U.S. patent application number 15/302436 was filed with the patent office on 2017-02-02 for band transducer ultrasound therapy.
The applicant listed for this patent is Ulthera, Inc.. Invention is credited to Charles D. Emery, Joshua D. Hope, Michael T. Peterson.
Application Number | 20170028227 15/302436 |
Document ID | / |
Family ID | 54324468 |
Filed Date | 2017-02-02 |
United States Patent
Application |
20170028227 |
Kind Code |
A1 |
Emery; Charles D. ; et
al. |
February 2, 2017 |
BAND TRANSDUCER ULTRASOUND THERAPY
Abstract
Embodiments of a dermatological cosmetic treatment and/or
imaging system and method can include use of transducer to create a
linear thermal treatment zone at a focal depth to form a band
shaped treatment area. The system can include one or more
ultrasound transducers, a cylindrical transduction element, an
imaging element, a hand wand, a removable transducer module, a
control module, and/or graphical user interface. In some
embodiments, a coated transducer may be used to provide more
consistent treatment in cosmetic procedures, including brow lifts,
fat reduction, sweat reduction, and treatment of the decolletage.
Skin tightening, lifting and amelioration of wrinkles and stretch
marks are provided. Treatment may include heating of tissue for a
duration to deactivate a percentage of cells in the treatment
region.
Inventors: |
Emery; Charles D.; (Gilbert,
AZ) ; Peterson; Michael T.; (Scottsdale, AZ) ;
Hope; Joshua D.; (Gilbert, AZ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Ulthera, Inc. |
Mesa |
AZ |
US |
|
|
Family ID: |
54324468 |
Appl. No.: |
15/302436 |
Filed: |
April 13, 2015 |
PCT Filed: |
April 13, 2015 |
PCT NO: |
PCT/US15/25581 |
371 Date: |
October 6, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61981660 |
Apr 18, 2014 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61N 2007/0091 20130101;
A61N 2007/0065 20130101; A61N 2007/0082 20130101; A61N 7/02
20130101; G10K 11/30 20130101; A61B 2017/00084 20130101; A61B
2017/00106 20130101; A61N 2007/0034 20130101; G10K 11/352 20130101;
A61N 2007/0078 20130101 |
International
Class: |
A61N 7/02 20060101
A61N007/02; G10K 11/35 20060101 G10K011/35; G10K 11/30 20060101
G10K011/30 |
Claims
1. An ultrasound transduction system, comprising: a cylindrical
transduction element; and a power source configured to drive the
cylindrical transduction element, wherein the cylindrical
transduction element is configured to apply ultrasonic energy to a
linear focal zone at a focal depth, wherein the cylindrical
transduction element comprises a first surface and a second
surface, wherein the first surface comprises an electrically
conductive coating, wherein the second surface comprises at least
one electrically conductive coated region and at least one region
that is not coated with an electrically conductive coating, wherein
the at least one coated region on the second surface comprises a
conductive material that forms an electrode when the power source
is in electric communication with the at least one coated region,
wherein the at least one coated region on the second surface is
configured to reduce edge noise at the linear focal zone at the
focal depth, wherein the reduction of edge noise reduces a variance
in focal gain in a range of 0.01-10.
2. (canceled)
3. The ultrasound transduction system according to claim 1, wherein
the first surface is a concave surface and the second surface is a
convex surface.
4. (canceled)
5. The ultrasound transduction system according to claim 1, wherein
the cylindrical transduction element is housed within an ultrasonic
hand-held probe, wherein the ultrasonic probe comprises: a housing,
the cylindrical transduction element, and a motion mechanism;
wherein the ultrasound transducer is movable within the housing,
wherein the motion mechanism is attached to the ultrasound
transducer and configured to move the ultrasound transducer along a
linear path within the housing.
6. The ultrasound transduction system according to claim 5, wherein
the motion mechanism automatically moves the cylindrical
transduction element to heat a treatment area at the focal depth to
a temperature in a range between 40-65 degrees Celsius.
7. The ultrasound transduction system according to claim 1, wherein
the reduction of edge noise facilitates the production of a uniform
temperature in a treatment area.
8. (canceled)
9. (canceled)
10. (canceled)
11. (canceled)
12. The ultrasound transduction system according to claim 1,
wherein the power source is configured to drive the cylindrical
transduction element to produce a temperature in a range of 42-55
degrees Celsius in a tissue at the focal depth.
13. (canceled)
14. The ultrasound transduction system according to claim 1,
further comprising one or more imaging elements, wherein the
cylindrical transduction element has an opening configured for
placement of the one or more imaging elements.
15.-50. (canceled)
51. An ultrasound transduction system, comprising: a cylindrical
transduction element; and a power source configured to drive the
cylindrical transduction element, wherein the cylindrical
transduction element is configured to apply ultrasonic energy to a
linear focal zone at a focal depth, wherein the cylindrical
transduction element comprises a first surface and a second
surface, wherein the first surface comprises an electrically
conductive coating, wherein the second surface comprises at least
one electrically conductive coated region and at least one region
that is not coated with an electrically conductive coating, wherein
the at least one coated region on the second surface comprises a
conductive material that forms an electrode when the power source
is in electric communication with the at least one coated region,
wherein the at least one coated region on the second surface is
configured to reduce edge noise at the linear focal zone at the
focal depth, wherein the reduction of edge noise reduces a peak
such that a variance of an intensity around the focal depth is 5 mm
or less.
52. The ultrasound transduction system according to claim 51,
wherein the first surface is a concave surface and the second
surface is a convex surface.
53. The ultrasound transduction system according to claim 51,
wherein the cylindrical transduction element is housed within an
ultrasonic hand-held probe, wherein the ultrasonic probe comprises:
a housing, the cylindrical transduction element, and a motion
mechanism; wherein the ultrasound transducer is movable within the
housing, wherein the motion mechanism is attached to the ultrasound
transducer and configured to move the ultrasound transducer along a
linear path within the housing.
54. The ultrasound transduction system according to claim 53,
wherein the motion mechanism automatically moves the cylindrical
transduction element to heat a treatment area at the focal depth to
a temperature in a range between 40-65 degrees Celsius.
55. The ultrasound transduction system according to claim 51,
wherein the reduction of edge noise facilitates the production of a
uniform temperature in a treatment area.
56. The ultrasound transduction system according to claim 51,
wherein the power source is configured to drive the cylindrical
transduction element to produce a temperature in a range of 42-55
degrees Celsius in a tissue at the focal depth.
57. The ultrasound transduction system according to claim 51,
further comprising one or more imaging elements, wherein the
cylindrical transduction element has an opening configured for
placement of the one or more imaging elements.
58. An ultrasound transduction system, comprising: a cylindrical
transduction element; and a power source configured to drive the
cylindrical transduction element, wherein the cylindrical
transduction element is configured to apply ultrasonic energy to a
linear focal zone at a focal depth, wherein the cylindrical
transduction element comprises a first surface and a second
surface, wherein the first surface comprises an electrically
conductive coating, wherein the second surface comprises at least
one electrically conductive coated region and at least one region
that is not coated with an electrically conductive coating, wherein
the at least one coated region on the second surface comprises a
conductive material that forms an electrode when the power source
is in electric communication with the at least one coated region,
wherein the at least one coated region on the second surface is
configured to reduce edge noise at the linear focal zone at the
focal depth, wherein the reduction of edge noise reduces a peak
such that a variance around the focal depth is reduced by
75-200%.
59. The ultrasound transduction system according to claim 58,
wherein the first surface is a concave surface and the second
surface is a convex surface.
60. The ultrasound transduction system according to claim 58,
wherein the cylindrical transduction element is housed within an
ultrasonic hand-held probe, wherein the ultrasonic probe comprises:
a housing, the cylindrical transduction element, and a motion
mechanism; wherein the ultrasound transducer is movable within the
housing, wherein the motion mechanism is attached to the ultrasound
transducer and configured to move the ultrasound transducer along a
linear path within the housing.
61. The ultrasound transduction system according to claim 60,
wherein the motion mechanism automatically moves the cylindrical
transduction element to heat a treatment area at the focal depth to
a temperature in a range between 40-65 degrees Celsius.
62. The ultrasound transduction system according to claim 58,
wherein the reduction of edge noise facilitates the production of a
uniform temperature in a treatment area.
63. The ultrasound transduction system according to claim 58,
wherein the power source is configured to drive the cylindrical
transduction element to produce a temperature in a range of 42-55
degrees Celsius in a tissue at the focal depth.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of priority from U.S.
Provisional Application No. 61/981,660 filed Apr. 18, 2014, which
is incorporated in its entirety by reference, herein.
FIELD
[0002] Several embodiments of the present invention generally
relate to noninvasive, semi-invasive, and/or invasive energy-based
treatments to achieve cosmetic and/or medical effects. For example,
some embodiments generally relate to devices, systems and methods
with linear, curved, planar, and/or three-dimensional ultrasound
treatment focus zones for performing various treatment procedures
safely and effectively. Various embodiments of a treatment system
can improve cosmetic results and patient outcomes through reduced
treatment time and/or reduced treatment energy, which can increase
comfort and cosmetic outcomes. In various embodiments, ultrasound
transducers have treatment focus zones in the form of one or more
lines, belts, bands, and/or planes.
DESCRIPTION OF THE RELATED ART
[0003] Many cosmetic procedures involve invasive procedures that
may require invasive surgery, which can places more requirements on
biocompatibility and sterility. Patients not only have to endure
weeks of recovery time, but also are frequently required to undergo
risky anesthetic procedures for aesthetic treatments. Traditional
cosmetic procedures involving piercing or cutting the skin surface
to access target tissue under the skin surface tend to involve
higher requirements on biocompatibility and sterility. Certain
traditional energy based treatments, such as with radio-frequency
(RF) and laser treatments must heat or treat tissue starting from
the skin surface affecting all the intermediary tissue between the
skin surface and a target tissue at a depth under the skin
surface.
SUMMARY
[0004] Although energy-based treatments have been disclosed for
cosmetic and medical purposes, no procedures are known to
Applicant, other that Applicant's own work, that successfully
achieve an aesthetic tissue heating and/or treatment effect using
targeted and precise ultrasound to cause a visible and effective
cosmetic results via a thermal pathway by using band shaped
treatment focus zone techniques to expand the area and volume of
tissue treated at a specific, targeted area. Treatment can include
heating, coagulation, and/or ablation (including, for example,
hyperthermia, thermal dosimetry, apoptosis, and lysis). In various
embodiments, band treatment provides improved thermal heating and
treatment of tissue compared to diathermy or general bulk heating
techniques. In various embodiments, band treatment provides the
capability of heating and/or treating tissue at specific depth
ranges without affecting proximal tissues. In general, diathermy
and bulk heating techniques usually involve heating a skin surface
and conducting the heat through the skin surface and all underlying
tissue to reach a tissue at a target depth below the skin surface.
In various embodiments, band treatment provides targeted heating
and treatment at a specific, prescribed depth range below the skin
surface without heating the skin surface and/or intermediary tissue
between the skin surface and the target tissue. This offset band
treatment reduces damage and associated pain at the skin surface,
and treats tissue only at the prescribed, targeted tissue depth.
Thus, embodiments of the present invention can be used to treat
tissue in a specific range of depths below the skin surface without
heating the skin surface. In some embodiments, band treatment can
also be used to prepare tissue at target depths for a second,
ultrasound treatment by pre-heating the target tissue to an
elevated temperature so the secondary treatment can be performed
with reduced time and/or energy and increased comfort.
[0005] In accordance with various embodiments, a cosmetic
ultrasound treatment system and/or method can non-invasively
produce single or multiple cosmetic treatment zones and/or thermal
treatment points, lines, bands, belts, planes, areas, volumes,
and/or shapes, where ultrasound is focused in one or more locations
in a region of treatment in tissue at one or more depths under a
skin surface. Some systems and methods provide cosmetic treatment
at different locations in tissue, with treatment areas at various
depths, heights, widths, and/or positions. In one embodiment, a
method and system comprise a transducer system configured for
providing ultrasound treatment to more than one region of interest,
such as between at least two treatment positions and/or regions of
interest. In one embodiment, a method and system comprise a
transducer system configured for providing ultrasound treatment to
more than one region of interest, such as between at least two
lines in various locations (e.g. at a fixed or variable depth,
height, width, orientation, etc.) in a region of interest in
tissue. In various embodiments, lines can be straight, curved,
continuous, and/or non-continuous. In some embodiments, the energy
beam is split to focus at two, three, four, or more focal zones
(e.g., multiple focal lines, multi-focal lines) for cosmetic
treatment zones and/or for imaging in a region of interest in
tissue. Position of the focal zones can be positioned axially,
laterally, or otherwise within the tissue. Some embodiments can be
configured for spatial control, such as by the location of a focus
line, changing the distance or angle between a transducer and an
optional motion mechanism, and/or changing the angles of energy
focused or unfocused to the region of interest, and/or configured
for temporal control, such as by controlling changes in the
frequency, drive amplitude and timing of the transducer. In some
embodiments the position of multiple treatment zones can be enabled
through poling, phasic poling, biphasic poling, and/or multi-phasic
poling. As a result, changes in the location of the treatment
region, the number, shape, size and/or volume of treatment zones,
heating zones, and/or lesions in a region of interest, as well as
the thermal conditions, can be dynamically controlled over time.
Additional details regarding poling and modulation are disclosed in
U.S. application Ser. No. 14/193,234 filed on Feb. 28, 2014 and
published as U.S. Publication No. 2014-0257145, which is
incorporated in its entirety by reference herein.
[0006] In one embodiment, an aesthetic imaging and treatment system
includes a hand held probe with a housing that encloses an
ultrasound transducer configured to apply ultrasound therapy to
tissue at a focal zone. In one embodiment, the focal zone is a
line. In one embodiment, the focal zone is a two dimensional region
or plane. In one embodiment, the focal zone is a volume. In various
embodiments, the focal zone treats a treatment area that is linear,
curved, rectangular, and/or planar. In various embodiments, the
size of the treatment area depends on the size of the transducer.
The treatment can be performed in lines and/or planes. In various
embodiments, the width of the treatment focal zone is 5-50 mm, 5-30
mm, 5-25 mm, 10-25 mm, 10 mm-15 mm, 15 mm-20 mm, 10 mm, 15 mm, 20
mm, 25 mm, or any range therein (including but not limited to 12
mm-22 mm). In various embodiments, a focal zone can be moved to
sweep a volume between a first position and a second position. In
various embodiments, one or more a focal zone locations are
positioned in a substantially linear sequence within a cosmetic
treatment zone. In various embodiments, one or more a focal zone
locations are positioned with one, two, or more motion mechanisms
to form any shape for a treatment area within a cosmetic treatment
zone. In one embodiment, a first set of locations is positioned
within a first cosmetic treatment zone and a second set of
locations is positioned within a second cosmetic treatment zone,
the first zone being different from the second zone. In one
embodiment, the first cosmetic treatment zone includes a
substantially linear sequence of the first set of locations and the
second cosmetic treatment zone includes a substantially linear
sequence of the second set of locations. In some non-limiting
embodiments transducers can be configured for a treatment zone at a
tissue depth below a skin surface of 1.5 mm, 3 mm, 4.5 mm, 6 mm,
less than 3 mm, between 1.5 mm and 3 mm, between 1.5 mm and 4.5 mm,
more than more than 4.5 mm, more than 6 mm, and anywhere in the
ranges of 0.1 mm-3 mm, 0.1 mm-4.5 mm, 3 mm-7 mm, 3 mm-9 mm, 0.1
mm-25 mm, 0.1 mm-100 mm, and any depths therein (including, for
example, 4.5 mm-6 mm, 1 mm-20 mm, 1 mm-15 mm, 1 mm-10 mm, 5 mm-25
mm, and any depths therein). In one embodiment, cosmetic treatment
zones are continuous. In one embodiment, cosmetic treatment zones
have no spacing. In one embodiment, a sequence of individual
cosmetic treatment zones with a treatment spacing in a range from
about 0.05 mm to about 25 mm (e.g., 0.05 -0.1 mm, 0.05-1 mm,
0.2-0.5 mm, 0.5-2 mm, 1-10 mm, 0.5-3 mm, 5-12 mm). In various
embodiments, the treatment spacing has a constant pitch, a variable
pitch, an overlapping pitch, and/or a non-overlapping pitch.
