[0005] There is an increasing demand for repair of or improvement
to skin defects, which can be induced by aging, sun exposure,
dermatological diseases, traumatic effects, and the like. Many
treatments which use electromagnetic radiation have been used to
improve skin defects by inducing a thermal injury to the skin,
which results in a complex wound healing response of the skin. This
leads to a biological repair of the injured skin.
[0006] Various techniques providing this objective have been
introduced in recent years. The different techniques can be
generally categorized in two groups of treatment modalities:
ablative laser skin resurfacing ("LSR") and non-ablative collagen
remodeling ("NCR"). The first group of treatment modalities, i.e.,
LSR, includes causing thermal damage to the epidermis and/or
dermis, while the second group, i.e., NCR, is designed to spare
thermal damage of the epidermis.
[0007] LSR with pulsed CO.sub.2 or Er:YAG lasers, which may be
referred to in the art as laser resurfacing or ablative
resurfacing, is considered to be an effective treatment option for
signs of photo aged skin, chronically aged skin, scars, superficial
pigmented lesions, stretch marks, and superficial skin lesions.
However, patients may experience major drawbacks after each LSR
treatment, including edema, oozing, and burning discomfort during
first fourteen (14) days after treatment. These major drawbacks can
be unacceptable for many patients. A further problem with LSR
procedures is that the procedures are relatively painful and
therefore generally require an application of a significant amount
of analgesia While LSR of relatively small areas can be performed
under local anesthesia provided by injection of an anestheticum,
LSR of relatively large areas is frequently performed under general
anesthesia or after nerve blockade by multiple injections of
anesthetic.
[0008] Any LSR treatment results in thermal skin damage to the
treatment area of the skin surface, including the epidermis and/or
the dermis. LSR treatment with pulsed CO.sub.2 lasers is
particularly aggressive, causing thermal skin damage to the
epidermis and at least to the superficial dermis. Following LSR
treatment using CO.sub.2 lasers, a high incidence of complications
can occur, including persistent erythema, hyperpigmentation,
hypopigmentation, scarring, and infection (e.g., infection with
Herpes simplex virus). LSR treatment with the Er:YAG laser has been
introduced as a more gentle alternative to the CO.sub.2 laser, due
to the lesser penetration depth of the Er:YAG pulsed laser. Using
the Er:YAG laser results in a thinner zone of thermal injury within
the residual tissue of the target area of the skin. However, LSR
that uses the Er:YAG laser produces side effects similar to those
made by LSR that uses the CO.sub.2 laser within the first days
after treatment.
[0009] A limitation of LSR using CO.sub.2 or Er:YAG lasers is that
ablative laser resurfacing generally can not be performed on the
patients with dark complexions. The removal of pigmented epidermis
tissue can cause severe cosmetic disfigurement to patients with a
dark complexion, which may last from several weeks up to years,
which is considered by most patients and physicians to be
unacceptable. Another limitation of LSR is that ablative
resurfacing in areas other than the face generally have a greater
risk of scarring. LSR procedures in areas other than the face
result in an increased incidence of an unacceptable scar formation
because the recovery from skin injury within these areas is not
very effective.
[0010] In an attempt to overcome the problems associated with LSR
procedures, a group of NCR techniques has emerged. These techniques
are variously referred to in the art as non-ablative resurfacing,
non-ablative subsurfacing, or non-ablative skin remodeling. NCR
techniques generally utilize non-ablative lasers, flashlamps, or
radio frequency current to damage dermal tissue while sparing
damage to the epidermal tissue. The concept behind NCR techniques
is that the thermal damage of only the dermal tissues is thought to
induce wound healing which results in a biological repair and a
formation of new dermal collagen. This type of wound healing can
result in a decrease of photoaging related structural damage.
Avoiding epidermal damage in NCR techniques decreases the severity
and duration of treatment related side effects. In particular, post
procedural oozing, crusting, pigmentary changes and incidence of
infections due to prolonged loss of the epidermal barrier function
can usually be avoided by using the NCR techniques.
[0011] Various strategies are presently applied using nonablative
lasers to achieve damage to the dermis while sparing the epidermis.
Nonablative lasers used in NCR procedures have a deeper dermal
penetration depth as compared to ablative lasers used in LSR
procedures. Wavelengths in the near infrared spectrum can be used.
These wavelengths cause the non-ablative laser to have a deeper
penetration depth than the very superficially-absorbed ablative
Er:YAG and CO.sub.2 lasers. The dermal damage is achieved by a
combination of proper wavelength and superficial skin cooling, or
by focusing a laser into the dermis with a high numerical aperture
optic in combination with superficial skin cooling. While it has
been demonstrated that these techniques can assist in avoiding
epidermal damage, one of the major drawbacks of these techniques is
their limited efficacies. The improvement of photoaged skin or
scars after the treatment with NCR techniques is significantly
smaller than the improvements found when LSR ablative techniques
are utilized. Even after multiple treatments, the clinical
improvement is often far below the patient's expectations. In
addition, clinical improvement is usually several months delayed
after a series of treatment procedures.
[0012] Another limitation of NCR procedures relates to the breadth
of acceptable treatment parameters for safe and effective treatment
of dermatological disorders. The NCR procedures generally rely on
an optimum coordination of laser energy and cooling parameters,
which can result in an unwanted temperature profile within the skin
leading to either no therapeutic effect or scar formation due to
the overheating of a relatively large volume of the tissue.
[0013] Yet another problem of non-ablative procedures relates to
the sparing of the epidermis. While sparing the epidermis is
advantageous in order to decrease the side effects related to
complete removal of the epidermis, several applications of NCR
procedures may benefit from at least partial removal of epidermal
structures. For example, photoinduced skin aging manifests not only
by the dermal alterations, but also by epidermal alterations.
[0014] A further problem of both ablative and nonablative
resurfacing is that the role of keratinocytes in the wound healing
response is not capitalized upon. Keratinocyte plays an active role
in the wound healing response by releasing cytokines when the
keratinocyte is damaged. During traditional ablative resurfacing
procedures, the keratinocytes are removed from the skin along with
the epidermis, thereby removing them from the healing process
altogether. On the other hand, in traditional non-ablative
procedures, the keratinocytes, which are located in the epidermis,
are not damaged, therefore they do not release cytokines to aid in
the healing process.
[0015] Another major problem with all LSR and NCR techniques now
used is the appearance of visible spots and/or edges after
treatment due to inflammation, pigmentation, or texture changes,
corresponding to the sites of treatment. Devices for LSR and NCR
produce macroscopic (easily seen) sexposure areas. For example,
laser exposure spot diameters typically vary from about 1 to 10 mm,
and NCR exposure spot diameters from about 3 to 50 mm. Some
devices, such as indense pulsed light devices, leave "boxes" of
skin response due to rectangular output patterns on the skin.
Patients do not like such spot or box patterns, easily seen as red,
brown or white areas ranging from on the order of millimeters to
centimeters in size, which remain for days or even years after
treatment.
[0016] Therefore, there is a need to provide a procedure and
apparatus that combine safe and effective treatment for improvement
of dermatological disorders with minimum side effects, such as
intra procedural discomfort, post procedural discomfort, lengthy
healing time, and post procedural infection.
SUMMARY OF THE INVENTION
[0017] It is therefore one of the objects of the present invention
to provide an apparatus and method that combines safe and effective
treatment for an improvement of dermatological disorders with
minimum side effects. Another object of the present invention is to
provide an apparatus and method that cause thermal skin damage to
only a fraction of a target area of skin.
[0018] These and other objects can be achieved with the exemplary
embodiment of the apparatus and method according to the present
invention, in which portions of a target area to be subjected to
irradiation are masked. The exemplary apparatus can include at
least one shielding member configured to mask at least one portion
of a target area of skin from electromagnetic radiation, in which
the shielding members are formed such that a minimal amount of
electromagnetic radiation is reflected back towards an
electromagnetic radiation source.
[0019] In another advantageous embodiment of the present invention,
electromagnetic radiation can be generated by an electromagnetic
radiation source, thus causing the electromagnetic radiation to be
applied to a target area of the skin. At least one portion of the
target area of the skin is then masked from the electromagnetic
radiation using a mask.
[0020] In yet another advantageous embodiment of the present
invention, an apparatus and method for treating dermatological
conditions is provided. In particular, a delivery module and
translator are utilized. The delivery module is configured to
direct electromagnetic radiation generated by an electromagnetic
radiation source to a predetermined area within a target area of
skin, wherein the predetermined area is located in a location
relative to the delivery module, and wherein the electromagnetic
radiation is adapted to cause thermal damage to epidermal tissue
and dermal tissue of the predetermined area within the target area
of the skin. The translator is capable of moving the delivery
module, such that the delivery module targets a plurality of
spatially separated individual exposure areas of the predetermined
area.
[0021] In a further advantageous embodiment of the present
invention, the electromagnetic radiation can be applied to a first
individual exposure area of the target area of the skin. The
electromagnetic radiation can then be applied to a second
individual exposure area of the target area of the skin, which is
separated from the first individual exposure area by a
non-irradiated skin section.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] For a more complete understanding of the present invention
and its advantages, reference is now made to the following
description, taken in conjunction with the accompanying drawings,
in which:
[0023] FIGS. 1A-1C show progressive illustrations of a first
exemplary embodiment of a fractional resurfacing system for
conducting various dermatological treatments at various stages of
use according to the present invention;
[0024] FIG. 2 shows a top view of a first exemplary embodiment of a
mask according to the present invention;
[0025] FIG. 3 shows a cross-sectional view of the mask of FIG.
2;
[0026] FIG. 4 shows a top view of a second exemplary embodiment of
the mask according to the present invention;
[0027] FIG. 5 shows a cross-sectional view of the mask of FIG.
4;
[0028] FIG. 6 shows a cross-sectional view of another variant of
the mask of FIG. 4;
[0029] FIGS. 7A and 7B show progressive illustrations of a second
exemplary embodiment of the fractional resurfacing system for
conducting various dermatological treatments at various stages of
use according to the present invention;
[0030] FIG. 8 shows a top view of small individual exposure areas
created by the fractional resurfacing system of FIGS. 7A and 7B;
and
[0031] FIG. 9 shows an exemplary embodiment of a system for
monitoring the location of the fractional resurfacing system of
FIGS. 7A and 7B.
[0032] Throughout the drawings, the same reference numerals and
characters, unless otherwise stated, are used to denote like
features, elements, components, or portions of the illustrated
embodiments. Moreover, while the present invention will now be
described in detail with reference to the Figures, it is done so in
connection with the illustrative embodiments.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0033] FIGS. 1A-9 illustrate various embodiments of a method and
apparatus for fractional resurfacing of a target area of skin.