[0007] In one embodiment, the ultrasonic transducer is configured
to provide therapeutic intensity on the transducer surface in a
range of between about 1 W/cm.sup.2 to 100 W/cm.sup.2 (e.g., 1-50,
10-90, 25-75, 10-40, 50-80 W/cm.sup.2 and any ranges and values
therein). In one embodiment, the ultrasonic transducer is
configured to provide an acoustic power of the ultrasonic therapy
in a range of between about 1W to about 100 W and a frequency of
about 1 MHz to about 10 MHz to thermally heat the tissue. In
various embodiments, the transducer module is configured to provide
an acoustic power of the ultrasonic therapy in a range of between
about 1 W to about 100 W (e.g., 5-40 W, 10-50 W, 25-35 W, 35-60 W,
35 W, 40 W, 50 W, 60 W) and a frequency of about 1 MHz to about 10
MHz to thermally heat the tissue. In one embodiment, the acoustic
power can be from a range of 1 W to about 100 W in a frequency
range from about 1 MHz to about 12 MHz (e.g., 3.5 MHz, 4 MHz, 4.5
MHz, 7 MHz, 10 MHz, 3-5 MHz), or from about 10 W to about 50 W at a
frequency range from about 3 MHz to about 8 MHz. In one embodiment,
the acoustic power and frequencies are about 40 W at about 4.3 MHz
and about 30 W at about 7.5 MHz. In various embodiments, the
transducer module is configured to deliver energy with no pitch or
a pitch of 0.1-2 mm (e.g., 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1,
1.2, 1.5 mm). In various embodiments, the pitch is constant or
variable. In various embodiments, the transducer module is
configured to deliver energy with an on-time of 10-500 ms (e.g.,
30-100, 90-200, 30, 32, 35, 40, 50, 60, 64, 75, 90, 100, 112, 200,
300, 400 ms and any range therein). In various embodiments, the
transducer module is configured to deliver energy with an off-time
of 1-200 ms (e.g., 4, 10, 22, 45, 60, 90, 100, 150 ms and any range
therein). In one embodiment, an acoustic energy produced by this
acoustic power can be between about 0.01 joule ("J") to about 10 J
or about 2 J to about 5 J. In one embodiment, the acoustic energy
is in a range less than about 3 J. In various embodiments, an
acoustic energy produced by this acoustic power in a single dose
pass can be between about 1-500 J (e.g., 20-310, 70, 100, 120, 140,
150, 160, 200, 250, 300, 350, 400, 450 J and any range therein). In
various embodiments, a treatment can involve 1, 2, 3, 4, 5, 10 or
more dose passes.
[0008] In several embodiments disclosed herein, non-invasive
ultrasound is used to achieve one or more of the following effects:
tissue heating, tissue pre-heating, a face lift, a brow lift, a
chin lift, an eye treatment, a wrinkle reduction, a scar reduction,
a burn treatment, a tattoo removal, a vein removal, a vein
reduction, a treatment on a sweat gland, a treatment of
hyperhidrosis, a fat or adipose and/or cellulite reduction, a sun
spot removal, an acne treatment, a pimple reduction. Treatment of
the decolletage is provided in several embodiments. In another
embodiment the system, device and/or method may be applied in the
genital area (e.g., vaginal rejuvenation and/or vaginal tightening,
such as for tightening the supportive tissue of the vagina). In
several of the embodiments described herein, the procedure is
entirely cosmetic and not a medical act. For example, in one
embodiment, the methods described herein need not be performed by a
doctor, but at a spa or other aesthetic institute. In some
embodiments, a system can be used for the non-invasive cosmetic
treatment of skin.
[0009] In one embodiment, a method of reducing variance in focal
gain of a cylindrical ultrasound transducer includes providing a
cylindrical transduction element comprising a convex surface and a
concave surface, wherein one of the surfaces (e.g., the concave
surface) comprises a plurality of electrodes (or e.g., electrical
conductor or electrical material), and subsequently applying a
current to the electrode, thereby directing ultrasound energy to a
linear focal zone at a focal depth. The ultrasound energy produces
a reduced variance in focal gain at the linear focal zone. The
concave surface can be plated with silver. The convex surface can
include an uncoated region and a plurality of coated regions. The
plurality of coated regions can include fired silver to form the
plurality of electrodes. The features on the convex surface can
instead be on the concave surface.
[0010] In one embodiment, the reduction of edge noise facilitates
the efficient and consistent treatment of tissue, wherein the
cylindrical transduction element is configured to apply ultrasonic
therapy to a linear tissue thermal treatment zone at a focal
depth.
[0011] In one embodiment, the reduction of edge noise facilitates
the efficient and consistent heating of a material, wherein the
material is any one of the group consisting of a compound, an
adhesive, and food.
[0012] In one embodiment, an ultrasound transduction system for
reducing edge noise at a focal line includes a cylindrical
transduction element and a power source configured to drive the
cylindrical transduction element. The cylindrical transduction
element is configured to apply ultrasonic energy to a linear focal
zone at a focal depth. The cylindrical transduction element
includes a convex surface and a concave surface. The concave
surface is plated with an electrical conductor, such as silver. The
convex surface includes an uncoated region and one or more coated
regions, wherein the one or more coated regions includes silver to
form an electrode. The power source is in electric communication
with the electrode. The coated regions are configured to reduce
variance in focal gain at the linear focal zone at the focal
depth.
[0013] In one embodiment, an ultrasound transduction system for
reducing edge noise at a focal line includes a cylindrical
transduction element and a power source configured to drive the
cylindrical transduction element. The cylindrical transduction
element is configured to apply ultrasonic energy to a linear focal
zone at a focal depth. The cylindrical transduction element
includes a convex surface and a concave surface. The convex surface
plated with silver. The concave surface includes an uncoated region
and one or more coated regions, wherein the one or more coated
regions includes silver to form an electrode. The power source is
in electric communication with the electrode. The coated regions
are configured to reduce variance in focal gain at the linear focal
zone at the focal depth.
[0014] In one embodiment, a coated transducer for reducing variance
in focal gain at a focal zone includes a cylindrical transduction
element comprising a convex surface and a concave surface. The
concave surface is plated with silver. The convex surface includes
an uncoated region and a plurality of coated regions. The plurality
of coated regions includes silver to form a plurality of
electrodes. The cylindrical transduction element is configured to
apply ultrasonic therapy to a linear focal zone at a focal depth.
The coated regions are configured to reduce variance in focal gain
at the linear focal zone.
[0015] In one embodiment, a coated transducer for reducing variance
in focal gain at a focal zone includes a cylindrical transduction
element comprising a convex surface and a concave surface. In one
embodiment the convex surface is plated. In one embodiment the
concave surface is plated. In one embodiment the concave surface
includes an uncoated region and a plurality of coated regions. In
one embodiment the convex surface includes an uncoated region and a
plurality of coated regions. The plurality of coated regions
includes a conductor to form a plurality of electrodes. The
cylindrical transduction element is configured to apply ultrasonic
therapy to a linear focal zone at a focal depth. The coated regions
are configured to reduce variance in focal gain at the linear focal
zone.
[0016] In one embodiment, an aesthetic treatment system includes a
cylindrical transduction element comprising a convex surface and a
concave surface. In one embodiment the concave surface is plated
with silver to form an electrode. In one embodiment the convex
surface is plated with silver to form an electrode. In one
embodiment the convex surface includes an uncoated region and one
or more coated regions, wherein the one or more coated regions
includes silver to form an electrode. In one embodiment the concave
surface includes an uncoated region and one or more coated regions,
wherein the one or more coated regions includes silver to form an
electrode. The cylindrical transduction element is configured to
apply ultrasonic therapy to a linear tissue thermal treatment zone
at a focal depth. The coated regions are configured to reduce
variance in focal gain at the thermal treatment zone. The
cylindrical transduction element is housed within an ultrasonic
hand-held probe. In one embodiment, the ultrasonic probe includes a
housing, the cylindrical transduction element, and a motion
mechanism. The ultrasound transducer is movable within the housing.
The motion mechanism is attached to the ultrasound transducer and
configured to move the ultrasound transducer along a linear path
within the housing.
[0017] In one embodiment, an aesthetic imaging and treatment system
includes an ultrasonic probe that includes a housing, a coated
ultrasound transducer, and a motion mechanism. The ultrasound
transducer is movable within the housing, the ultrasound transducer
including a cylindrical transduction element and an imaging
element. The cylindrical transduction element is configured to
apply ultrasonic therapy to a linear tissue thermal treatment zone
at a focal depth. The cylindrical transduction element has an
opening configured for placement of the imaging element. The
cylindrical transduction element includes a convex surface and a
concave surface. In one embodiment, the entire concave surface is
plated with silver. In one embodiment, the entire convex surface is
plated with silver. In one embodiment, the convex surface includes
an uncoated portion and one or more coated regions. In one
embodiment, the concave surface includes an uncoated portion and
one or more coated regions. The coated region includes silver to
form an electrode. The coated regions are configured to reduce
variance in focal gain at the thermal treatment zone. The motion
mechanism is attached to the ultrasound transducer and configured
to move the ultrasound transducer along a linear path within the
housing.
[0018] As provided herein, one of the surfaces of the transduction
element (either the convex or the concave surface) is fully coated
(or at least 90% coated) with an electrically conductive material
(including but not limited to silver or another metal or alloy) and
the other surface (either the convex or the concave surface) has
regions (or a pattern or patchwork) of coated and uncoated portions
that are coated with an electrically conductive material (including
but not limited to silver or another metal or alloy). This, in
several embodiments, can be advantageous because it facilitates
uniform heating (e.g., reducing temperature spikes or
fluctuations). In some embodiments, both surfaces (convex and
concave surfaces) contain regions (or a pattern or patchwork) of
coated and uncoated portions. Although convex and concave surfaces
are described herein, one or both of these surfaces may be planar
in some embodiments. Additionally, convex or concave surfaces as
described herein may be multi-faceted (e.g., with multiple
convexities and/or concavities) and also include surfaces with a
curvature (e.g., one or more angles less than 180 degrees). In
several embodiments, the pattern of coated and uncoated regions can
include one, two or more coated regions and one, two or more
uncoated regions, wherein the coated regions cover at least 60%,
70%, 80%, or 90% of the surfaces. Further, the uncoated region may
be considered uncoated to the extent it does not have an
electrically conductive coating--the uncoated region may have other
types of surface coatings in certain embodiments.
[0019] In various embodiments, an ultrasound system includes a
transducer with a transduction element (e.g., a flat, round,
circular, cylindrical, annular, have rings, concave, convex,
contoured or other shaped transduction element).
[0020] In various embodiments, an ultrasound transduction system,
includes a transduction element (e.g., a cylindrical transduction
element), and a power source configured to drive the transduction
element, wherein the transduction element is configured to apply
ultrasonic energy to a linear focal zone at a focal depth, wherein
the transduction element comprises a first surface and a second
surface, wherein the first surface comprises an electrically
conductive coating, wherein the second surface comprises at least
one electrically conductive coated region and at least one uncoated
region that is not coated with an electrically conductive coating,
wherein the at least one coated region on the second surface
comprises a conductive material that forms an electrode when the
power source is in electric communication with the at least one
coated region, wherein the at least one coated region on the second
surface is configured to reduce edge noise at the linear focal zone
at the focal depth.
[0021] In various embodiments, an ultrasound transduction system
includes a cylindrical transduction element and a power source
configured to drive the cylindrical transduction element, wherein
the cylindrical transduction element is configured to apply
ultrasonic energy to a linear focal zone at a focal depth. In some
embodiments, the cylindrical transduction element comprises a first
surface and a second surface, wherein the first surface comprises a
coating, wherein the second surface comprises at least one coated
region and at least one uncoated region, wherein the at least one
coated region on the second surface comprises a conductive material
that forms an electrode when the power source is in electric
communication with the at least one coated region, wherein the at
least one coated region on the second surface is configured to
reduce edge noise at the linear focal zone at the focal depth.
[0022] In an embodiment, the uncoated region does not comprise a
conductive material. In an embodiment, the conductive material is a
metal (e.g., silver, gold, platinum, mercury, and/or copper, or an
alloy). In an embodiment, the first surface is a concave surface
and the second surface is a convex surface. In an embodiment, the
first surface is a convex surface and the second surface is a
concave surface. In an embodiment, the cylindrical transduction
element is housed within an ultrasonic hand-held probe, wherein the
ultrasonic probe includes a housing, the cylindrical transduction
element, and a motion mechanism, wherein the ultrasound transducer
is movable within the housing, wherein the motion mechanism is
attached to the ultrasound transducer and configured to move the
ultrasound transducer along a linear path within the housing. In an
embodiment, the motion mechanism automatically moves the
cylindrical transduction element to heat a treatment area at the
focal depth to a temperature in a range between 40-65 degrees
Celsius (e.g., 40-45, 40-50, 40-55, 45-60, 45-55, 45-50 degrees
Celsius, and any values therein). In an embodiment, the reduction
of edge noise facilitates the production of a uniform (e.g.,
completely uniform, substantially uniform, about uniform)
temperature in a treatment area. In an embodiment, the reduction of
edge noise facilitates the efficient and consistent treatment of a
tissue, wherein the cylindrical transduction element is configured
to apply ultrasonic therapy to a treatment zone at the focal depth
in the tissue. In an embodiment, the reduction of edge noise
reduces a peak such that a variance around the focal depth is
reduced by 75-200% (e.g., 75-100, 80-150, 100-150, 95-175%, and any
values therein). In an embodiment, the reduction of edge noise
reduces a peak such that a variance of an intensity around the
focal depth is 5 mm or less (e.g., 4.5, 4, 3.5, 3, 2.5, 2, 1.5, 1,
0.5 or less). In an embodiment, the reduction of edge noise reduces
a variance in focal gain in a range of 0.01-10 (e.g., 1-5, 2-8,
0.5-3, and any any values therein). In an embodiment, the power
source is configured to drive the cylindrical transduction element
to produce a temperature in a range of 42-55 degrees Celsius (e.g.,
43-48, 45-53, 45-50 degrees Celsius, and any values therein) in a
tissue at the focal depth. In an embodiment, a temperature sensor
is located on the housing proximate an acoustic window in the
housing configured to measure a temperature at a skin surface. In
an embodiment, a system includes one or more imaging elements,
wherein the cylindrical transduction element has an opening
configured for placement of the one or more imaging elements. In an
embodiment, the imaging element is configured to confirm a level of
acoustic coupling between the system and a skin surface. In an
embodiment, the imaging element is configured to confirm a level of
acoustic coupling between the system and a skin surface via any one
of the group consisting of: defocused imaging and Voltage Standing
Wave Ratio (VSWR). In an embodiment, the imaging element is
configured to measure a temperature at a target tissue at the focal
depth below a skin surface. In an embodiment, the imaging element
is configured to measure a temperature at a target tissue at the
focal depth below a skin surface with any one of the group of
Acoustic Radiation Force Impulse (ARFI), Shear Wave Elasticity
Imaging (SWEI), and measurement of attenuation.
[0023] In several embodiments, a method of heating tissue with a
cylindrical ultrasound transducer includes providing a cylindrical
transduction element comprising a first surface, a second surface,
a coated region, and an uncoated region. In some embodiments, the
coated region comprises an electrical conductor. In some
embodiments, the uncoated region does not comprise an electrical
conductor. In some embodiments, the first surface comprises at
least one coated region, wherein the second surface comprises the
uncoated region and a plurality of coated regions, applying a
current to the coated region, thereby directing ultrasound energy
to a linear focal zone at a focal depth, wherein the ultrasound
energy produces a reduction in focal gain at the linear focal
zone.
[0024] In several embodiments, a cosmetic method of non-invasively
and non-ablatively heating tissue with a heating source (e.g., a
cylindrical ultrasound transducer) to heat the region under a
subject's skin by between 5-25 degrees Celsius) while causing the
temperature at the skin surface to stay the same or increases to a
temperature that does not causing discomfort (e.g., by 1-5, 1-10,
1-15 degrees Celsius). This differential aids in the comfort of the
subject. The heating, in one embodiment, occurs in increments over
a period of 5-120 minutes with a graded or gradual increase in
temperature. The heating can be performed by the cylindrical
ultrasound transducer systems described herein. Optionally, an
ablative or coagulative energy can subsequently be applied by
increasing the temperature by another 5-25 degrees Celsius. The
initial pre-heating step or bulk heating is advantageous because it
allows less energy to be applied to achieve the
coagulative/ablative state. In one embodiment, the initial
pre-heating step is performed with a heating source other than an
ultrasound transducer. For example, radiofrequency, microwave,
light, convective, conversion, and/or conductive heat sources can
be used instead of or in addition to ultrasound.
[0025] In several embodiments, a non-invasive, cosmetic method of
heating tissue includes applying a cosmetic heating system to a
skin surface, wherein the cosmetic heating system comprises a
hand-held probe. In some embodiments, the hand-held probe comprises
a housing that encloses an ultrasound transducer configured to heat
tissue below the skin surface to a tissue temperature in the range
of 40-50 degrees Celsius (e.g., 44-47, 41-49, 45-50 degrees
Celsius, and any values therein). In some embodiments, the
ultrasound transducer comprises a cylindrical transduction element
comprising a first surface, a second surface, a coated region, and
an uncoated region, wherein the coated region comprises an
electrical conductor, wherein the first surface comprises at least
one coated region, wherein the second surface comprises the
uncoated region and a plurality of coated regions. In some
embodiments, the method includes applying a current to the
plurality of coated regions, thereby directing ultrasound energy to
a linear focal zone at a focal depth, wherein the ultrasound energy
produces a reduction in focal gain at the linear focal zone,
thereby heating the tissue at the focal depth in the linear focal
zone to the tissue temperature in the range of 40-50 degrees
Celsius for a cosmetic treatment duration of less than 1 hour
(e.g., 1-55, 10-30, 5-45, 15-35, 20-40 minutes and any values
therein), thereby reducing a volume of an adipose tissue in the
tissue.