Generally, the exemplary methods and apparatus deliver an
electromagnetic radiation to the patient's skin defined by various
patterns, so as to induce thermal injury of the skin surface
corresponding to such patterns and involving only a fraction of the
targeted surface area of the skin. Such technique combines the
efficacy of ablative resurfacing procedures with the minimal side
effects of non-ablative procedures. The delivery of the
electromagnetic radiation to the skin in a predetermined pattern is
achieved by either masking parts of the target area of the skin
surface in order to protect the masked parts of the skin surface
from the electromagnetic radiation, or by utilizing a light beam of
relatively small diameter which is scanned across the skin surface
by various means in order to generate a specific pattern for
affecting superficial thermal skin injury.
[0034] Fractional resurfacing is defined as the controlled
ablation, removal, destruction, damage or stimulation of multiple
small (generally less than 1 mm) individual exposure areas of skin
tissue with intervening spared areas of skin tissue, performed as a
treatment to improve the skin. The individual exposure areas may be
oval, circular, arced and/or linear in shape. The spatial scale of
fractional resurfacing is chosen to avoid the appearance of various
spots or boxes on a macroscopic scale, while still providing
effective treatment because the multiple small areas can be exposed
to greater than a minimal stimulus. For example, removal or
photothermal destruction of thousands of 0.1 mm diameter individual
exposure areas, spaced 0.2 mm apart, and extending into the skin up
to a depth of 0.5 mm, is well tolerated and produces effective
improvement of photoaging, without apparent spots and with rapid
healing. Spared skin between the individual exposure areas rapidly
initiates a wound healing response, which is better tolerated than
conventional LSR.
[0035] During the exemplary fractional resurfacing procedure of the
present invention, certain portions of the target area remain
undamaged, thereby preserving keratinocytes and melanocytes, which
serve as a pool of undamaged cells to promote reepithelialization.
This procedure differs from the traditional resurfacing procedures,
such that the entirety of the target area is damaged. In
traditional resurfacing procedures, reepithelialization is
generally initiated from the depth of an undamaged follicular
epithelium. Because the traditional procedures remove the entire
epithelium, an important factor for the time of reepithelialization
is the density of follicles. The vellus hair density of the face
(439 hairs/cm.sup.2) of the subject is significantly higher than on
the back of the subject (85 hairs/cm.sup.2). Therefore, the face of
the subject, generally experiences better and faster
reepithelization in comparison to other body areas with a lower
hair density.
[0036] The resurfacing of the dark pigmented skin is currently not
very frequently performed because of the prolonged repigmentation
process. The fractional resurfacing technique improves the
repigmentation process but, melanocytes do not migrate well. By
sparing certain portions of the target area of the skin, the travel
distance of melanocytes can be decreased, thereby reducing the
repigmentation time and allowing the resurfacing of all skin
types.
[0037] FIGS. 1A-1C illustrate a progressive use of a first
exemplary embodiment of a fractional resurfacing system 100 for
conducting various dermatological treatments using electromagnetic
radiation ("EMR") and generating a superficial pattern of skin
damage of a target area by using a mask according to the present
invention. The system 100 may be used for collagen remodeling,
removal of unwanted pigment or tattoo, and/or other dermatological
applications. As shown in FIGS. 1A-1C, the system 100 includes a
case 101, a control module 102, an EMR source 104, delivery optics
106 and a mask 108. The case 101 contains the control module 102,
the EMR source 104, and the delivery optics 106. An aperture is
provided through a sidewall of the case 101. The mask 108 is placed
in registration with the aperture formed through the sidewall of
the case 101. By placing the mask 108 in registration with the
aperture of the case 101, the focal length of the EMR emitted by
the delivery optics 106 is fixed, and can be configured such that
it does not impact the side of the mask 108, so as to cause
injuries to the operator of the fractional ablation system 100. The
control module 102 is in communication with the EMR source 104,
which in turn is operatively connected to the delivery optics
106.
[0038] In one exemplary variant of the present invention, the
control module 102 can be in wireless communication with the EMR
source 104. In another variant, the control module 102 may be in
wired communication with the EMR source 104. In another exemplary
variant of the present invention, the control module 102 can be
located outside of the case 101. In another variant, the EMR source
104 is located outside of the case 101. In still another variant,
the control module 102 and the EMR source 104 are located outside
of the case 101. It is also possible that the mask 108 is not
connected to the case 101.
[0039] The control module 102 provides application specific
settings to the EMR source 104. The EMR source 104 receives these
settings, and generates EMR based on these settings. The settings
can control the wavelength of the EMR, the energy delivered to the
skin, the power delivered to the skin, the pulse duration for each
EMR pulse, the fluence of the EMR delivered to the skin, the number
of EMR pulses, the delay between individual EMR pulses, the beam
profile of the EMR, and the size of the area within the mask
exposed to EMR. The energy produced by the EMR source 104 can be an
optical radiation, which is focused, collimated and/or directed by
the delivery optics 106 to the mask 108. The mask 108 can be placed
on a target area of a patient's skin, and may provide a damage
pattern on the target area of the skin with a fill factor in the
range from 0.1% to 90%. The fill factor is the percentage of the
target area exposed to the EMR that is emitted by the EMR source
106.
[0040] In one exemplary embodiment, the EMR source 106 is one of a
laser, a flashlamp, a tungsten lamp, a diode, a diode aray, and the
like. In another exemplary embodiment, the EMR source 106 is one of
a CO.sub.2 laser and a Er:YAG laser.
[0041] Prior to being used in a dermatological treatment, the
system 100 shown in FIG. 1A can be configured by a user. For
example, the user may interface with the control module 102 in
order to specify the specific settings usable for a particular
procedure. The user may specify the wavelength of the EMR, the
energy delivered to the skin, the power delivered to the skin, the
pulse duration for each EMR pulse, the fluence of the EMR delivered
to the skin, the number of EMR pulses, the delay between individual
EMR pulses, the beam profile of the EMR, and the size of the area
within the mask exposed to EMR. The EMR source 104 may be set to
produce a collimated pulsed EMR irradiation with a wavelength
ranging from 400 to 11,000 nm, and preferably near 3.0 .mu.m when
using an Er:YAG laser and near 10.6 .mu.m when using a CO.sub.2
laser as the EMR source. The collimated pulsed EMR irradiation may
be applied which has a pulse duration in the range of 1 .mu.s to 10
s, preferably in the range of 100 .mu.s to 100 ms, and more
preferrably in the range of 0.1 ms to 10 ms, and fluence in the
range from 0.01 to 100 J/cm.sup.2, and preferably in the range from
1 to 10 J/cm.sup.2. The applied EMR should be able to achieve at
least a temperature rise within the exposed areas of the skin that
is sufficient to cause thermal damage to the epidermis 110 and/or
the dermis 112. The peak temperature sufficient to cause thermal
damage in the exposed tissues is time dependant and at least in the
range of 45.degree. C. to 100.degree. C. For exposure times in the
range of 0.1 ms to 10 ms the minimum temperature rise required to
cause thermal damage is in the range of approximately 60.degree. C.
to 100.degree. C. The depth of thermal damage can be adjusted by
proper choice of wavelength, fluence per pulse and number of
pulses.
[0042] During the dermatological treatment, the system 100 produces
EMR 120 which is directed to the target area of the skin 114, as
shown in FIG. 1B. The EMR 120 may be pulsed multiple times to
create the appropriate affect and irradiation in the target area of
the skin 114.
[0043] After the dermatological treatment is completed, the target
area of the skin 114 is likely damaged in specific places. The
application of the EMR 120 creates a prearranged thermal skin
damage 130 in an epidermal tissue 110 and the dermal tissue 112. It
should be noted that the thermal skin damage 130 extends through
the epidermal tissue 110 and into the dermal tissue 112 only to a
predetermined depth. The mask 108 controls in a location where the
thermal skin damage 130 is created. The thermal skin damage 130
generally accounts for only 0.1% to 90% of the skin surface area in
the target area. A fill factor is defined as the ratio of surface
area of the target area of skin thermally damaged by EMR to surface
area of the target area of the skin.
[0044] In an exemplary embodiment of the present invention, the
thermal skin damage 130 may extend through the epidermal tissue 110
and through the entirety of the dermal tissue 112. In another
exemplary embodiment of the present invention, the thermal skin
damage 130 may occur principally in the dermal tissue 112 and minor
skin damage may occur in the epidermal tissue 110. It should be
noted that it is possible that the pentration depths of each of the
micro areas of the thermal skin damage 130 may be different from
one another or same as one another. This may be because pigment
removal or dermal removal can be separately regulated by varying
the density of the micro-damaged areas for either the deeper or
superficial damages, e.g., dermal remodeling and pigment
adjustment, respectively.
[0045] FIG. 2 illustrates a top view of a first exemplary
embodiment of the mask 108 according to the present invention. The
mask 108 includes shielding structured 202. The diameter of the
mask 108 should preferably be matched to greater than the size of
the diameter of the target area. The target area is defined as the
area targeted by the collimated EMR emitted by the EMR source 104,
which can be in the range 1-100 mm in diameter, preferably within
the range of 5 to 20 mm. This diameter of most of the currently
commercially available CO.sub.2 and Er:YAG laser systems can match
the diameter of the exposed area The width of shielding structures
202 within the mask 108 should be in the range of 50 to 300 .mu.m.
The width of the apertures of the mask 108 that are formed by the
shielding structures should be in the range of 10-1000 .mu.m, and
preferably in the range of 50 to 300 .mu.m. The shielding-exposure
ratio surface area covered by the of shielding structures 202 to
the surface area exposed by the apertures effects the clinical
efficacy and provides side effects of the dermatological treatment.
This also determines the fill factor and the pattern of the thermal
damage of the skin. The depth of thermal damage is determined by
the number of pulses, the fluence of the EMR and the wavelength of
the EMR. The shielding-exposure ratio of the mask 108 will vary for
different dermatological treatments, particular patient needs,
particular patient indications, skin types and body areas.
[0046] The mask 108 may have a large shielding-exposure ratio at
the edge of the mask 108 to generate a transition zone at the edge
of resurfaced area This technique is called "feathering." It avoids
a sharp macroscopically visible demarcation between treated and
untreated areas. In another preferred embodiment, a mask may be
used that has a large shielding-exposure ratio at the edge of a
conventionally resurfaced area to generate a transition zone.
[0047] The surface of the mask 108 should preferably have a minimal
absorption at the wavelength generated by the EMR source 104 for
the particular dermatological process. Such absorption can decrease
the undesirable heating of the mask 108. The mask 108 may be coated
by a metal material for affectuating a minimal absorption of the
EMR. The design of the shielding structures 202 of the mask 108, a
cross-section A-A of which is shown in FIG. 3; generally takes into
consideration safety aspects, including a back-reflected EMR in
order to avoid EMR inflicted accidents. The shielding structures
202 are shaped in a peaked manner to minimize the amount of back
reflected EMR. Also, with the mask 108 being connected to the case
101 the distance between the delivery optics 106 and the mask 108
is fixed, thereby minimizing the chances that EMR would be
reflected back towards the user by hitting the edge of the mask
108. Additionally, the microstructure of the mask 108 can have a
periodicity preferably in the range of the wavelength of the EMR
emitted by the delivery optics 106. This configuration can diffuse
the collimated EMR emitted by the delivery optics 106 into a highly
scattered beam so as to decrease the risk of EMR-related
accidents.