[0026] In an embodiment, the reduction of focal gain facilitates
the efficient and consistent treatment of tissue, wherein the
cylindrical transduction element is configured to apply ultrasonic
therapy to a thermal treatment zone at a focal depth. In an
embodiment, the reduction of focal gain reduces a peak such that a
variance around the focal depth is reduced by 25-100% (e.g., 30-50,
45-75, 50-90%, and any values therein). In an embodiment, the
reduction of focal gain reduces a peak such that a variance of an
intensity around the focal depth is 5 mm or less (e.g., 1, 2, 3, 4
mm or less). In an embodiment, the reduction of focal gain reduces
a variance in focal gain in a range of 0.01-10 (e.g., 0.06, 3, 4.5,
8, or any values therein). In an embodiment, the electrical
conductor is a metal. In an embodiment, the first surface is a
concave surface and the second surface is a convex surface. In an
embodiment, the first surface is a convex surface and the second
surface is a concave surface. In an embodiment, the cylindrical
transduction element is housed within an ultrasonic hand-held
probe, wherein the ultrasonic probe includes a housing, the
cylindrical transduction element, and a motion mechanism, wherein
the ultrasound transducer is movable within the housing, wherein
the motion mechanism is attached to the ultrasound transducer and
configured to move the ultrasound transducer along a linear path
within the housing. In an embodiment, the motion mechanism
automatically moves the cylindrical transduction element to heat a
treatment area at the focal depth to a temperature in a range
between 40-65 degrees Celsius. In an embodiment, the cylindrical
transduction element produces a temperature in a range of 42-55
degrees Celsius in a tissue at the focal depth. In an embodiment,
the method also includes imaging tissue with one or more imaging
elements, wherein the cylindrical transduction element has an
opening configured for placement of the one or more imaging
elements. In an embodiment, the method also includes confirming a
level of acoustic coupling between the system and a skin surface
with an image from the imaging element. In an embodiment, the
method also includes confirming a level of acoustic coupling
between the system and a skin surface with the imaging element
using any one of the group consisting of: defocused imaging and
Voltage Standing Wave Ratio (VSWR). In an embodiment, the method
also includes measuring a temperature at a target tissue at the
focal depth below a skin surface with the imaging element. In an
embodiment, the method also includes measuring a temperature with
the imaging element at a target tissue at the focal depth below a
skin surface with any one of the group of Acoustic Radiation Force
Impulse (ARFI), Shear Wave Elasticity Imaging (SWEI), and
measurement of attenuation.
[0027] The methods summarized above and set forth in further detail
below describe certain actions taken by a practitioner; however, it
should be understood that they can also include the instruction of
those actions by another party. Thus, actions such as "applying an
ultrasound energy" include "instructing the application of
ultrasound energy."
[0028] Further, areas of applicability will become apparent from
the description provided herein. It should be understood that the
description and specific examples are intended for purposes of
illustration only and are not intended to limit the scope of the
embodiments disclosed herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] The drawings described herein are for illustration purposes
only and are not intended to limit the scope of the present
disclosure in any way. Embodiments of the present invention will
become more fully understood from the detailed description and the
accompanying drawings wherein:
[0030] FIG. 1 is a schematic illustration of an ultrasound system
according to various embodiments of the present invention.
[0031] FIG. 2 is a schematic illustration of an ultrasound system
coupled to a region of interest according to various embodiments of
the present invention.
[0032] FIG. 3 illustrates a schematic cross-sectional side view of
a cylindrical transducer in a cosmetic treatment system according
to an embodiment. Although a cylinder transducer is illustrated
here, the transducer need not be cylindrical. In several
embodiments, the transducer has one or more shapes or
configurations that cause edge effects, such as variance, spikes or
other inconsistencies in the delivery of ultrasound. For example,
the transducer may have one or more non-linear (e.g., curved)
portions.
[0033] FIG. 4 illustrates a schematic isometric side view of a
sectioned cylindrical transducer of FIG. 3;
[0034] FIGS. 5A-5B illustrate a schematic isometric side view of a
cylindrical transducer being moved by a motion mechanism in a
cosmetic treatment system, wherein the thermal treatment zone (TTZ)
sweeps a treatment area, according to an embodiment.
[0035] FIG. 6 illustrates a schematic exploded isometric view of a
cylindrical transduction element in a cosmetic treatment system
according to an embodiment.
[0036] FIG. 7 illustrates a schematic isometric view of the
cylindrical transduction element of FIG. 6 with a motion mechanism
in a cosmetic treatment system according to an embodiment.
[0037] FIG. 8 illustrates a schematic isometric view of the
cylindrical transduction element with a motion mechanism of FIG. 7
in a probe housing of a cosmetic treatment system according to an
embodiment.
[0038] FIG. 9 is a schematic partial cut away illustration of a
portion of a transducer according to various embodiments of the
present invention.
[0039] FIG. 10 is a partial cut away side view of an ultrasound
system according to various embodiments of the present
invention.
[0040] FIGS. 11A-11B are schematic illustrations and plots
illustrating normalized pressure intensity distributions at a depth
of 20 mm according to an embodiment of a transducer comprising a
cylindrical transduction element.
[0041] FIGS. 12A-12B are schematic illustrations and plots
illustrating normalized pressure intensity distributions at a depth
of 15 mm according to the embodiment of a transducer comprising a
cylindrical transduction element of FIG. 11A-11B.
[0042] FIGS. 13A-13B are schematic illustrations and plots
illustrating normalized pressure intensity distributions at a depth
of 13 mm according to the embodiment of a transducer comprising a
cylindrical transduction element of FIG. 11A-11B.
[0043] FIGS. 14A-14B are schematic plots illustrating normalized
pressure intensity distributions at a depth of 20 mm according to
an embodiment of a transducer comprising a cylindrical transduction
element.
[0044] FIGS. 15A-15B are schematic plots illustrating normalized
pressure intensity distributions at a depth of 15 mm according to
the embodiment of a transducer comprising a cylindrical
transduction element of FIG. 11A-11B.
[0045] FIGS. 16A-16B are schematic plots illustrating normalized
pressure intensity distributions at a depth of 13 mm according to
the embodiment of a transducer comprising a cylindrical
transduction element of FIG. 11A-11B.
[0046] FIG. 17 is a plot illustrating temperature in porcine muscle
over time at different power levels for an embodiment of a
transducer comprising a cylindrical transduction element.
[0047] FIG. 18 is a photograph of porcine muscle after experimental
treatment confirming confirmed line and plane heating with an
embodiment of a transducer comprising a cylindrical transduction
element.
[0048] FIG. 19 is a cross-section cut through the porcine muscle in
FIG. 18 showing a linear thermal treatment zone.
[0049] FIG. 20 is an orthogonal cross-section cut through the
porcine muscle in FIG. 19 showing a planar thermal treatment
zone.
[0050] FIG. 21 is a cross-section view of a combined imaging and
cylindrical therapy transducer according to an embodiment of the
present invention.
[0051] FIG. 22 is a side view of a combined imaging and cylindrical
therapy transducer according to FIG. 21.
[0052] FIG. 23 is a plot illustrating harmonic pressure across an
azimuth of an embodiment of a cylindrical element with an imaging
element.
[0053] FIG. 24 is a plot illustrating harmonic pressure across an
azimuth of an embodiment of a coated cylindrical element with an
imaging element.
[0054] FIG. 25 is a plot illustrating harmonic pressure across an
azimuth of an embodiment of a cylindrical element with an imaging
element compared to an embodiment of a coated cylindrical element
with an imaging element.
[0055] FIG. 26 is a side view of a coated transducer comprising a
cylindrical transduction element with one or more coated regions
according to an embodiment of the present invention.
[0056] FIG. 27 is a plot illustrating focal gain across the azimuth
of two embodiments of cylindrical transduction elements.
[0057] FIG. 28 is a schematic plot illustrating normalized pressure
intensity distributions at a depth distal to the focal zone by
about 5 mm according to an embodiment of a coated transducer
comprising a cylindrical transduction element with one or more
coated regions.
[0058] FIG. 29 is a schematic plot illustrating normalized pressure
intensity distributions at a focal depth according to the
embodiment of the coated transducer of FIG. 28.
[0059] FIG. 30 is a schematic plot illustrating normalized pressure
intensity distributions at a depth proximal to the focal depth by
about 2 mm according to the embodiment of the coated transducer of
FIG. 28.
[0060] FIG. 31 is a side view of a coated transducer according to
an embodiment of the present invention.
[0061] FIG. 32 is a side view of a coated transducer according to
an embodiment of the present invention.
[0062] FIG. 33 is a side view of a coated transducer according to
an embodiment of the present invention.
[0063] FIG. 34 is a side view of a coated transducer according to
an embodiment of the present invention.
[0064] FIG. 35 is a side view of a coated transducer according to
an embodiment of the present invention.
[0065] FIG. 36 is a side view of a coated transducer according to
an embodiment of the present invention.
[0066] FIG. 37 is a side view of a coated transducer according to
an embodiment of the present invention.
[0067] FIG. 38 is a side view of a coated transducer according to
an embodiment of the present invention.
[0068] FIG. 39 illustrates a charts relating time and temperature
to attain various theoretical cell kill fractions according to an
embodiment of the present invention.
[0069] FIG. 40 illustrates charts relating time and temperature to
attain various theoretical cell kill fractions according to an
embodiment of the present invention.
[0070] FIG. 41 is a table listing isoeffective dosages to
theoretically achieve 1% survival fraction in tissue, listing
temperature and time, according to an embodiment of the present
invention.
[0071] FIG. 42 is a chart relating time and temperature for
isoeffective doses applied for surviving fraction of cells
according to an embodiment of the present invention.
[0072] FIG. 43 illustrates simulations of cylindrical transducer
output showing linear superposition of multiple pulses according to
an embodiment of the present invention.
[0073] FIG. 44 is a top view of an apodized transducer according to
an embodiment of the present invention.
[0074] FIG. 45 illustrates acoustic pressure profiles with an
apodized transducer according to the embodiment of FIG. 44.
[0075] FIG. 46 is a chart illustrating temperature profiles from an
embodiment of an in-vivo porcine model treatment dosage study
according to an embodiment of the present invention.
[0076] FIG. 47 is a chart for setting for an isoeffective dosage
study according to an embodiment of the present invention.
[0077] FIG. 48 illustrates cumulative dose relating time,
temperature, and pass count of a treatment study according to an
embodiment of the present invention.
[0078] FIG. 49 is a table with target temperatures and time for a
treatment study according to an embodiment of the present
invention.
[0079] FIG. 50 is a table with various embodiments of transducers
treatments settings for an isoeffective thermal dosage treatment
study according to an embodiment of the present invention.
[0080] FIG. 51 is an image of a thermally overdosed site with a
transducer according to an embodiment of the present invention.
[0081] FIG. 52 is chart relating time and temperature with target
goal temperatures according to an embodiment of the present
invention.
[0082] FIG. 53 is an isometric side view of a transducer and
treatment area according to an embodiment of the present
invention.
[0083] FIG. 54 is a chart illustrating velocity and position along
an axis according to an embodiment of the present invention.
[0084] FIG. 55 is a chart illustrating velocity and position along
an axis according to an embodiment of the present invention.
[0085] FIG. 56 is a chart illustrating amplitude and position along
an axis according to an embodiment of the present invention.
[0086] FIG. 57 is a chart illustrating velocity and position along
an axis according to an embodiment of the present invention.
[0087] FIG. 58 is a chart illustrating velocity and position along
an axis according to an embodiment of the present invention.
[0088] FIG. 59 illustrates a non-overlapping treatment according to
an embodiment of the present invention.
[0089] FIG. 60 illustrates a partially overlapping and a partially
non-overlapping treatment according to an embodiment of the present
invention.
[0090] FIG. 61 illustrates a treatment area according to various
embodiments of the present invention.
[0091] FIG. 62 is a chart illustrating intensity and depth
according to an embodiment of the present invention.
[0092] FIG. 63 is an isometric side view of a transducer and
treatment area with multiple thermal treatment zones according to
an embodiment of the present invention.
[0093] FIG. 64 is a schematic side view of a system comprising a
plurality of ultrasound elements on a motion mechanism according to
an embodiment of the present invention.
DETAILED DESCRIPTION
[0094] The following description sets forth examples of
embodiments, and is not intended to limit the present invention or
its teachings, applications, or uses thereof. It should be
understood that throughout the drawings, corresponding reference
numerals indicate like or corresponding parts and features. The
description of specific examples indicated in various embodiments
of the present invention are intended for purposes of illustration
only and are not intended to limit the scope of the invention
disclosed herein. Moreover, recitation of multiple embodiments
having stated features is not intended to exclude other embodiments
having additional features or other embodiments incorporating
different combinations of the stated features. Further, features in
one embodiment (such as in one figure) may be combined with
descriptions (and figures) of other embodiments.
[0095] In various embodiments, systems and methods for ultrasound
treatment of tissue are configured to provide cosmetic treatment.
Various embodiments of the present invention address potential
challenges posed by administration of ultrasound therapy. In
various embodiments, the amount of time and/or energy to create a
thermal treatment zone (also referred to herein "TTZ") for a
desired cosmetic and/or therapeutic treatment for a desired
clinical approach at a target tissue is reduced. In various
embodiments, tissue below or at a skin surface such as epidermis,
dermis, platysma, lymph node, nerve, fascia, muscle, fat, and/or
superficial muscular aponeurotic system ("SMAS"), are treated
non-invasively with ultrasound energy. In various embodiments,
tissue below or at a skin surface such as epidermis, dermis,
platysma, lymph node, nerve, fascia, muscle, fat, and/or SMAS are
not treated. The ultrasound energy can be focused at one or more
treatment zones, can be unfocused and/or defocused, and can be
applied to a region of interest to achieve a cosmetic and/or
therapeutic effect. In various embodiments, systems and/or methods
provide non-invasive dermatological treatment to tissue through
heating, thermal treatment, coagulation, ablation, and/or tissue
tightening (including, for example, hyperthermia, thermal
dosimetry, apoptosis, and lysis). In one embodiment, dermal tissue
volume is increased. In one embodiment, fat tissue volume is
reduced, or decreased.
[0096] In various embodiments, target tissue is, but is not limited
to, any of skin, eyelids, eye lash, eye brow, caruncula lacrimalis,
crow's feet, wrinkles, eye, nose, mouth, tongue, teeth, gums, ears,
brain, chest, back, buttocks, legs, arms, hands, arm pits, heart,
lungs, ribs, abdomen, stomach, liver, kidneys, uterus, breast,
vagina, penis, prostate, testicles, glands, thyroid glands,
internal organs, hair, muscle, bone, ligaments, cartilage, fat, fat
lobuli, adipose tissue, cellulite, subcutaneous tissue, implanted
tissue, an implanted organ, lymphoid, a tumor, a cyst, an abscess,
or a portion of a nerve, or any combination thereof. In several
embodiments disclosed herein, non-invasive ultrasound is used to
achieve one or more of the following effects: a face lift, a brow
lift, a chin lift, an eye treatment, a wrinkle reduction, a scar
reduction, a fat reduction, a reduction in the appearance of
cellulite, a decolletage treatment, a burn treatment, a tattoo
removal, a vein reduction, a treatment on a sweat gland, a
treatment of hyperhidrosis, sun spot removal, an acne treatment,
and a pimple removal. In some embodiments, two, three or more
beneficial effects are achieved during the same treatment session,
and may be achieved simultaneously.
[0097] Various embodiments of the present invention relate to
devices or methods of controlling the delivery of energy to tissue.
In various embodiments, various forms of energy can include
acoustic, ultrasound, light, laser, radio-frequency (RF),
microwave, electromagnetic, radiation, thermal, cryogenic, electron
beam, photon-based, magnetic, magnetic resonance, and/or other
energy forms. Various embodiments of the present invention relate
to devices or methods of splitting an ultrasonic energy beam into
multiple beams. In various embodiments, devices or methods can be
used to alter the delivery of ultrasound acoustic energy in any
procedures such as, but not limited to, therapeutic ultrasound,
diagnostic ultrasound, non-destructive testing (NDT) using
ultrasound, ultrasonic welding, any application that involves
coupling mechanical waves to an object, and other procedures.