[0048] In one exemplary embodiment, the metal coating of the mask
108 may be composed of gold, silver, or copper materials, or the
like. In another exemplary embodiment, the microstructure of the
surface of the mask 108 may have a periodicity in the range of the
wavelength of the EMR emitted by the delivery optics 106.
[0049] The mask 108 may also have a configuration so as to provide
effective skin cooling during the exposure thereof with the EMR
radiation. Skin cooling provides significant anesthetic effects,
and has other advantages related to the pattern induced by the EMR
radiation. The mask 108 can be cooled prior to the beginning of the
dermatological procedure, during the procedure by spraying an
evaporative agent or a precooled liquid onto the mask 108 between
the successive EMR pulses, or during the procedure by introducing a
cool or cold liquid into microchannels 302 (shown in FIG. 3)
running through the mask 108. The cooling of the mask 108 has a
secondary advantage in that such cooling of the mask 108 decreases
the rate of the EMR absorption by the mask 108, as the rate of the
EMR absorption by the metals increases with the increasing
temperature.
[0050] In order to provide skin cooling as described above, the
temperature of the mask 108 should be in the range of 37.degree. C.
to -20.degree. C., and preferably 10.degree. C. to -4.degree. C.
The mask 108 can both protect and cool the portions of the skin
surface that are not exposed to EMR emitted by the EMR source 104.
In addition to cooling and shielding portions of the skin surface,
the mask 108 allows the debris ejected during ablative procedures
to escape, and thereby not interfere with the beam delivery for
successive pulses. For example, the areas that are not exposed to
the laser are being cooled by the mask 108, i.e., the areas that
are provided between the affected areas. In another exemplary
embodiment, all areas (i.e., both the affected and nonaffected
areas) are cooled to provide anesthesia, and to reduce
over-damaging the superficial levels of the damaged areas.
[0051] FIG. 3 illustrates a cross-section A-A of the mask 108 of
FIG. 2. The cross-section A-A shows the microchannels 302 that run
through at least the shielding structures 202 of the mask 108. A
cooling agent, e.g., either a liquid or gas, may circulate through
these microchannels 302 during a dermatological procedure, thereby
removing heat from the protected skin and the mask 108 itself.
[0052] FIG. 4 illustrates a top view of a second embodiment of the
mask 400 according to the present invention. The mask 400 differs
from the mask 108 only in the layout and design of the shielding
structures 402. The details of the mask 400 are in all other
respects substantially similar to those of the mask 108. The
shielding structures 402 are cylindrical in shape, as indicated in
cut-away cross-sections B-B and C-C, shown in FIGS. 5 and 6,
respectively. The shielding structures 402 of the mask 400 contain
microchannels 502 and 602, which are capable of carrying a cooled
liquid or gas so as to cool the mask 400 and the masked portions of
the target area of the skin. The microchannels 502, 602 intersect
at the intersection of the shielding structures 402.
[0053] In an exemplary embodiment of the present invention, the
microstructures 502, 602 are not required to intersect at the
intersection of the shielding structures 402.
[0054] In an exemplary embodiment of the present invention, the
mask 108 is an ablative mask. An ablative mask includes multiple
sections having various thicknesses. Prior to a procedure, the
ablative mask is attached to the skin with an adhesive. During the
proceedure having multiple EMR pulses, the ablative mask is
ablated, such that the thickness of each of the multiple sections
is diminished, potentially gradually exposing different areas of
the skin to the EMR pulses. The ablative mask can be composed of
various materials including polymer materials. The ablative mask
can be easily produced by imprinting a pattern therein.
[0055] A particular dermatological treatment, i.e., the removal of
tattoos, shall be described in further detail. Tattoo removal may
be performed with a combination of an ablative EMR and the mask
108. In particular, utilizing the CO.sub.2 laser and/or the Er:YAG
laser may be appropriate for this application. During this
dermatological procedure, the tattoo can be exposed to ablative EMR
radiation with the mask 108 providing a fill factor of the target
area in the range of 10 to 90%, and preferably in the range of 25
to 70%. Preferably, the mask 108 is applied under pressure to the
skin, which minimizes the blood flow during the procedure. Limiting
the blood flow during the procedure allows a deeper ablation of the
skin surface before blood can interfere with the EMR radiation,
thereby limiting the ablation depth. Multiple pulses of ablative
EMR radiation can be applied to the individual areas of the tattoo
until the desired ablation depth is reached. The desired ablation
depth can be in the range of 100 .mu.m to 5 mm. This exemplary
procedure can cause a specific fraction of the tattoo that is
controlled by the mask 108 to be immediately ablated. Wound healing
may be enhanced because only a fraction of the surface is
ablated.
[0056] The removal of tattoos utilizing fractional resurfacing may
be augmented using a short pulsed EMR, preferentially absorbed by
the tattoo particles either before or after the application of the
fractional resurfacing. In a short pulsed-laser application, the
laser may be pulsed for short periods of time, preferably for less
than 1 .mu.s in duration. The EMR soruce used in this type of
procedure can preferably be a Q-switched ruby laser, a Nd:YAG
laser, a KTP laser and/or an Alexandrite laser. The objective of
this procedure is to release the pigment within areas that are not
exposed to fractional resurfacing ablation. The released pigment
particles may drain in the ablated channels, and can be flushed
from the area after the procedure by the blood resident in the
target area and/or an external rinsing agent, e.g., saline. Several
such procedures may be utilized until the desired clearance of the
tattoo has occurred.