Generally, with therapeutic ultrasound, a tissue effect is achieved
by concentrating the acoustic energy using focusing techniques from
the aperture. In some instances, high intensity focused ultrasound
(HIFU) is used for therapeutic purposes in this manner In one
embodiment, a tissue effect created by application of therapeutic
ultrasound at a particular location (e.g., depth, width) to can be
referred to as creation of a thermal treatment zone. It is through
creation of thermal treatment zones at particular positions that
thermal and/or mechanical heating, coagulation, and/or ablation of
tissue can occur non-invasively or remotely offset from the skin
surface.
System Overview
[0098] Various embodiments of ultrasound treatment and/or imaging
devices are described in U.S. Publication No. 2011-0112405, which
is a national phase publication from International Publication WO
2009/149390, each of which is incorporated in its entirety by
reference herein.
[0099] With reference to the illustration in FIG. 1, an embodiment
of an ultrasound system 20 includes a hand wand 100, module 200,
and a controller 300. The hand wand 100 can be coupled to the
controller 300 by an interface 130, which may be a wired or
wireless interface. The interface 130 can be coupled to the hand
wand 100 by a connector 145. The distal end of the interface 130
can be connected to a controller connector on a circuit 345. In one
embodiment, the interface 130 can transmit controllable power from
the controller 300 to the hand wand 100. In various embodiments,
the controller 300 can be configured for operation with the hand
wand 100 and the module 200, as well as the overall ultrasound
system 20 functionality. In various embodiments, a controller 300
is configured for operation with a hand wand 100 with one or more
removable modules 200, 200', 200'', etc. The controller 300 can
include an interactive graphical display 310, which can include a
touchscreen monitor and Graphic User Interface (GUI) that allows
the user to interact with the ultrasound system 20. As is
illustrated, the graphical display 315 includes a touchscreen
interface 315. In various embodiments, the display 310 sets and
displays the operating conditions, including equipment activation
status, treatment parameters, system messages and prompts, and
ultrasound images. In various embodiments, the controller 300 can
be configured to include, for example, a microprocessor with
software and input/output devices, systems and devices for
controlling electronic and/or mechanical scanning and/or
multiplexing of transducers and/or multiplexing of transducer
modules, a system for power delivery, systems for monitoring,
systems for sensing the spatial position of the probe and/or
transducers and/or multiplexing of transducer modules, and/or
systems for handling user input and recording treatment results,
among others. In various embodiments, the controller 300 can
include a system processor and various analog and/or digital
control logic, such as one or more of microcontrollers,
microprocessors, field-programmable gate arrays, computer boards,
and associated components, including firmware and control software,
which may be capable of interfacing with user controls and
interfacing circuits as well as input/output circuits and systems
for communications, displays, interfacing, storage, documentation,
and other useful functions. System software running on the system
process may be configured to control all initialization, timing,
level setting, monitoring, safety monitoring, and all other
ultrasound system functions for accomplishing user-defined
treatment objectives. Further, the controller 300 can include
various input/output modules, such as switches, buttons, etc., that
may also be suitably configured to control operation of the
ultrasound system 20. In one embodiment, the controller 300 can
include one or more data ports 390. In various embodiments, the
data ports 390 can be a USB port, Bluetooth port, IrDA port,
parallel port, serial port, and the like. The data ports 390 can be
located on the front, side, and/or back of the controller 300, and
can be used for accessing storage devices, printing devices,
computing devices, etc. The ultrasound system 20 can include a lock
395. In one embodiment, in order to operate the ultrasound system
20, the lock 395 should be unlocked so that a power switch 393 may
be activated. In one embodiment, the lock 395 can be connectable to
the controller 300 via a data port 390 (e.g., a USB port). The lock
395 could be unlocked by inserting into the data port 390 an access
key (e.g., USB access key), a hardware dongle, or the like. The
controller 300 can include an emergency stop button 392, which can
be readily accessible for emergency deactivation.
[0100] As is illustrated in FIG. 1, in one embodiment, the hand
wand 100 includes one or more finger activated controllers or
switches, such as 150 and 160. In one embodiment, the hand wand 100
can include a removable module 200. In other embodiments, the
module 200 may be non-removable. The module 200 can be mechanically
coupled to the hand wand 100 using a latch or coupler 140. An
interface guide 235 can be used for assisting the coupling of the
module 200 to the hand wand 100. The module 200 can include one or
more ultrasound transducers 280. In some embodiments, an ultrasound
transducer 280 includes one or more ultrasound elements 281. The
module 200 can include one or more ultrasound elements 281. The
elements 281 can be therapy elements, and/or imaging elements. The
hand wand 100 can include imaging-only modules 200, treatment-only
modules 200, imaging-and-treatment modules 200, and the like. In
one embodiment, the imaging is provided through the hand wand 100.
In one embodiment, the control module 300 can be coupled to the
hand wand 100 via the interface 130, and the graphic user interface
310 can be configured for controlling the module 200. In one
embodiment, the control module 300 can provide power to the hand
wand 100. In one embodiment, the hand wand 100 can include a power
source. In one embodiment, the switch 150 can be configured for
controlling a tissue imaging function and the switch 160 can be
configured for controlling a tissue treatment function
[0101] In one embodiment, the module 200 can be coupled to the hand
wand 100. The module 200 can emit and receive energy, such as
ultrasonic energy. The module 200 can be electronically coupled to
the hand wand 100 and such coupling may include an interface which
is in communication with the controller 300. In one embodiment, the
interface guide 235 can be configured to provide electronic
communication between the module 200 and the hand wand 100. The
module 200 can comprise various probe and/or transducer
configurations. For example, the module 200 can be configured for a
combined dual-mode imaging/therapy transducer, coupled or co-housed
imaging/therapy transducers, separate therapy and imaging probes,
and the like. In one embodiment, when the module 200 is inserted
into or connected to the hand wand 100, the controller 300
automatically detects it and updates the interactive graphical
display 310.
[0102] In various embodiments, tissue below or even at a skin
surface such as epidermis, dermis, hypodermis, fascia, and SMAS,
and/or muscle are treated non-invasively with ultrasound energy.
Tissue may also include blood vessels and/or nerves. The ultrasound
energy can be focused, unfocused or defocused and applied to a
region of interest containing at least one of epidermis, dermis,
hypodermis, fascia, and SMAS to achieve a therapeutic effect. FIG.
2 is a schematic illustration of the ultrasound system 20 coupled
to a region of interest 10, such as with an acoustic gel. With
reference to the illustration in FIG. 2, an embodiment of the
ultrasound system 20 includes the hand wand 100, the module 200,
and the controller 300. In various embodiments, tissue layers of
the region of interest 10 can be at any part of the body of a
subject. In various embodiments, the tissue layers are in the head,
face, neck and/or body region of the subject. The cross-sectional
portion of the tissue of the region of interest 10 includes a skin
surface 501, an epidermal layer 502, a dermal layer 503, a fat
layer 505, a SMAS 507, and a muscle layer 509. The tissue can also
include the hypodermis 504, which can include any tissue below the
dermal layer 503. The combination of these layers in total may be
known as subcutaneous tissue 510. Also illustrated in FIG. 2 is a
treatment zone 525 which is the active treatment area below the
surface 501. In one embodiment, the surface 501 can be a surface of
the skin of a subject 500. Although an embodiment directed to
therapy at a tissue layer may be used herein as an example, the
system can be applied to any tissue in the body. In various
embodiments, the system and/or methods may be used on muscles (or
other tissue) of the face, neck, head, arms, legs, or any other
location in the body. In various embodiments, the therapy can be
applied to a face, head, neck, submental region, shoulder, arm,
back, chest, buttock, abdomen, stomach, waist, flank, leg, thigh,
or any other location in or on the body.
Band Therapy Using A Cylindrical Transducer
[0103] In various embodiments, a transducer 280 can comprise one or
more therapy elements 281 that can have various shapes that
correspond to various focal zone geometries. In one embodiment, the
transducer 280 comprises a single therapy element 281. In one
embodiment, the transducer 280 does not have a plurality of
elements. In one embodiment, the transducer 280 does not have an
array of elements. In several embodiments, the transducers 280
and/or therapy elements 281 described herein can be flat, round,
circular, cylindrical, annular, have rings, concave, convex,
contoured, and/or have any shape. In some embodiments, the
transducers 280 and/or therapy elements 281 described herein are
not flat, round, circular, cylindrical, annular, have rings,
concave, convex, and/or contoured. In one embodiment, the
transducers 280 and/or therapy elements 281 have a mechanical
focus. In one embodiment, the transducers 280 and/or therapy
elements 281 do not have a mechanical focus. In one embodiment, the
transducers 280 and/or therapy elements 281 have an electrical
focus. In one embodiment, the transducers 280 and/or therapy
elements 281 do not have an electrical focus. Although a cylinder
transducer and/or a cylindrical element is discussed here, the
transducer and/or element need not be cylindrical. In several
embodiments, the transducer and/or element has one or more shapes
or configurations that cause edge effects, such as variance, spikes
or other inconsistencies in the delivery of ultrasound. For
example, the transducer and/or element may have one or more
non-linear (e.g., curved) portions. A transducer may be comprised
of one or more individual transducers and/or elements in any
combination of focused, planar, or unfocused single-element,
multi-element, element, or array transducers, including 1-D, 2-D,
and annular arrays; linear, curvilinear, sector, or spherical
arrays; spherically, cylindrically, and/or electronically focused,
defocused, and/or lensed sources. In one embodiment, the transducer
is not a multi-element transducer. In one embodiment, a transducer
280 can include a spherically shaped bowl with a diameter and one
or more concave surfaces (with respective radii or diameters)
geometrically focused to a single point TTZ 550 at a focal depth
278 below a tissue surface, such as skin surface 501. In one
embodiment, a transducer 280 may be radially symmetrical in three
dimensions. For example, in one embodiment, transducer 280 may be a
radially symmetrical bowl that is configured to produce a focus
point in a single point in space. In some embodiments, the
transducer is not spherically shaped. In some embodiments, the
element is not spherically shaped.
[0104] In various embodiments, increasing the size (e.g. width,
depth, area) and/or number of focus zone locations for an
ultrasonic procedure can be advantageous because it permits
treatment of a patient at varied tissue widths, heights and/or
depths even if the focal depth 278 of a transducer 280 is fixed.
This can provide synergistic results and maximizing the clinical
results of a single treatment session. For example, treatment at
larger treatment areas under a single surface region permits a
larger overall volume of tissue treatment, which can heat larger
tissue volumes, and which can result in enhanced collagen formation
and tightening. Additionally, larger treatment areas, such as at
different depths, affects different types of tissue, thereby
producing different clinical effects that together provide an
enhanced overall cosmetic result. For example, superficial
treatment may reduce the visibility of wrinkles and deeper
treatment may induce skin tightening and/or collagen growth.
Likewise, treatment at various locations at the same or different
depths can improve a treatment. In various embodiments, a larger
treatment area can be accomplished using a transducer with a larger
focus zones (e.g., such as a linear focus zone compared to a point
focus zone).
[0105] In one embodiment, as illustrated in FIGS. 3 and 4, a
transducer 280 comprises a cylindrical transduction element 281. In
FIG. 4, the view of the cylindrical transduction element 281, which
has a concave surface 282 and a convex surface 283, is sectioned to
show energy emission from the concave surface to a linear TTZ 550.
The cylindrical transduction element 281 extends linearly along its
longitudinal axis (X-axis, azimuth) with a curved cross section
along a Y-axis (elevation). In one embodiment, the cylindrical
surface has a radius at a focal depth (z-axis) at the center of the
curvature of the cylindrical surface, such that the TTZ 550 is
focused at the center of the radius. For example, in one
embodiment, cylindrical transduction element 281 has a concave
surface that extends like a cylinder that produces a focus zone
that extends along a line, such as a therapy line, such as TTZ 550.
The focus zone TTZ 550 extends along the width (along the X-axis,
azimuth) of the cylindrical transduction element 281, in a line
parallel to the longitudinal axis of the cylindrical transduction
element 281. As illustrated in FIG. 3, the TTZ 550 is a line
extending in and/or out of the page. In various embodiments of the
cylindrical transduction element 281, a concave surface directs
ultrasound energy to a linear TTZ 550. Cylindrical transduction
element 281 need not be cylindrical; in some embodiments, element
281 is a transduction element having one or more curved or
non-linear portions.
[0106] In various embodiments, transducers 280 can comprise one or
more transduction elements 281. The transduction elements 281 can
comprise a piezoelectrically active material, such as lead
zirconante titanate (PZT), or any other piezoelectrically active
material, such as a piezoelectric ceramic, crystal, plastic, and/or
composite materials, as well as lithium niobate, lead titanate,
barium titanate, and/or lead metaniobate. In various embodiments,
in addition to, or instead of, a piezoelectrically active material,
transducers can comprise any other materials configured for
generating radiation and/or acoustical energy. In one embodiment,
when cylindrical transduction element 281 comprises a piezoelectric
ceramic material that is excited by an electrical stimulus, the
material may expand or contract. The amount of expansion or
contraction is related to boundary conditions in the ceramic as
well as the magnitude of the electric field created in the ceramic.
In some embodiments of conventional HIFU design, the front surface
(e.g. subject side) is coupled to water and the back surface of a
transducer 280 is coupled to a low impedance medium which is
typically air. In some embodiments, although the ceramic is free to
expand at the back interface, essentially no mechanical energy is
coupled from the ceramic to the air because of the significant
acoustic impedance disparity. This results in this energy at the
back of the ceramic reflecting and exiting the front (or subject
side) surface. As illustrated in an embodiment in FIGS. 3-5B, the
focus is created by forming, casting, and/or machining the ceramic
to the correct radius-of-curvature. In one embodiment, a flat
transducer material is bent to form a cylindrical transducer. In
various embodiments, transducers 280 and/or therapy elements 281
can be configured to operate at different frequencies and treatment
depths. Transducer properties can be defined by a focal length
(F.sub.L), sometimes referred to as a focal depth 278. The focal
depth 278 is the distance from the concave cylindrical surface to
the focal zone TTZ 550. In various embodiments, the focal depth 278
is the sum of a standoff distance 270 and a treatment depth 279
when the housing of a probe is placed against a skin surface. In
one embodiment, the standoff distance 270, or offset distance 270,
is the distance between the transducer 280 and a surface of an
acoustically transparent member 230 on the housing of a probe. The
treatment depth 279 is a tissue depth 279 below a skin surface 501,
to a target tissue. In one embodiment, the height of the aperture
in the curved dimension is increased or maximized to have a direct
effect on overall focal gain, which correlates to the ability to
heat tissue. For example, in one embodiment, the height of the
aperture in the curved dimension is maximized for a treatment depth
of 6 mm or less. In one embodiment, as the aperture is increased
(e.g. decreasing the f#), the actual heating zone gets closer to
the surface.
[0107] In one embodiment, a transducer can be configured to have a
focal depth 278 of 6 mm, 2-12 mm, 3-10 mm, 4-8 mm, 5-7 mm In other
embodiments, other suitable values of focal depth 278 can be used,
such as focal depth 278 of less than about 15 mm, greater than
about 15 mm, 5-25 mm, 10-20 mm, etc. Transducer modules can be
configured to apply ultrasonic energy at different target tissue
depths. In one embodiment, a therapy of 20 mm or less (e.g., 0.1
mm-20 mm, 5-17 mm, 10-15 mm). In one embodiment, a devices that
goes to 6 mm or less has a radius of curvature (ROC) of 13.6 mm,
with a ratio of treatment depth to ROC at approximately 44%. In one
embodiment, the height of the element is 22 mm In one embodiment,
using an aspect ratio for a treatment depth of 20 mm, the aperture
height would be 74.5 mm with a ROC of 45 mm
[0108] As illustrated in FIGS. 5A-5B, 7, 9 and 10 in several
embodiments, a system may comprise a movement mechanism 285
configured to move a transducer 280 comprising a cylindrical
transduction element 281 in one, two, three or more directions. In
one embodiment, a motion mechanism 285 can move in a linear
direction, one or both ways, denoted by the arrow marked 290 in
order move a TTZ 550 through tissue. In various embodiments, the
motion mechanism 285 can move the transducer in one, two, and/or
three linear dimensions and/or one, two, and/or three rotational
dimensions. In one embodiment, a motion mechanism 285 can move in
up to six degrees of freedom. Movement of the TTZ 550 can be with
the transducer continuously delivering energy to create a treatment
area 552. In one embodiment, a movement mechanism 285 can
automatically move the cylindrical transduction element 281 across
the surface of a treatment area so that the TTZ 550 can form a
treatment area 552.
[0109] As indicated in FIGS. 6, 7, and 8, a cylindrical
transduction element 281 can be connected to a motion mechanism 285
and placed inside a module 200 or a probe. In various embodiments,
a movement mechanism 285, or a motion mechanism 285, moves the
transducer 280 and/or treatment element 281 such that the
corresponding TTZ 550 moves to treat a larger treatment area 552.