[0057] As an alternative to the fractional resurfacing using a
mask, a second embodiment of a fractional resurfacing system 700,
as shown as the progressive use thereof in FIGS. 7A-7B, can be
used. The system 700 can include a case 701, a control module 702,
an electromagnetic radiation ("EMR") source 704, delivery optics
706, an x-y translator 708 and an optically transparent plate 709.
The case 701 may contain the control module 702, the EMR source
704, the delivery optics 706 and the translator 708. As with the
system 100, an aperture may be formed through a sidewall of the
case 701. The optically transparent plate 709 may be placed in
registration with the aperture that is formed through the sidewall
of the case 701. Placing the plate 709 in registration with the
aperture formed through the sidewall of the case 701 seals the
system 700, which contains sophisticated translation mechanisms,
e.g., the delivery optics 706 and the translator 708. The control
module 702 is in communication with the translator 708 and the EMR
source 704, and the EMR source 704 is operatively connected to the
delivery optics 706.
[0058] In one exemplary variant of the present invention, the
control module 702 can be located outside of the case 701. In
another exemplary variant, the EMR source 704 is located outside of
the case 701. In still another variant, the control module 702 and
the EMR source 704 are located outside of the case 701.
[0059] The control module 702 provides application specific
settings to the EMR source 704, and controls the x-y translator
708. The EMR source 704 receives these settings, and generates EMR
based on these settings. The settings can control the wavelength of
the energy produced, the intensity of the energy produced, the
fluence of the energy produced, the duration of the dermatological
procedure, the pulse length of each of the EMR pulses administered
during the procedure, the spatial distance between individual
exposure areas 716 (shown in FIG. 8), the shape of individual
exposure areas 716, the pattern defined by individual exposure
areas 716, and the fill factor of the target area. It should be
noted that the thermal skin damage caused to individual exposure
areas 716 extends through the epidermal tissue 710 and into the
dermal tissue 712 only to a predetermined depth. The EMR source 704
can be a laser or other light source. The EMR produced by the EMR
source 704 can be delivered through a fiber, waveguide or mirrors
if the source is located outside the delivery optics 706.
Alternatively, if the EMR source 704 is located in a close vicinity
to the skin 714, the EMR source 704 produces the EMR directly to
the delivery optics 706. The energy produced by the EMR source 704
may be focused and/or directed by focusing optics in the delivery
optics 706 to one of the an individual exposure areas 716, shown in
FIG. 8. Each of the individual exposure areas 716 are located
within the target area of the skin 714, and are relatively small
compared to the target area of the skin 714. The target area of the
skin 714 can generally be 1 cm.sup.2 in size and each of the
individual exposure areas 716 may be 100 .mu.m in diameter.
[0060] In an exemplary embodiment of the present invention, the
optics of the delivery optics 706 may contain a beam collimator or
focusing optics. In another exemplary embodiment of the present
invention, the thermal skin damage caused to individual exposure
areas 716 may extend through the epidermal tissue 710 and through
the entirety of the dermal tissue 712. In another exemplary
embodiment of the present invention, the thermal skin damage caused
to individual exposure areas 716 may principally occur in the
dermal tissue 712 and only minor thermal damage may occur in the
epidermal tissue 710. It should be noted that it is possible that
the pentration depths of each of the micro areas of the thermal
skin damage caused to individual exposure areas 716 may be
different from one another or same as one another. This may be
because pigment removal or dermal removal can be separately
regulated by varying the density of the micro-damaged areas for
either the deeper or superficial damages, e.g., dermal remodeling
and pigment adjustment, respectively. In a further exemplary
embodiment of the present invention, the predetermined depth of the
thermal skin damage caused to individual exposure areas 716 is
approximately 300 .mu.m.
[0061] Prior to use in a dermatological treatment and similarly to
the use of system 100, the system 700, as shown in FIG. 7A, can be
configured by a user. In particular, the user interfaces with the
control module 702 in order to specify the specific settings to be
used for a particular procedure. The user may specify the desired
damage pattern, the wavelength of the energy produced by the EMR
source 704, the intensity of the energy produced, the fluence of
the energy produced, the length of time the treatment will take and
the pulse duration of the EMR source 704. During the treatment, the
translator 708 moves the delivery optics 706 across sequential
portions of the target area of the skin 714 in order to treat the
entire target area. The target area is treated when the system 700
delivers EMR to individual exposure areas 716 of the target area
The individual exposure areas 716 may be targeted serially and/or
in parallel. When one of the portions of the target area has been
completely treated, the system 700 is moved to the next portion of
the target area. For example, the system 700 is moved at the
completion of irradiation of each portion of the target area until
the desired skin surface damage pattern is achieved for the entire
area. The system 700 can be moved using discrete movements from one
sequential portion to the next, i.e., stamping mode, or using
continuous movement across the skin surface, i.e., continuous
scanning mode. In either case, the movement of the delivery optics
706, driven by the translator 708, is controlled by the control
unit 702 and likely matched with the movement of the system 700 by
the operator (or the user) in order to provide the desired surface
damage pattern to the target area of the skin 714.