In various embodiments, a movement mechanism 285 is configured to
move a transducer within a module or a probe. In one embodiment, a
transducer is held by a transducer holder. In one embodiment, the
transducer holder includes a sleeve which is moved along motion
constraining bearings, such as linear bearings, namely, a bar (or
shaft) to ensure a repeatable linear movement of the transducer. In
one embodiment, sleeve is a spline bushing which prevents rotation
about a spline shaft, but any guide to maintain the path of motion
is appropriate. In one embodiment, the transducer holder is driven
by a motion mechanism 285, which may be located in a hand wand or
in a module, or in a probe. In one embodiment, a motion mechanism
285 includes any one or more of a scotch yoke, a movement member,
and a magnetic coupling. In one embodiment, the magnetic coupling
helps move the transducer. One benefit of a motion mechanism 285 is
that it provides for a more efficient, accurate and precise use of
an ultrasound transducer, for imaging and/or therapy purposes. One
advantage this type of motion mechanism has over conventional fixed
arrays of multiple transducers fixed in space in a housing is that
the fixed arrays are a fixed distance apart. By placing transducer
on a track (e.g., such as a linear track) under controller control,
embodiments of the system and device provide for adaptability and
flexibility in addition to efficiency, accuracy and precision. Real
time and near real time adjustments can be made to imaging and
treatment positioning along the controlled motion by the motion
mechanism 285. In addition to the ability to select nearly any
resolution based on the incremental adjustments made possible by
the motion mechanism 285, adjustments can be made if imaging
detects abnormalities or conditions meriting a change in treatment
spacing and targeting. In one embodiment, one or more sensors may
be included in the module. In one embodiment, one or more sensors
may be included in the module to ensure that a mechanical coupling
between the movement member and the transducer holder is indeed
coupled. In one embodiment, an encoder may be positioned on top of
the transducer holder and a sensor may be located in a portion of
the module, or vice versa (swapped). In various embodiments the
sensor is a magnetic sensor, such as a giant magnetoresistive
effect (GMR) or Hall Effect sensor, and the encoder a magnet,
collection of magnets, or multi-pole magnetic strip. The sensor may
be positioned as a transducer module home position. In one
embodiment, the sensor is a contact pressure sensor. In one
embodiment, the sensor is a contact pressure sensor on a surface of
the device to sense the position of the device or the transducer on
the patient. In various embodiments, the sensor can be used to map
the position of the device or a component in the device in one,
two, or three dimensions. In one embodiment the sensor is
configured to sense the position, angle, tilt, orientation,
placement, elevation, or other relationship between the device (or
a component therein) and the patient. In one embodiment, the sensor
comprises an optical sensor. In one embodiment, the sensor
comprises a roller ball sensor. In one embodiment, the sensor is
configured to map a position in one, two and/or three dimensions to
compute a distance between areas or lines of treatment on the skin
or tissue on a patient.
[0110] In various embodiments, a motion mechanism 285 can be any
mechanism that may be found to be useful for movement of the
transducer. In one embodiment, the motion mechanism 285 comprises a
stepper motor. In one embodiment, the motion mechanism 285
comprises a worm gear. In various embodiments, the motion mechanism
285 is located in a module 200. In various embodiments, the motion
mechanism 285 is located in the hand wand 100. In various
embodiments, the motion mechanism 285 can provide for linear,
rotational, multi-dimensional motion or actuation, and the motion
can include any collection of points, lines and/or orientations in
space. Various embodiments for motion can be used in accordance
with several embodiments, including but not limited to rectilinear,
circular, elliptical, arc-like, spiral, a collection of one or more
points in space, or any other 1-D, 2-D, or 3-D positional and
attitudinal motional embodiments. The speed of the motion mechanism
285 may be fixed or may be adjustably controlled by a user. One
embodiment, a speed of the motion mechanism 285 for an image
sequence may be different than that for a treatment sequence. In
one embodiment, the speed of the motion mechanism 285 is
controllable by a controller.
[0111] In some embodiments, the energy transmitted from the
transducer is turned on and off, forming a non-continuous treatment
area 552 such that the TTZ 550 moves with a treatment spacing
between individual TTZ 550 positions. For example, treatment
spacing can be about 1 mm, 1.5 mm, 2 mm, 5 mm, 10 mm, etc. In
several embodiments, a probe can further comprise a movement
mechanism configured to direct ultrasonic treatment in a sequence
so that TTZs 550 are formed in linear or substantially linear
sequences. For example, a transducer module can be configured to
form TTZs 550 along a first linear sequence and a second linear
sequence separated by treatment spacing between about 2 mm and 3 mm
from the first linear sequence. In one embodiment, a user can
manually move the transducer modules across the surface of a
treatment area so that adjacent linear sequences of TTZs are
created.
[0112] In one embodiment, a TTZ can be swept from a first position
to a second position. In one embodiment, a TTZ can be swept from
the first position to the second position repeatedly. In one
embodiment, a TTZ can be swept from the first position, to the
second position, and back to the first position. In one embodiment,
a TTZ can be swept from the first position, to the second position,
and back to the first position, and repeated. In one embodiment,
multiple sequences of TTZs can be created in a treatment region.
For example, TTZs can be formed along a first linear sequence and a
second linear sequence separated by a treatment distance from the
first linear sequence.
[0113] In one embodiment, TTZs can be created in a linear or
substantially linear zone or sequence, with each individual TTZ
separated from neighboring TTZs by a treatment spacing, such as
shown in FIG. 9. FIG. 9 illustrates an embodiment of an ultrasound
system 20 with a transducer 280 configured to treat tissue at a
focal depth 278. In one embodiment, the focal depth 278 is a
distance between the transducer 280 and the target tissue for
treatment. In one embodiment, a focal depth 278 is fixed for a
given transducer 280. In one embodiment, a focal depth 278 is
variable for a given transducer 280. As illustrated in FIG. 9, in
various embodiments, delivery of emitted energy 50 at a suitable
focal depth 278, distribution, timing, and energy level is provided
by the module 200 through controlled operation by the control
system 300 to achieve the desired therapeutic effect of controlled
thermal injury to treat at least one of the epidermis layer 502,
dermis layer 503, fat layer 505, the SMAS layer 507, the muscle
layer 509, and/or the hypodermis 504. FIG. 9 illustrates one
embodiment of a depth that corresponds to a depth for treating
muscle. In various embodiments, the depth can correspond to any
tissue, tissue layer, skin, epidermis, dermis, hypodermis, fat,
SMAS, muscle, blood vessel, nerve, or other tissue. During
operation, the module 200 and/or the transducer 280 can also be
mechanically and/or electronically scanned along the surface 501 to
treat an extended area. Before, during, and after the delivery of
ultrasound energy 50 to at least one of the epidermis layer 502,
dermis layer 503, hypodermis 504, fat layer 505, the SMAS layer 507
and/or the muscle layer 509, monitoring of the treatment area and
surrounding structures can be provided to plan and assess the
results and/or provide feedback to the controller 300 and the user
via a graphical interface 310. In one embodiment, an ultrasound
system 20 generates ultrasound energy which is directed to and
focused below the surface 501. This controlled and focused
ultrasound energy 50 creates the thermal treatment zone (TTZ) 550.
In one embodiment, the TTZ 550 is a line. In one embodiment, the
TTZ 550 is a point. In one embodiment, the TTZ 550 is a two
dimensional region or plane. In one embodiment, the TTZ 550 is a
volume. In one embodiment, the ultrasound energy 50 heat treats the
subcutaneous tissue 510. In various embodiments, the emitted energy
50 targets the tissue below the surface 501 which heats, cuts,
ablates, coagulates, micro-ablates, manipulates, and/or causes a
lesion in the tissue portion 10 below the surface 501 at a
specified focal depth 278. In one embodiment, during the treatment
sequence, the transducer 280 moves in a direction denoted by the
arrow marked 290 to move the TTZ 550.
[0114] In various embodiments, an active TTZ can be moved
(continuously, or non-continuously) through tissue to form a
treatment area 552, such as shown in FIG. 10. With reference to the
illustration in FIG. 10, the module 200 can include a transducer
280 which can emit energy through an acoustically transparent
member 230. In various embodiments, a depth may refer to the focal
depth 278. In one embodiment, the transducer 280 can have an offset
distance 270, which is the distance between the transducer 280 and
a surface of the acoustically transparent member 230. In one
embodiment, the focal depth 278 of a transducer 280 is a fixed
distance from the transducer. In one embodiment, a transducer 280
may have a fixed offset distance 270 from the transducer to the
acoustically transparent member 230. In one embodiment, an
acoustically transparent member 230 is configured at a position on
the module 200 or the ultrasound system 20 for contacting the skin
surface 501.
[0115] In various embodiments, the focal depth 278 exceeds the
offset distance 270 by an amount to correspond to treatment at a
target area located at a tissue depth 279 below a skin surface 501.
In various embodiments, when the ultrasound system 20 placed in
physical contact with the skin surface 501, the tissue depth 279 is
a distance between the acoustically transparent member 230 and the
target area, measured as the distance from the portion of the hand
wand 100 or module 200 surface that contacts skin (with or without
an acoustic coupling gel, medium, etc.) and the depth in tissue
from that skin surface contact point to the target area. In one
embodiment, the focal depth 278 can correspond to the sum of an
offset distance 270 (as measured to the surface of the acoustically
transparent member 230 in contact with a coupling medium and/or
skin 501) in addition to a tissue depth 279 under the skin surface
501 to the target region. In various embodiments, the acoustically
transparent member 230 is not used.
[0116] In various embodiments, therapeutic treatment advantageously
can be delivered at a faster rate and with improved accuracy by
using a transducer configured to deliver energy to an expanded TTZ.
This in turn can reduce treatment time and decrease pain
experienced by a subject. In several embodiments, treatment time is
reduced by creating a TTZ and sweeping the TTZ through an area or
volume for treatment from a single transducer. In some embodiments,
it is desirable to reduce treatment time and corresponding risk of
pain and/or discomfort experienced by a patient. Therapy time can
be reduced by treating larger areas in a given time by forming
larger a TTZ 550, multiple TTZs simultaneously, nearly
simultaneously, or sequentially, and/or moving the TTZ 550 to form
larger treatment areas 552. In one embodiment, a reduction in
treatment time is reduced by treating a given area or volume with
multiple TTZs reduces the overall amount of movement for a device.
In some embodiments, overall treatment time can be reduced 10%,
20%, 25%, 30%, 35%, 40%, 4%, 50%, 55%, 60%, 65%, 70%, 75%, 80% or
more by through creation of continuous treatment areas 552 or
discrete, segmented treatment areas 552 from a sequence of
individual TTZs. In various embodiments, therapy time can be
reduced by 10-25%, 30-50%, 40-80%, 50-90%, or approximately 40%,
50%, 60%, 70%, and/or 80%. Although treatment of a subject at
different locations in one session may be advantageous in some
embodiments, sequential treatment over time may be beneficial in
other embodiments. For example, a subject may be treated under the
same surface region at one depth in time one, a second depth in
time two, etc. In various embodiments, the time can be on the order
of nanoseconds, microseconds, milliseconds, seconds, minutes,
hours, days, weeks, months, or other time periods. For example, in
some embodiments, the transducer module is configured to deliver
energy with an on-time of 10 ms-100 minutes (e.g., 100 ms, 1
second, 1-60 seconds, 1 minute-10 minutes, 1 minute-60 minutes, and
any range therein). The new collagen produced by the first
treatment may be more sensitive to subsequent treatments, which may
be desired for some indications. Alternatively, multiple depth
treatment under the same surface region in a single session may be
advantageous because treatment at one depth may synergistically
enhance or supplement treatment at another depth (due to, for
example, enhanced blood flow, stimulation of growth factors,
hormonal stimulation, etc.). In several embodiments, different
transducer modules provide treatment at different depths. In one
embodiment, a single transducer module can be adjusted or
controlled for varied depths.
[0117] In one embodiment, an aesthetic treatment system includes an
ultrasonic probe with a removable module that includes an
ultrasound transducer configured to apply ultrasonic therapy to
tissue at in a focal zone. In one embodiment, the focal zone is a
point. In one embodiment, the focal zone is a line. In one
embodiment, the focal zone is a two dimensional region or plane. In
one embodiment, the focal zone is a volume. In various embodiments,
a focal zone can be moved to sweep a volume between a first
position and a second position. In various embodiments, one or more
a focal zone locations are positioned in a substantially linear
sequence within a cosmetic treatment zone. In one embodiment, a
first set of locations is positioned within a first cosmetic
treatment zone and a second set of locations is positioned within a
second cosmetic treatment zone, the first zone being different from
the second zone. In one embodiment, the first cosmetic treatment
zone includes a substantially linear sequence of the first set of
locations and the second cosmetic treatment zone includes a
substantially linear sequence of the second set of locations.
[0118] In one embodiment, the transducer module 280 can provide an
acoustic power in a range of about 1 W or less, between about 1 W
to about 100 W, and more than about 100 W. In one embodiment, the
transducer module 280 can provide an acoustic power at a frequency
of about 1 MHz or less, between about 1 MHz to about 10 MHz, and
more than about 10 MHz. In one embodiment, the module 200 has a
focal depth 278 for a treatment at a tissue depth 279 of about 4.5
mm below the skin surface 501. Some non-limiting embodiments of
transducers 280 or modules 200 can be configured for delivering
ultrasonic energy at a tissue depth of 3 mm, 4.5 mm, 6 mm, less
than 3 mm, between 3 mm and 4.5 mm, between 4.5 mm and 6 mm, more
than more than 4.5 mm, more than 6 mm, etc., and anywhere in the
ranges of 0.1-3 mm, 0.1-4.5 mm, 0.1-6 mm, 0.1-25 mm, 0.1-100 mm,
etc. and any depths therein. In one embodiment, the ultrasound
system 20 is provided with two or more removable transducer modules
280. In one embodiment, a transducer 280 can apply treatment at a
tissue depth (e.g., about 6 mm). For example, a first transducer
module can apply treatment at a first tissue depth (e.g., about 4.5
mm) and a second transducer module can apply treatment at a second
tissue depth (e.g., of about 3 mm), and a third transducer module
can apply treatment at a third tissue depth (e.g., of about 1.5-2
mm). In one embodiment, at least some or all transducer modules can
be configured to apply treatment at substantially same depths. In
various embodiments, the tissue depth can be 1.5 mm, 2 mm, 3 mm,
4.5 mm, 7 mm, 10 mm, 12 mm, 14 mm, 15 mm, 17 mm, 18 mm, and/or 20
mm, or any range therein (including but not limited to 12-20 mm, or
higher).
[0119] In one embodiment, a transducer module permits a treatment
sequence at a fixed depth at or below the skin surface. In one
embodiment, a transducer module permits a treatment sequence at a
range of depths below the skin surface. In several embodiments, the
transducer module comprises a movement mechanism configured to move
the ultrasonic treatment at the TTZ. In one embodiment, the linear
sequence of individual TTZs has a treatment spacing in a range from
about 0.01 mm to about 25 mm For example, the spacing can be 1.1 mm
or less, 1.5 mm or more, between about 1.1 mm and about 1.5 mm,
etc. In one embodiment, the individual TTZs are discrete. In one
embodiment, the individual TTZs are overlapping. In one embodiment,
the movement mechanism is configured to be programmed to provide
variable spacing between the individual TTZs. In several
embodiments, a transducer module comprises a movement mechanism
configured to direct ultrasonic treatment in a sequence so that
TTZs are formed in linear or substantially linear sequences
separated by a treatment distance. For example, a transducer module
can be configured to form TTZs along a first linear sequence and a
second linear sequence separated by a treatment distance from the
first linear sequence. In one embodiment, treatment distance
between adjacent linear sequences of individual TTZs is in a range
from about 0.01 mm to about 25 mm. For example, the treatment
distance can be 2 mm or less, 3 mm or more, between about 2 mm and
about 3 mm, etc. In several embodiments, a transducer module can
comprise one or more movement mechanisms configured to direct
ultrasonic treatment in a sequence so that TTZs are formed in
linear or substantially linear sequences of individual thermal
lesions separated by a treatment distance from other linear
sequences. In one embodiment, the treatment distance separating
linear or substantially linear TTZs sequences is the same or
substantially the same. In one embodiment, the treatment distance
separating linear or substantially linear TTZs sequences is
different or substantially different for various adjacent pairs of
linear TTZs sequences.
Band Therapy Using A Cylindrical Transducer with An Imaging
Element
[0120] In various embodiments, including an imaging transducer or
imaging element with a cylindrical transduction element 281 can be
used to improve safety and/or efficacy of a treatment. In one
embodiment, an imaging element can be used to confirm acceptable
coupling between the ultrasound therapy transducer and/or identify
target tissue below the skin surface. As illustrated at FIGS. 21
and 22, in various embodiments, a transducer 280 comprises a
cylindrical transduction element 281 and one or more imaging
elements 284. The imaging element 284 is configured to image a
region of interest at any suitable tissue depths 279. In one
embodiment, an imaging element is centered on a therapy element. In
one embodiment, an imaging element is axis symmetric with a therapy
element. In one embodiment, an imaging element is not axis
symmetric with a therapy element. In one embodiment, the imaging
axis may be pointed in a completely different direction and
translated from the therapy beam axis. In one embodiment, the
number of imaging elements in the aperture may be greater than one.
For example, in one embodiment, the imaging elements may be located
on each corner of a cylinder pointed straight ahead and/or in the
middle. In one embodiment, a combined imaging and cylindrical
therapy transducer 280 comprises a cylindrical transduction element
281 and one or more imaging elements 284. In one embodiment, a
combined imaging and cylindrical therapy transducer 280 comprises a
cylindrical transduction element 281 with an opening 285 through
which one imaging element 284 is configured to operate. In one
embodiment, the opening 284 is a circular hole through the wall
thickness of the cylindrical transduction element 281 at the center
of the X-axis (azimuth) and Y-axis (elevation) of the cylindrical
transduction element 281. In one embodiment, the imaging element
284 is circular in cross-section and fits in the opening 284.
[0121] In one embodiment, first and second removable transducer
modules are provided. In one embodiment, each of the first and
second transducer modules are configured for both ultrasonic
imaging and ultrasonic treatment. In one embodiment, a transducer
module is configured for treatment only. In one embodiment, an
imaging transducer may be attached to a handle of a probe or a hand
wand. The first and second transducer modules are configured for
interchangeable coupling to a hand wand. The first transducer
module is configured to apply ultrasonic therapy to a first
treatment area, while the second transducer module is configured to
apply ultrasonic therapy to a second treatment area. The second
treatment area can be at a different depth, width, height,
position, and/or orientation than the first treatment area.
Band Therapy Using A Coated Transducer Configured to Reduce Edge
Effects
[0122] In various embodiments, treatment advantageously can be
delivered with improved accuracy. Further, efficiency, comfort and
safety can be increased if variance is reduced in a treatment area.
This in turn can reduce treatment time and decrease pain
experienced by a subject. In some instances, non-uniform heating at
a focal zone can result from geometric aspects of a transducer.
Inconsistencies in pressure or temperature profiles can be
attributed to edge effects, which can cause spikes in pressure or
temperature around the focal zone of a transducer. Thus, with edge
effects, instead of achieving a uniform line segment of heating,
the segment is broken into many isolated hot spots which may fail
to meet an objective a more uniform heat distribution at the focal
zone. This phenomenon is further exacerbated at high heating rates
which relate to elevated acoustic pressures. This is due to the
generation of nonlinear harmonics created especially in areas of
high pressure. Energy at harmonic frequencies is more readily
absorbed than energy at the fundamental frequency. In one
embodiment, energy absorption is governed by the following
equation:
H=2*.alpha.*f*p.sup.2/Z (1)
[0123] where alpha is the absorption constant in nepers per MHz cm,
f is frequency in MHz, p is the pressure at that frequency, Z is
the acoustic impedance of tissue, and H is the heating rate in
Watt/cm.sup.3. In one embodiment, the amount of harmonics produced
is proportional to the intensity. FIG. 23 shows the normalized
harmonic pressure at the focal depth across an azimuth of one
embodiment of a cylindrical element with an imaging element. FIG.
23 shows the rapid swings in harmonic pressure at this depth which
causes hot spots and non-uniform heating.
[0124] In one embodiment, a way to combat these hot and cold spots
that are the result from edge effects is to reduce the average
intensity at the focal depth and/or increase the heating time.
These two processes can reduce the amount on nonlinear heating as
well as allow for the conduction of the heat away from the hot spot
into the cold areas. The thermal conduction of tissue effectively
acts as a low pass filter to the acoustic intensity distribution as
the heating time increases. Although these methods may reduce the
non-uniform heating issues, they can also reduce the localization
of the heating zone and can also increase the treatment time.
Therefore, three performance areas of ultrasound therapy, e.g.
efficacy, comfort, and treatment time, are adversely affected. In
one embodiment, a more normalized pressure profile results in more
consistent therapy, such that temperature increase through heating,
coagulation, and/or ablation is more predictable and can better
ensure the desired or targeted temperature profiles are obtained in
the TTZ 550. In various embodiments, apodization of edge effects is
accomplished with transducers coated in specific regions.
[0125] In one embodiment, use of coatings, or shadings, can help
circumvents these issues such that efficacy, comfort and treatment
time are optimized. FIG. 24 shows a harmonic pressure distribution
from an embodiment of a shaded aperture, or a coated element, that
has an imaging transducer. In one embodiment, the coated element is
a coated cylindrical element with an imaging element. The variation
in harmonic pressure across the treatment line varies by less the
1.5 dB with the highest intensity near the center and sharp edges
at -10 mm and +10 mm. In one embodiment, the coated element design
does not require the conduction of heat away from hot spots since
the tissue along the focused line has a uniform temperature
increase during the absorption. Therefore, the amount of intensity
at the focus can be increased to localize the heating zone and
reduce treatment time.
[0126] In one embodiment, the coated element is a shaded
therapeutic cylinder. In one embodiment, a coated element also has
benefits outside the intended heating zone. In one embodiment, the
boundary between the heated and unheated junction is vastly
improved when compared to an uncoated element. FIG. 25 shows a
comparison of harmonic pressure across an azimuth of an embodiment
of a cylindrical element 280 compared to an embodiment of a coated
cylindrical element 600 at this boundary. FIG. 25 shows that, in
one embodiment, the possible harmonic pressures are approximately
20 dB lower for the shaded aperture with a coated cylindrical
element 600, which helps confine the heating zone and maximize
comfort. In one embodiment, areas of plating or non-plating are
initially used to define regions where the piezoelectric material
will be poled or not poled. Regions where there is plating define
regions that will be poled or actually mechanically vibrating. In
one embodiment, a cylindrical element 280 can be uncoated. Further,
an uncoated region may be considered uncoated to the extent it does
not have an electrically conductive coating--the uncoated region
may have other types of surface coatings in certain embodiments. In
one embodiment, a cylindrical element is completely coated. For
example, in one embodiment, a first transducer 280 includes a first
coated region 287 that fully plates the concave surface 282 of the
cylindrical transduction element and a second coated region 287
that fully plates the convex surface 283 of the cylindrical
transduction element. A second coated transducer 600 includes a
first coated region 287 that fully plates the concave surface 282
of the cylindrical transduction element and at least a second
coated region 287 that partially plates the convex surface 283 of
the cylindrical transduction element. As shown in FIG. 27, the
fully coated first transducer 281 demonstrates the spikes in focal
gain due to edge effects.
[0127] Referring to FIGS. 11A-13B, in one embodiment, transducer
treatment profiles were plotted based on theoretical and
experimental performance with a cylindrical transduction element
281 that was coated on the entire concave surface 282 and the
entire convex surface 283 with a coating. In one embodiment, the
coating is a metal. In one embodiment, the coating is a conductive
metal. In one embodiment, the coating is an electrical conductor.
In various embodiments, the coating is plated with any one or more
of silver, gold, platinum, mercury, copper or other materials. In
one embodiment, a coating comprises fired silver. In one
embodiment, a surface is fully coated. In one embodiment, a surface
is fully non-coated. In one embodiment, a surface is partially
coated and partially non-coated. The normalized pressure is
proportional to a thermal heating measure at the specified depth.
The discontinuous spikes (pointed regions at the top of the plots)
plots indicate pressure and/or temperature peaks that occur as a
result of the geometric edge effects of the geometry of the
cylindrical transduction element 281. In various embodiments, the
spikes, or peaks, can be reduced with a coated transducer 600
comprising one or more coated regions 287. In one embodiment, the
coated region 287 only partially coats a transducer surface. In one
embodiment, the coated region 287 does not completely coat a
transducer surface.
[0128] As shown in FIG. 26, in various embodiments, a coated
transducer 600 comprises a cylindrical transduction element 281
with one or more coated regions 287. In various embodiments, the
coated region 287 coats part, a portion, and/or all of a surface of
the transducer 600. In various embodiments, the coated region 287
coats part or all of a surface of the cylindrical transduction
element 281. In various embodiments, a coated transducer 600
comprises one or more imaging elements 284. In some embodiments,
one, two, three or more imaging element(s) are placed in `unused
regions` of coatings/shading for the purpose of imaging.
[0129] The edge effects from the geometry of one embodiment of a
combined imaging and cylindrical therapy transducer comprising a
cylindrical transduction element 281 with an opening 285 through it
are more pronounced due to the additional edges of the opening 285.
FIG. 27 is a plot illustrating focal gain across the azimuth of two
embodiments of combined imaging and cylindrical therapy transducers
with different coatings. A first transducer 280 includes a first
coated region 287 that fully plates the concave surface 282 of the
cylindrical transduction element and a second coated region 287
that fully plates the convex surface 283 of the cylindrical
transduction element. Both the first and the second coated regions
287 of the first transducer 280 are plated with silver. A second
coated transducer 600 includes a first coated region 287 that fully
plates the concave surface 282 of the cylindrical transduction
element and at least a second coated region 287 that partially
plates the convex surface 283 of the cylindrical transduction
element. Both the first and the second coated regions 287 of the
second transducer 600 are plated with silver. As shown in FIG. 27,
the fully coated first transducer 281 demonstrates the spikes in
focal gain due to edge effects. The partially coated second
transducer 600 has a more consistent, normalized performance output
with the spikes substantially reduced and/or removed. In various
embodiments, a coated transducer 600 reduces the peaks such that
variance around the focal depth is reduced by 1-50%, 25-100%,
75-200%, and/or 10-20%, 20-40% and 60-80%. In various embodiments,
a coated transducer 600 reduces the peaks such that variance of the
intensity in a location around the focal depth is +/-0.01-5 mm, 5
mm or less, 4 mm or less, 3 mm or less, 2 mm or less, 1 mm or less,
0.5 mm or less, 0.25 mm or less, 0.1 mm or less, 0.05 mm or less,
or any range therein. In various embodiments, a coated transducer
600 reduces the peaks in focal gain such that variance in focal
gain is 0.01-0.1, 0.01-1.0, 0.01-5, 0.01-10, 1-10, 1-5, 10, 9, 8,
7, 6, 5, 4, 3, 2, 1 or less, or any range therein.
[0130] As described in Example 2 below, FIGS. 28, 29, and 30
illustrate the embodiment of the performance of the partially
coated second transducer 600 in FIG. 27 at different depths. In the
illustrated embodiment, the partially coated second transducer 600
has a focal depth of 15 mm. In various embodiments, the focal depth
can be at any depth. In various embodiments, the focal depth is at
7, 8, 9, 10, 12, 13, 13.6, 14, 15, 16, 17, 18, or any depth
therein.
[0131] In one embodiment, the coated region 287 is plating. In one
embodiment, the coated region 287 is a conductive material. In one
embodiment, the coated region 287 is a semi-conductive material. In
one embodiment, the coated region 287 is an insulator material. In
various embodiments, the coated region 287 is silver, copper, gold,
platinum, nickel, chrome, and/or any conductive material that will
adhere with the surface of a piezoelectric material, or any
combinations thereof. In one embodiment, the coated region 287 is
silver plating.
[0132] In various embodiments, a cylindrical transduction element
281 has an azimuth (x-axis) dimension in the range of 1-50 mm, 5-40
mm, 10-20 mm, 15-25 mm, and/or 15 mm, 16 mm, 17 mm, 18 mm, 19 mm,
20 mm, 21 mm, 22 mm, 23 mm, 24 mm, and 25 mm In various
embodiments, a cylindrical transduction element 281 has an
elevation (y-axis) dimension in the range of 1-50 mm, 5-40 mm,
10-20 mm, 15-25 mm, and/or 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, 20
mm, 21 mm, 22 mm, 23 mm, 24 mm, and 25 mm In various embodiments, a
cylindrical transduction element 281 has focal depth (z-axis)
dimension in the range of 1-50 mm, 5-40 mm, 10-20 mm, 15-25 mm,
12-17 mm, 13-15 mm, and/or 10 mm, 11 mm, 12 mm, 13 mm, 13.6 mm, 14
mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, 20 mm, 21 mm, 22 mm, 23 mm,
24 mm, and 25 mm. In some non-limiting embodiments transducers can
be configured for a treatment zone at a tissue depth below a skin
surface of 1.5 mm, 3 mm, 4.5 mm, 6 mm, less than 3 mm, between 1.5
mm and 3 mm, between 1.5 mm and 4.5 mm, more than more than 4.5 mm,
more than 6 mm, and anywhere in the ranges of 0.1 mm-3 mm, 0.1
mm-4.5 mm, 3 mm-7 mm, 3 mm-9mm, 0.1 mm-25 mm, 0.1 mm-100 mm, and
any depths therein.
[0133] In various embodiments, a coated transducer 600 comprising a
cylindrical transduction element 281 has one, two, three, four, or
more coated regions 287. In one embodiment, a coated region 287
covers an entire surface of the element. In one embodiment, a
coated region 287 covers a portion of a surface of the element. In
various embodiments, the coated region 287 includes a conductive
plating. In one embodiment, a coated region 287 includes a silver
plating to form an electrode. When an electrical signal is applied
to an electrode at a coated region 287, the coated region 287
expands and/or contracts the corresponding portion of the
cylindrical transduction element 281. In various embodiments, the
coated region 287 has a shape or border that is a complete or a
partial point, edge, line, curve, radius, circle, oval, ellipse,
parabola, star, triangle, square, rectangle, pentagon, polygon, a
combination of shapes, or other shape. In various embodiments, a
coated transducer 600 can also comprise an opening 285.
[0134] In one embodiment illustrated at FIG. 31, a partially coated
transducer 600 comprising a cylindrical transduction element 281
has one, two, three, four, or more coated regions 287 of one or
more shapes on a convex 283 surface. In one embodiment, a partially
coated transducer 600 comprising a cylindrical transduction element
281 has one, two, three, four, or more coated regions 287 of one or
more shapes on a concave 282 surface. In various embodiments, the
coated region 287 has a lateral edge 293, a side edge 290, and a
medial edge 291. The various edges can be straight, curved, and/or
have a radius, and the sizes can be modified to result in various
performance profiles.
[0135] In one embodiment illustrated at FIG. 32, a partially coated
transducer 600 comprising a cylindrical transduction element 281
has one, two, three, four, or more circular, round, curved and/or
elliptical coated regions 287. In various embodiments, the coated
region 287 has a lateral edge 293, a side edge 290, and a medial
edge 291. The various edges can be straight, curved, and/or have a
radius, and the sizes can be modified to result in various
performance profiles.
[0136] In one embodiment illustrated at FIG. 33, a partially coated
transducer 600 comprising a cylindrical transduction element 281
has one, two, three, four, or more triangular coated regions 287.
In various embodiments, the coated region 287 has a lateral edge
293, a side edge 290, and a medial edge 291. The various edges can
be straight, curved, and/or have a radius, and the sizes can be
modified to result in various performance profiles.
[0137] In one embodiment illustrated at FIG. 34, a partially coated
transducer 600 comprising a cylindrical transduction element 281
has one, two or more square, rectangular, and/or polygon coated
regions 287. In various embodiments, the coated region 287 has a
lateral edge 293, a side edge 290, and a medial edge 291. The
various edges and/or sizes can be modified to result in various
performance profiles.
[0138] In one embodiment illustrated at FIG. 35, a partially coated
transducer 600 comprising a cylindrical transduction element 281
has one, two or more combined and/or mixed shape coated regions
287. In one embodiment illustrated at FIG. 35, a partially coated
transducer 600 is a combined imaging and cylindrical therapy
transducer comprising a cylindrical transduction element 281 with
an opening 285 for an imaging element 284. In one embodiment, the
coated transducer 600 includes a concave surface 282 that is fully
plated with fired silver, and has a convex surface 283 with two
coated regions 287 that are plated with fired silver to form
electrodes. When an electrical signal is applied to an electrode at
a coated region 287, the coated region 287 expands and/or contracts
the corresponding portion of the cylindrical transduction element
281. In some embodiments, the shape may be applied before or after
the poling process, as vibration will occur where the electrode is
located. In various embodiments, an electrode could be defined
before or after poling. In various embodiments, a coating pattern
may be on the concave or convex surface. In one embodiment, the
coated region 287 has a lateral edge 293, a first and second side
edge 290, and a medial edge 291 with a central edge 297. The
various edges can be straight, curved, and/or have a radius.