[0062] In an exemplary embodiment of the present invention, the
system 700, while operating in the continuous scanning mode, can
deliver EMR to a particular individual exposure area 716, then,
after exposure of such area 716, translate along the skin of the
target area, and thereafter deliver a further EMR to another
individual exposure area 716 separated from the previous particular
individual exposure area 716 by non-irradiated region. In another
exemplary embodiment of the present invention, the system 700,
while operating in the continuous scanning mode, can deliver EMR to
a particular group of individual exposure areas 716, for example
the top row of individual exposure areas 716 (shown in FIG. 8),
then, after exposure of such areas 716, translate along the skin of
the target area, and deliver a further EMR to another group of
individual exposure areas 716, for example the second row of
individual exposure areas 716 (shown in FIG. 8), separated from the
particular group of individual exposure areas 716 by non-irradiated
areas.
[0063] In an exemplary embodiment of the present invention, the
system 700 includes a position sensor, which is in communication
with the control module 702. The position sensor is capable of
sensing the relative velocity as between the skin 114 and the case
701. The position sensor can be an optical mouse, wheels, track
ball, conventional mouse, and the like.
[0064] In another exemplary embodiment of the present invention,
the system 700 targets individual exposure areas 716 one at a time.
Administering EMR to the individual exposure areas 716 one at a
time decreases the amount of pain experienced by the subject. A
time period of 50 milliseconds may be provided between each
administration of EMR to each of the individual exposure areas 716.
Thereby controlling the amount of pain experienced by the subject
and avoiding bulk heating of the tissue targeted by the system 700.
In still another exemplary embodiment of the present invention, the
system 700 targets a predetermined number of individual exposure
areas 716 at a time. Limiting the number of predetermined target
areas 716 targeted at one time limits the amount of pain
experienced by a patient. Targeting a large number of individual
exposure areas 716 at one time requires targeting a collectively
large area of skin, which excites many nerve endings
simultaneously, therefore causing the subject a proportionally
large amount of pain. Targeting fewer individual exposure areas 716
causes a subject less pain, but causes a proceedure to take
longer.
[0065] In a further exemplary embodiment of the present invention,
the system 700 creates individual exposure areas 716 having a
separation distance between each of the individual exposure areas
716 of approximately at least 125 .mu.m and at most 500 .mu.m,
preferrably, the separation distance is approximately at least 250
.mu.m.
[0066] Before the initiation of a dermatological procedure, the
optically transparent plate 709 can be brought in a direct contact
with the skin surface covering the target area The optically
transparent plate 709 can be composed out of any material having
good thermal conductivity, and being transparent over a broad range
of the visible and near infrared spectrum. The plate 709 seals the
system 700, which contains sophisticated translation mechanisms,
and provides cooling to the target area of the skin 714. The plate
709 can provide cooling to the target area of the skin 714 in two
ways: heat conduction and heat convection. Heat conduction
transfers heat through the optically transparent plate 709 to the
case 701, which provides cooling by circulating a coolant agent
through the case 701 of the system 700. The entire optically
transparent place 709 can also be cooled prior to application to
the target area of the skin 714. Alternatively, heat convection can
be utilized for this procedure. An evaporating agent sprayed onto
the optical window or onto a compartment in good thermal contact
with the window may also be utilized The delivery of the
evaporating agent can be administered during the procedure between
EMR pulses through a valve, which can be controlled by a thermostat
with a temperature sensor at the optical plate.
[0067] In one embodiment, of the present invention the optically
transparent plate 709 can be composed of sapphire or quartz. In
another embodiment of the present invention, the system 700 can be
moved multiple times over the same portion of the skin 714 until
the desired fill factor is achieved. In yet another embodiment,
multiple procedures can be performed to achieve the desired
effect.
[0068] During the dermatological procedure, the EMR source 704
emits EMR having a wavelength in the range of 400-12,000 nm.
Preferably the EMR has a wavelength in one of the following ranges:
1,300 to 1,600 nm, 1,850 to 2,100 nm, 2,300 to 3,100 nm and around
10,640 nm. Depending on the application, a single wavelength or a
combination of different wavelengths may be utilized. The EMR
source 704 can be a diode laser, a fiber laser, a solid state
laser, a gas laser, and the like. The pulse duration can range from
100 .mu.s to 100 ms, and preferably in the range from 500 .mu.s to
15 ms, and more preferrably in the range from 1.5 ms to 5 ms. The
energy density per pulse within an individual exposure area 716 may
be in the range of 0.1 to 100 J/cm.sup.2, preferably 1 to 32
J/cm.sup.2, and more preferrably 1.5 to 3 J/cm.sup.2. The energy
per pulse within an individual exposure area 716 may be in the
range of 1 mJ and 10 mJ, and preferrably 5 mJ.
[0069] In an exemplary embodiment of the present invention, the EMR
source 704 is a 1.5 .mu.m laser system, preferrably a Reliant FSR
prototype, manufactured by Reliant Technologies, Palo Alto, Calif.,
is used.
[0070] After the dermatological treatment is completed, the target
area of the skin 714 is damaged in a specific pattern. The
application of EMR creates the thermal skin damage in an epidermis
710 and a dermis 712 of the skin 714. The radiation provided by the
EMR source 704 is delivered to the skin 714 within multiple small
individual exposure areas 716, shown in FIG. 7B, through the
delivery optics 706. The delivery optics 706 can deliver multiple
individual beams across the target area of the skin surface.
[0071] FIG. 8 illustrates a top view of the small individual
exposure areas 716 of the epidermis. The shape of the individual
exposure areas 716 may be circular (shown in FIG. 8), elliptical,
rectangular, linear or irregular with a lateral diameter of the
smallest dimension in the range of 1-500 .mu.m. The fill factor of
the target area can be approximately 20-40%.