Various dimensions 294, 295, 296, and the various edges can be
modified to result in various performance profiles. In one
embodiment, the medial edge 291 along the curved dimension
(elevation) is a portion of an ellipse. In one embodiment, the
medial edge 291 along the curved dimension (elevation) is a portion
of a parabola. In one embodiment, the first and second side edge
290 along the uncurved dimension (azimuth) is a portion of a
parabola. In one embodiment, the first and second side edge 290
along the uncurved dimension (azimuth) is a portion of an
ellipse.
[0139] In one embodiment illustrated at FIG. 36, a partially coated
transducer 600 comprising a cylindrical transduction element 281
has one, two, three, four, or more diamond, rhombus, and/or other
polygon coated regions 287. In various embodiments, the coated
region 287 has a lateral edge 293, a side edge 290, and a medial
edge 291. The various edges and/or sizes can be modified to result
in various performance profiles.
[0140] In one embodiment illustrated at FIGS. 37 and 38, a
partially coated transducer 600 comprising a cylindrical
transduction element 281 has one, two, three, four or more coated
regions 287. In various embodiments, the coated region 287 has a
lateral edge 293, a side edge 290, and a medial edge 291. In some
embodiments, the coated region 287 is configured to position one,
two, three, four, or more (e.g., multiple) thermal treatment zones
through poling, phasic poling, biphasic poling, and/or multi-phasic
poling. Various embodiments of ultrasound treatment and/or imaging
devices with of multiple treatment zones enabled through poling,
phasic poling, biphasic poling, and/or multi-phasic poling are
described in U.S. application Ser. No. 14/193,234 filed on Feb. 28,
2014, which is incorporated in its entirety by reference
herein.
Non-Therapeutic Uses of a Coated Cylindrical Transducer With
Reduced Edge Effects
[0141] In various embodiments, a coated cylindrical transducer 600
comprising one or more coated regions 287 is configured for
non-therapeutic use.
[0142] In one embodiment, a coated cylindrical transducer 600
comprising one or more coated regions 287 is configured for
materials processing. In one embodiment, a coated cylindrical
transducer 600 comprising one or more coated regions 287 is
configured for ultrasonic impact treatment for the enhancement of
properties of a material, such as a metal, compound, polymer,
adhesive, liquid, slurry, industrial material.
[0143] In one embodiment, a coated cylindrical transducer 600
comprising one or more coated regions 287 is configured for
material heating. In various embodiments, the cylindrical
transducer 600 is configured for cooking, heating, and/or warming
materials, food, adhesives or other products.
Heating Tissue and Quantification of Thermal Dose for Ultrasound
Band Therapy
[0144] As described above, in various embodiments, systems and/or
methods provide non-invasive dermatological treatment to tissue
through heating, hyperthermia, thermal dosimetry, thermal
treatment, coagulation, ablation, apoptosis, lysis, increasing
tissue volume, decreasing or reducing tissue volume, and/or tissue
tightening. In one embodiment, dermal tissue volume is increased.
In one embodiment, fat tissue volume is reduced, or decreased.
[0145] In various embodiments, band treatment involves metrics that
quantify the magnitude of adipocyte death with heat. For example,
in one embodiment, thermal dosage in a heat treatment relates
time-temperature curves back to a single reference temperature,
e.g. T=43 degrees Celsius, using the Arrhenius equation. In one
embodiment, a band treatment is configured under a relationship
that that for every 1 degree Celsius increase in tissue temperature
above in a range above body temperature, the rate of cell death
doubles. A theoretical survival fraction can then be determined by
comparing the thermal dose to empirical data from the
literature.
[0146] In various embodiments, band treatment provides improved
thermal heating and treatment of tissue compared to diathermy or
general bulk heating techniques. In general, normal body
temperatures tend to range between about 33-37 degrees Celsius. In
various embodiments, as tissue is heated in a range of about 37-43
degrees Celsius, physiological hyperthermia can take place, and
exposure to this temperature range on order of, for example, a few
hours, can result in increased normal tissue metabolism and/or
increased normal tissue blood flow, and in some embodiments,
accelerated normal tissue repair. As temperature in the tissues
reaches the higher .about.43 degrees Celsius range and/or the
tissue is subject to the temperature for longer periods of time
(e.g., 2 hours, 3, hours or more) the tissue can experience acute
tissue metabolism and/or acute tissue blood flow, and in some
embodiments, accelerated normal tissue repair. In one embodiment,
heating (e.g., bulk heating) of tissue to a range of about 42-55
degrees Celsius is performed. In various embodiments, heating of
tissue to about 43-50 degrees Celsius can be considered adjuvant
synergistic hyperthermia, and exposure to this temperature range on
order of, for example, a few minutes, can result in immediate or
delayed cell death, apoptosis, decreased tumor metabolism,
increased tissue oxygen levels, increased tissue damage, increased
sensitivity to therapy, vascular status, DNA damage, cell
reproductive failure, and/or cell destruction. In various
embodiments, heating of tissue to about 50-100 degrees Celsius can
be considered surgical hyperthermia, and exposure to this
temperature range on order of, for example, a few seconds or
fractions of a second, can result in coagulation, ablation,
vaporization, and immediate cell destruction.
[0147] In some embodiments of the invention, the temperature of the
tissue treatment site (e.g., the adipocytes) is elevated to 38-43
degrees Celsius, and according to one embodiment, thereby
increasing tissue metabolism and perfusion and accelerating tissue
repair mechanisms. In other embodiments, the temperature of the
tissue treatment site (e.g., the adipocytes) is elevated to 43-50
degrees Celsius, which in one embodiment can increase cell damage
starts and result in immediate cell death, particularly when the
temperature remains elevated on the order of several minutes to an
hour (or longer). In yet other embodiments, the temperature of the
tissue treatment site (e.g., the adipocytes) is elevated to above
50 degrees Celsius, which in one embodiment results in protein
coagulation on the order of seconds and less and can lead to
immediate cell death and ablation. In various embodiments, the
temperature of the tissue treatment site is heated to 40, 41, 42,
43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59,
60, 61, 62, 63, 64, 65, 70, 75, 80, 90, or 100 degrees Celsius,
and/or any range therein. In various embodiments, a treatment area
has uniform temperature, a variance of 1%, 2%, 3%, 4%, 5%, 6%, 7%,
8%, 9%, 10%, 12%, 15%, 20%, 25%, 30%, 40%, 50% or more. In various
embodiments, a treatment area has a variance of +/-0, 1, 2, 3, 4,
5, 6, 7, 8, 9, 10, 12, 15, 20, 25 degrees Celsius or more.
[0148] In several embodiments, the invention comprises elevating
the temperature of the tissue treatment site (e.g., the adipocytes)
is elevated to 38-50 degrees Celsius for a time period between
1-120 minutes, and then optionally increasing the temperature in
one, two, three, four five or more increments by 10-50%. As an
example using three increments, the target temperatures may be
increased as follows: (i) elevate temperature to about 40-42
degrees Celsius for 10-30 minutes, (ii) then optionally increase
temperature by about 20% to elevate temperature to about 48-51
degrees Celsius for 1-10 minutes, and (iii) then optionally
increase by about 10-50% for a shorter time frame. As another
example, the target temperature may be increased as follows: (i)
elevate temperature to about 50 degrees Celsius for 30 seconds to 5
minutes (e.g., about 1 minute) to destroy over 90%, 95% or 99% of
target (e.g., adipose) cells, with an optional pre-heating step of
raising the temperature to 38-49 degrees Celsius for a period of
10-120 minutes prior to the elevation to 50 degrees Celsius. As yet
another example, in some embodiments, a non-invasive, cosmetic
method of heating tissue, comprises applying a cosmetic heating
system to a skin surface, wherein the cosmetic heating system
comprises a hand-held probe, wherein the hand-held probe comprises
a housing that encloses an ultrasound transducer configured to heat
tissue below the skin surface to a tissue temperature in the range
of 40-50 degrees Celsius, wherein the ultrasound transducer
comprises a cylindrical transduction element comprising a first
surface, a second surface, a coated region, and an uncoated region,
wherein the coated region comprises an electrical conductor,
wherein the first surface comprises at least one coated region,
wherein the second surface comprises the uncoated region and a
plurality of coated regions, applying a current to the plurality of
coated regions, thereby directing ultrasound energy to a linear
focal zone at a focal depth, wherein the ultrasound energy produces
a reduction in focal gain at the linear focal zone, thereby heating
the tissue at the focal depth in the linear focal zone to the
tissue temperature in the range of 40-50 degrees Celsius for a
cosmetic treatment duration of less than 1 hour, thereby reducing a
volume of an adipose tissue in the tissue.
[0149] In one embodiment, a band therapy system uses a relationship
between cell death and time-temperature dosages as quantified using
the Arrhenius equation. The Arrhenius equation shows an exponential
relationship exists between cell death and exposure time and
temperature. Above a certain break temperature, the increase in the
rate of cell killing with temperature is relatively constant.
Time-temperature relationships to achieve isoeffective dose in
several types of tissue appears to be conserved both in vitro and
in-vivo across multiple cell types.
[0150] In some embodiments, clinical situations involve ramp-up of
temperatures, cooling, and fluctuations when approaching and
maintaining a steady state temperature. In various embodiments,
different thermal profiles can produce the same thermal dose. In
order to estimate the thermal dosage from a time-varying thermal
profile, a temperature curve is discretized into small time steps,
and the average temperature during each time step is calculated.
The thermal dosage is then calculated as an equivalent exposure
time at the break temperature (43 degrees Celsius) by integrating
these temperatures according to equation (2):
t 43 - t = 0 t = final R ( 43 - T ) .DELTA. t t 43 : Equivalent
time at 43 .degree. C . T ~ : Average temperature during .DELTA. t
R = { 0.5 , T .gtoreq. 43 .degree. C . 0.25 , T < 43 .degree. C
. } ( 2 ) ##EQU00001##
[0151] Equation (2) suggests that the increase in the rate of
killing with temperature is relatively constant. In some
embodiments, a 1 degree Celsius increase above a break point
results in the rate of cell death doubles. FIGS. 39 and 40
illustrate theoretical cell death fractions over time depending on
tissue temperature, with higher theoretical cell killing fractions
at higher temperatures and/or higher periods of time. The higher a
kill fraction (such as shown with kill fractions of 99%, 80%, 50%,
40%, and 20%) the higher a temperature and/or a time is used in an
embodiment of a treatment.
[0152] Once a thermal dose has been calculated, a dose survival
response can be estimated from empirical data. In one embodiment,
an isoeffective dose of 43 degrees Celsius for 100 minutes
theoretically yields a cell survival fraction of 1%. Based on the
Arrhenius relationship, a similar surviving fraction can be
obtained with an isoeffective dose of 44 degrees Celsius for 50
minutes, or 25 minutes at 45 degrees Celsius, etc. as tabulated in
the table listing isoeffective dosages to theoretically achieve 1%
survival fraction at FIG. 41, according to embodiments of the
present invention.
[0153] In various embodiment, simulations of various embodiments of
band therapy using a cylindrical transducer source conditions
linked to the relationship between tissue and heat equation showed
that successive treatment pulses obey linear superposition, which
allows for simplification of the heat transfer physics so that the
heating rate may be described as a temperature rise per time
(degrees Celsius/sec), and as a temperature rise per pass (degrees
Celsius/button push).
Heating Tissue via Ultrasound Band Therapy
[0154] In various embodiments, a band therapy system is configured
for treating the tissue. For example, in one embodiment, a band
treatment is configured for treatment of supraplatysmal submental
fat. In one embodiment, a treatment of fat includes selectively
causing thermal heat shock followed by apoptosis to a fat layer, at
a depth of about 2.5-6.0 mm, without causing any major skin surface
effects. In one embodiment, the treatment involves exposing fat to
a bulk heating treatment with a temperature of 42-55 degrees
Celsius for 1-5 minutes without exceeding 41 degrees Celsius on the
skin surface, with physiologic/biologic effect (e.g. one or more of
coagulation, apoptosis, fat cell lysis, etc.). In various
embodiments, treatment with a band transducer treats tissue with
isoeffective doses, as shown in a graph representing various levels
of theoretical cell kill fractions in FIG. 42.
[0155] In various embodiments, a theoretical review of the effect
of stacking multiple treatment pulses using the
Khokhlov-Zabolotskaya-Kuznetsov (KZK) Equation was implemented with
cylindrical source acoustic geometry, linked to a bioheat equation
(e.g., in one embodiment, using the Arrhenius equation). FIG. 43
shows the results of a KZK simulation of cylindrical transducer
output showing linear superposition of multiple pulses;
approximately the same temperatures are reached when treating with
3 pulses of 0.45 J or 1 pulse of 1.35 J (3*0.45 J). The results of
a theoretical experiment with one embodiment of a band therapy
system as shown in FIG. 43, suggest non-linear acoustics are not a
major contributor to the final temperature for the energies, and
suggests that body tissue acts as a linear time-invariant system,
which allows for simplification of the heat transfer physics, and
the heating and cooling rates to be described in relatively few
parameters. In various embodiments, a therapy system with a hand
wand 100 includes a module 200 with one or more ultrasound
transducers 280. In some embodiments, an ultrasound transducer 280
includes one or more cylindrical ultrasound elements 281, as shown
in FIGS. 5A-8. The cylindrical transducer element 281 is configured
for bulk heating treatments with its linear focus along an axis,
resulting in a continuous line that can be moved with an automated
motion mechanism to treat a rectangular plane. In one embodiment,
lines of treatment are deposited perpendicular to the direction of
motor movement in a single direction. A single "pass" of treatment
creates a number of therapy lines equal to {Length}/{Spacing}.
[0156] In various embodiments, various cylindrical geometries were
tested from the first build (4.5 MHz-12 mm width at 4.5 mm and 6.0
mm depths); however, acoustic tank testing showed higher acoustic
pressures (and therefore heating rates) at the each edge of the
therapy line. In one embodiment, a ceramic transducer was apodized
to produce a flat thermal profile, as shown in FIGS. 44 and 45. In
various embodiments, different cylindrical geometries based on two
operating frequencies, two treatment widths, and two treatment
depths were built: (1) 3.5 MHz -22 mm Width-4.5 mm Depth; (2) 3.5
MHz-22 mm Width-6.0 mm Depth; (3) 4.5 MHz-22 mm Width-4.5 mm Depth;
(4) 4.5 MHz-22 mm Width-6.0 mm Depth; (5) 3.5 MHz-12 mm Width-4.5
mm Depth; (6) 4.5 MHz-12mm Width-4.5 mm Depth; (7) 3.5 MHz-12 mm
Width-6.0 mm Depth; and (8) 4.5 MHz-12 mm Width-6.0 mm Depth. In
various embodiments, a tissue temperature measurement system
included one or more of including IR thermography, temperature
strips, and resistance temperature detectors (RTDs), and
thermocouples. IR thermography can be used to read skin surface
temperatures. Temperature strips are able to provide peak
temperature reached. RTD sheaths have a large thermal mass and may
have a slow response time. In various embodiments, thermocouples
have a response time less than a second, which is helpful for
measuring the heating and cooling phase of a single treatment pass.
Thermocouples also have the advantage of being small enough that
they can be positioned through a large bore needle to the desired
tissue depth. In one embodiment, a particular isoeffective dose is
attached via the heating phase followed by a maintenance phase in
which the system or an operator pulses treatment at an interval to
sustain a steady state temperature. A parameter of interest during
this phase is the average pulse period needed to maintain the
steady state temperature.
Body Contouring via Ultrasound Band Therapy
[0157] In various embodiments, a band therapy system is configured
for body contouring. In one embodiment, body contouring treatment
involves thermal heat shock concurrent with, and/or followed by
apoptosis. In one embodiment, body contouring treatment involves
exposing fat to 42-55 degrees Celsius for 1-5 minutes to induce
delayed apoptosis. In one embodiment, body contouring treatment
involves exposing fat at a focus depth of at least 13 mm below the
skin surface.
Temperature and Dose Control
[0158] In various embodiments, one or more sensors may be included
in the module 200 or system 20 to measure a temperature. In one
embodiment, methods of temperature and/or dose control are
provided. In one embodiment, temperature is measured to control
dosage of energy provided for a tissue treatment. In various
embodiments, a temperature sensor is used to measure a tissue
temperature to increase, decrease, and/or maintain the application
of energy to the tissue in order to reach a target temperature or
target temperature range. In some embodiments, a temperature sensor
is used for safety, for example, to reduce or cease energy
application if a threshold or maximum target temperature is
reached. In one embodiment, a cooling device or system can be
employed to cool a tissue temperature if a certain temperature is
reached. In some embodiments, a temperature sensor is used to
modulate an energy dose, for example, via modulation, termination
of amplitude, power, frequency, pulse, speed, or other factors.