[0072] The system 700 can create multiple individual exposure areas
716 through heating, ablation, removal, photothermal coagulation,
thermal necrosis and/or stimulation. The multiple areas can be
exposed sequentially or simultaneously. Sequential exposure may be
achieved by scanning or moving an energy source which may be either
pulsed, shuttered or continuous. Simultaneous exposure can be
achieved, for example, by an array of sources or a multi-array of
lenses. The array of sources may be a uni-dimensional array, a
bi-dimensional array or the like. The array can be moved relative
to the skin, and one or multiple passes of treatment can be
performed in a target area.
[0073] FIG. 9 illustrates an exemplary embodiment of a monitoring
system 900 according to the present invention. The monitoring
system 900 tracks the movement of the system 700, and feeds such
positional information to the control module 702. The control
module 702 utilizes this information to appropriately instruct the
translator 708 to position the delivery optics 706, such that the
appropriate damage pattern is achieved across the target area of
the skin 714. The monitoring system 900 may use a computer 902, a
mouse 904, and a charge coupled device ("CCD") camera 906. In
particular, the computer 902 receives the positional information
about the system 700 from the CCD camera 906. The computer then
updates the control module 702 based on this positional information
as to the current position of the system 700. The control module
702 utilizes this information to cause the system 700 to create the
appropriate damage pattern on the skin 714 within the target area.
In addition, the monitoring system can utilize additional motion
detecting devices, including, wheels or any other motion
sensor.
[0074] The shape of the individual exposure areas 716 and the
relative pattern represented by all of the individual exposure
areas 716 may vary. The individual exposure areas 716 can have a
circular, elliptical, rectangular, linear or irregular shape. The
average distance between individual regions of unexposed skin
surface may be in the range between 10 to 2000 .mu.m, and
preferably in the range of 100 to 500 .mu.m. The macroscopic
pattern of the individual exposure areas 716 may be a field of
uniformly distributed individual exposure areas 716 with constant
spacing throughout the target area, randomly distributed individual
exposure areas 716 within the target area, and/or regularly
distributed individual exposure areas 716 with constant average
spacing with randomly shifted location. In particular, having
regularly distributed individual exposure areas 716 with constant
average spacing with randomly shifted location may be useful to
minimize undesirable effects, which may occur during multiple
treatments. Such multiple treatments are utilized to cover the
entire area as homogeneously as possible by the individual exposure
areas 716 during the course of multiple treatments. However,
uniformly distributed individual exposure areas 716 with constant
spacing throughout the target area may create unwanted spatial
distributions similar to moire patterns, resulting in spatial
interference macroscopic patterns generated with a distance in
between the areas of exposure which have a significant spatial
period. In order to minimize the occurrence of moire patterns, a
randomized shift within the range of 10 to 50% of the average
distance between individual exposure areas 716 during a single scan
may be utilized.
[0075] The treatment can be performed in by a single treatment
covering the skin surface with a specific surface damage pattern,
or by multiple treatments either performed at the same visit or
during different treatment visits. Individual or multiple exposures
can be used to achieve the appropriate thermal damage in particular
individual exposure areas 716.
[0076] Fractional resurfacing may cause portions of the epidermis
to be thermally damaged or ablated, thereby reducing the efficacy
of the barrier function of the epidermis and in particular
decreasing the stratum corneum. This facilitates the delivery of
drugs or specific substances to the dermis and epidermis which can
either enhance the effects of the treatment, or decrease the side
effects caused by partial damage of the epidermis and/or dermis.
Groups of drugs and substances, which may enhance the efficacy of
skin remodeling include growth factors, collagen byproducts,
collagen precursors, hyaluronic acid, vitamins, antioxidants, amino
acids and supplemental minerals among others. Groups of drugs and
substances, which may decrease side effects, can be steroidal
anti-inflammatory drugs, non-steroidal anti-inflammatory drugs,
antioxidants, antibiotics, antiviral drugs, antiyeast drugs and
antifungal drugs.
[0077] In an exemplary embodiment of the present invention, the
vitamins that are used may be vitamin C and/or vitamin E. The
supplemental minerals used are copper and zinc. The antioxidants
can be vitamin C and/or vitamin E.
[0078] In a clinical observation, enhanced wound healing was
observed for fractional resurfacing as compared to conventional
resurfacing. The forearm skin of a white, male Caucasian was
exposed to pulsed CO.sub.2 laser radiation with identical settings
of the illuminating laser beam with a beam diameter of
approximately 3 mm, a Coherent Ultra Pulse Laser, CPG handpiece, at
approximately 300 mJ/pulse. One area was exposed to the laser beam
without benefit of a mask while another area was partially shielded
by a cooled mask. More pronounced erythema was evident at the
conventionally resurfaced test site as compared to the fractionally
resurfaced test site.
[0079] The fill factor of the target area may be monitored by
sensing the electrical impedance of the skin from a location on the
skin within the target area to a remote location on the skin
outside of the target area during or after treatment. An indicator
capable of staining the defects in the stratum corneum (for
example, trypan glue) or transdermal waterloss are effective
indicators of the fill factor of the target area.
[0080] The foregoing merely illustrates the principles of the
invention. Various modifications and alterations to the described
embodiments will be apparent to those skilled in the art in view of
the teachings herein. It will thus be appreciated that those
skilled in the art will be able to devise numerous techniques
which, although not explicitly described herein, embody the
principles of the invention and are thus within the spirit and
scope of the invention.
* * * * *