[0159] In one embodiment, a temperature sensor is used to measure a
skin surface temperature. In one embodiment, a temperature sensor
may be positioned on top of the transducer holder and a sensor may
be located in a portion of the module, or vice versa (swapped). In
various embodiments, a temperature sensor is positioned on a system
or module housing, such as in one embodiment, near or on an
acoustic window, such as an acoustically transparent member 230. In
one embodiment, one or more temperature sensors are positioned
around or proximate an acoustically transparent member 230. In one
embodiment, one or more temperature sensors are positioned in or on
an acoustically transparent member 230. In one embodiment, a
temperature sensor measure from a skin surface can be used to
calculate a temperature in a tissue at the focus depth of the
energy application. In various embodiments, a target tissue
temperature can be calculated and/or correlated to the depth in
tissue, type of tissue (e.g. epidermis, dermis, fat, etc.) and
relative thickness of tissue between the skin surface and the focus
depth. In some embodiments, a temperature sensor provides a
temperature measurement for a signal to a control system. In some
embodiments, a temperature sensor provides a temperature
measurement for visual and/or auditory feedback to a system
operator, such as a text, color, flash, sound, beep, alert, alarm,
or other sensory indicator of a temperature state.
[0160] In some embodiments, imaging can be used to control energy
dose. In one embodiment, a thermal lens effect can be used to
account for speckle shift and/or feature shift to indicate a
temperature of a tissue at a target location, such as at a focus
depth in tissue below the skin surface. In one embodiment, Acoustic
Radiation Force Impulse (ARFI) imaging is used to calculate a
tissue temperature. In one embodiment, Shear Wave Elasticity
Imaging (SWEI) is used to calculate a tissue temperature. In one
embodiment, attenuation is used to calculate a tissue
temperature.
[0161] In various embodiments, a variable dose delivery technique
is used to attain a target temperature in a tissue and maintain
that target temperature. The body temperature at a depth in tissue
surrounds a thermal treatment zone (TTZ). In one embodiment, to
overcome the body temperature, a treatment focuses energy at the
TTZ at a first rate to bring the tissue temperature in the TTZ to a
target temperature. Once that target temperature is attained, the
second rate can be reduced or stopped to maintain the tissue at the
target temperature.
[0162] In some embodiments, energy is focused at a depth or
position in tissue at the TTZ, such that the temperature in the
focal zone is increased. However, at the edges (e.g., ends, top,
bottom, sides, etc.) of the focal zone, a boundary condition at
body temperature can result in temperature fluctuations at the
boundaries of the treatment area 552. In various embodiments,
movement of the TTZ 550 can be with the transducer delivering
energy to create a treatment area 552. In one embodiment, a
movement mechanism 285 can automatically move the cylindrical
transduction element 281 across the surface of a treatment area so
that the TTZ 550 can form a treatment area 552. In FIG. 53, the
treatment area 552 is surrounded at the edges by body temperature,
or approximately body temperature. In some embodiments, the
temperature in the treatment area 552 along the edges/boundary are
lower than the desired, target temperature.
[0163] In various embodiments, mechanical velocity modulation is
used to attain a specific thermal distribution in the treatment
area 552. In one embodiment, in order to attain a more uniform
temperature in the treatment area 552, the applied temperature at
the edges/boundaries is increased to counteract the surrounding
body temperature difference. FIG. 54 illustrates an embodiment of
mechanical velocity modulation in which the velocity, or speed of
the automatic motion of the motion mechanism moving the transducer
along direction 290 (along the elevation direction), is varied to
provide a more uniform temperature in the treatment area 552 by
slowing near the boundaries, resulting in increased temperature at
the boundaries (start and stop position, such as along a 25 mm
travel distance, in one embodiment). The increased velocity near
the middle delivers a lower temperature than the decreased
velocity.
[0164] In various embodiments, amplitude modulation is used to
attain a specific thermal distribution in the treatment area 552.
In one embodiment, in order to attain a more uniform temperature in
the treatment area 552, the applied temperature at the
edges/boundaries is increased to counteract the surrounding body
temperature difference. FIG. 55 illustrates an embodiment of
amplitude modulation in which the amplitude (correlates to power)
of the energy delivered by the transducer as the automatic motion
of the motion mechanism moves along direction 290 (along the
elevation direction), is varied to provide a more uniform
temperature in the treatment area 552 by increasing amplitude near
the boundaries, resulting in increased temperature at the
boundaries (start and stop position, such as along a 25 mm travel
distance, in one embodiment). The lower amplitude near the middle
delivers a lower temperature than the higher amplitude near the
boundaries.
[0165] In various embodiments, aperture apodization is used to
attain a specific thermal distribution in the treatment area 552.
In one embodiment, aperture apodization along the non-focused
dimension (such as along TTZ 550 and/or the azimuth direction) is
used in order to attain a more uniform temperature in the treatment
area 552. The applied temperature at the end points, along the
edges/boundaries is increased to counteract the surrounding body
temperature difference. FIG. 56 illustrates an embodiment of
aperture apodization in which the amplitude of the energy delivered
by the transducer along the TTZ 550 is varied to provide a more
uniform temperature in the treatment area 552 by increasing
amplitude near the end points near the boundaries, resulting in
increased temperature at the boundaries (with L as a length of the
focused line TTZ 550, L/2 from center is the end point). The lower
amplitude near the middle delivers a lower temperature than the
higher amplitude near the boundaries. In various embodiments, a
temperature profile can be generated along the TTZ with embodiments
of a coated transduction element 600, such as illustrated in FIGS.
31-38.
[0166] In various embodiments, pulsing and/or duty cycles are
controlled to attain a specific thermal distribution in the
treatment area 552. At FIG. 57, in various embodiments, treatment
patterns can have a consistent or a constant pulsing or duty cycle.
At FIG. 58, in various embodiment, treatment patterns can have
variable pulsing or a variable duty cycle, with variations in any
of peak amplitude, spacing of application, duration of application.
As shown in FIG. 58, the application of energy is longer and covers
more area near the boundary of the treatment area 552, while the
internal region has less power application for a corresponding
lower temperature application in the internal region.
[0167] In various embodiments, treatment patterns are used to
attain a specific thermal distribution in the treatment area 552.
In some embodiments the TTZ 550 has a dimension (e.g., width,
height, thickness, etc.). In some embodiments, the pulsed
application of TTZ 550 is non-overlapping, as shown in FIG. 59. In
some embodiments, the pulsed application of TTZ 550 is overlapping,
as is shown near a boundary in FIG. 60, where the amount of
overlapping can be constant or vary. As shown in the embodiment in
FIG. 60, the amount of overlap varies and includes a
non-overlapping portion. In various embodiments, a cross hatching
pattern is used, wherein the system hand piece is rotated about 90
degrees, or orthogonally, and the motion mechanism is operated in
one or more additional passes over a target tissue region in an
orthogonal direction to a prior treatment pass.
[0168] In various embodiments, a specific thermal distribution in
the treatment area 552 comprises treatment with a tissue
temperature of 37-50 degrees Celsius for a duration of minutes to
hours to cause a targeted percentage of cell death (such as fat
cell death) which a relationship can be determined via Arrhenius
equation, such as is shown on the left side of FIG. 61. In various
embodiments, a specific thermal distribution in the treatment area
552 comprises treatment with a tissue temperature of over 60
degrees Celsius for a duration of seconds to fractions of a second
(or near instantaneous) coagulation, ablation, and/or cell death
(such as fat cell death) at the elevated temperature, such as shown
on the right side of FIG. 62. In various embodiments, a treatment
can be either one, or both in sequence and/or simultaneous
treatments.
[0169] In some embodiments, one, two, three, four, or more of
mechanical velocity modulation, amplitude modulation, aperture
apodization, pulsing duty cycles, and/or treatments at different
temperatures can be used to achieve a desired temperature profile
across the treatment area 552. In various embodiments, one or more
of mechanical velocity modulation, amplitude modulation, aperture
apodization, pulsing duty cycles, and/or treatments at different
temperatures is used to create a temperature profile, wherein the
temperature profile can include areas for increased, decreased,
and/or uniform temperatures. In some embodiments, one, two, or more
types of treatment are applied in one, two, or three dimensions
(along any of the azimuth, elevation, and/or depth directions) and
is configured for treatment in any of one, two, or three dimensions
to create a one, two, or three dimensional temperature profile.
[0170] In some embodiments, a compound lens system produces various
peak intensities and different depths. In various embodiments, a
mechanical and/or electronic focus lens can be used in any one or
more of the azimuth, elevation, and/or depth directions. As
illustrated in FIG. 62 and FIG. 63, a compound lens system can
create two or more focal lines 550 and 550a.
[0171] In various embodiments, an ultrasound system 20 comprises a
motion mechanism 285 configured for moving a plurality of
ultrasound transducers 280 and/or a plurality of ultrasound
elements 281. In some embodiments, such as illustrated in an
embodiment at FIG. 64, the motion mechanism 285 is configured to
minimize heat fluctuation in treated tissue and reduce treatment
time by presenting the plurality of elements 281 on a conveyor
system, such as with a belt and/or pulley system that can move the
plurality of elements 281 at a velocity v. In various embodiments,
velocity can be constant, variable, zero (e.g., stopped),
reversible (e.g., forward and backward, left and right, first
direction and second direction, etc.) and/or have values in the
range 0-100 RPM, 1 RPM-50 RPM, or other velocities. In various
embodiments, the velocity is any value 1-1,000 cm/second (e.g., 10,
20, 50, 100, 200, 500, 1000 cm/sec, and any other values therein).
In various embodiments, the motion mechanism 285 moves one, two,
three, four, five, six, seven, eight, or more ultrasound elements
281. In various embodiments, ultrasound elements 281 are connected,
or spaced at a distance of 0.01-10 cm apart, (e.g., 0.1, 0.5, 1,2,
5 cm and any values therein), such that one, two, or more
ultrasound elements 281 are configured to treat a treatment
area.
[0172] In some embodiments, imaging is used to confirm the quality
of the acoustic coupling between a treatment device and the skin.
In one embodiment, clarity of an ultrasound image along a treatment
area, line, or point is used to determine the extent to which a
device is acoustically coupled to a skin surface. In one
embodiment, defocused imaging and/or Voltage Standing Wave Ratio
(VSWR) from backscatter is used to check acoustic coupling for a
treatment.
[0173] In some embodiments, a treatment is automated. In one
embodiment, a treatment is set up by acoustically coupling a system
to a skin surface, and the movement mechanism and treatment is
automated to function. In various embodiments, the system is
coupled to a skin surface via suction. In various embodiments, a
system operator couples the system to a skin surface, activates the
system, and can leave the system to automatically perform a
treatment, or a portion of a treatment. In one embodiment, a system
uses suction and/or vacuum pressure to hold a probe or portion of
the system to a skin surface, allowing the system user to initiate
treatment and leave the system to automatically perform a treatment
or a portion of a treatment for a period of time. In some
embodiments, a treatment system includes a TENS stimulation device
to reduce pain at a skin treatment site.
Theoretical and Experimental Treatments with A Cylindrical
Transducer
[0174] The following examples illustrate various non-limiting
embodiments.
EXAMPLE 1
[0175] The following example is intended to be a non-limiting
embodiment of the invention.
[0176] As illustrated at FIGS. 11A-20, it was experimentally
verified that an embodiment of a transducer 280 comprising a
cylindrical transduction element 281, which was applied to a
simulated target tissue, an artificial tissue, and to porcine
tissue sample, formed localized, linear thermal treatment zone (TTZ
550) in a targeted focal area 552. In the experiment, the single
cylindrical transduction element 281 was constructed with a radius
and focal depth of 15 mm. The size of the cylindrical transduction
element 281 was 20 mm (azimuth) by 17 mm (elevation). Additional
focal gain could be achieved with a larger aperture. Depth is
limited by frequency and focal gain, and was set to 6 mm below a
simulated tissue surface.
[0177] In FIGS. 11A-13B, treatment profiles were plotted based on
theoretical and experimental performance with a cylindrical
transduction element 281. The normalized pressure is proportional
to a thermal heating measure at the specified depth. The spikes
(pointed regions at the top of the plots) plots indicate pressure
peaks that occur as a result of the geometric edge effects of the
geometry of the cylindrical transduction element 281. The spikes
are visible in both the theoretical and the experimental
performance results. The software simulated experiments reflect the
theoretical performance of the 15 mm cylindrical transduction
element 281 in FIGS. 11A, 12A, 13A, 14A, 15A, and 16A. The physical
experiments in simulated tissue were performed and measured, with
results in FIGS. 11B, 12B, 13B, 14B, 15B and 16B.
[0178] In FIGS. 11A-11B and 14A-14B, the depth is 20 mm, where the
normalized pressure peaks at a value of roughly 0.15. As shown in
FIG. 14A-14B, the normalized pressure is not visible. In FIGS.
12A-12B and 15A-15B, the depth is the designed, optimal 15 mm,
where the normalized pressure peaks at a value of roughly 0.8. As
shown in FIG. 15A-15B, the normalized pressure is clearly visible,
with peak normalized pressures at approximately 0.9-1.0. The size
of the cylindrical transduction element 281 was 20 mm (azimuth) by
17 mm (elevation). The size of the TTZ 550 at a depth of 15 mm was
about 0.5 mm thick (along azimuth) by 17 mm width (along
elevation). In FIGS. 13A-13B and 16A-16B, the depth is 13 mm, where
the normalized pressure peaks at a value of roughly 0.25. As shown
in FIG. 16A-16B, the normalized pressure is barely visible. As
shown through both the theoretical and experimental data, the
normalized pressure corresponding to the TTZ 550 for a 15 mm focal
depth cylindrical transduction element 281 is at the 15 mm depth,
with a linear TTZ 550.
[0179] As illustrated at FIGS. 17-20, it was experimentally
verified that the embodiment of a transducer 280 comprising a
cylindrical transduction element 281, which was applied to a
porcine tissue sample (muscle tissue), formed localized, linear
thermal treatment zone (TTZ 550) in a targeted focal area 552. In
the experiment, an embodiment of a transducer 280 comprising a
cylindrical transduction element 281 was passed over the porcine
muscle tissue with three passes in 20 seconds, operating at 4.5 MHz
and a tissue depth of 6 mm. As shown in FIG. 17, the three passes
(shown with the three spikes in temperature) increased the
temperature of the porcine muscle. Two power levels are shown. The
40 W porcine muscle started at 30 degrees Celsius, and over the
course of 20 seconds (between the 20 and 40 second marks) of
heating through three passes of the cylindrical transduction
element 281 over the target tissue region, the temperature spiked
to a maximum of about 55 degrees Celsius, then gradually cooled to
about 32 degrees Celsius 100 seconds after the start of the
treatment. The 60 W porcine muscle started at about 24 degrees
Celsius, and over the course of 20 seconds (between the 40 and 60
second marks) of heating through three passes of the cylindrical
transduction element 281 over the target tissue region, the
temperature spiked to a maximum of about 59 degrees Celsius, then
gradually cooled to about 40 degrees Celsius about 80 seconds after
the start of the treatment.
[0180] FIG. 18 is a photograph of the porcine muscle after
treatment confirming line and plane heating. In one embodiment, the
coagulation was dependent on time-off between lines, time-off
between passes, and number of passes. Slower temperature rise than
thermal coagulation points. FIG. 19 is a cross-section cut through
the porcine muscle in FIG. 18 showing a linear thermal treatment
zone. FIG. 20 is an orthogonal cross-section cut through the
porcine muscle in FIG. 19 showing a planar thermal treatment
zone.
EXAMPLE 2
[0181] The following example is intended to be a non-limiting
embodiment of the invention.
[0182] As illustrated at FIGS. 28-30, it was experimentally
verified that an embodiment of a partially coated transducer 600
comprising a cylindrical transduction element 281, which was
applied to a simulated target tissue, formed a localized, linear
thermal treatment zone (TTZ 550) in a targeted focal area 552. The
partially coated transducer 600 includes a first coated region 287
that fully plates the concave surface 282 of the cylindrical
transduction element and at least a second coated region 287 that
partially plates the convex surface 283 of the cylindrical
transduction element. Both the first and the second coated regions
287 of the partially coated transducer 600 are plated with silver.
In the experiment, the single cylindrical transduction element 281
was constructed with a radius and focal depth of 15 mm. The size of
the cylindrical transduction element 281 was 20 mm (azimuth) by 17
mm (elevation). The cylindrical transduction element 281 had an
opening 285 in the center of 4 mm in diameter.
[0183] In FIGS. 28, 29 and 30, treatment profiles were plotted
based on theoretical performance with a cylindrical transduction
element 281. The theoretical performance is proportional the
thermal heating at the specified depth. The software simulated
experiment reflects the theoretical performance of the 15 mm
partially coated transducer 600, showing a consistent linear
thermal treatment zone 550 at the 15 mm depth.
EXAMPLE 3
[0184] The following example is intended to be a non-limiting
embodiment of the invention.
[0185] Multiple in-vivo porcine studies and multiple cadaver
studies were conducted to evaluate various embodiments of hardware
to perform bulk heating treatments. Early studies focused on
specifying and improving the instrumentation necessary to measure
subdermal temperatures. In some embodiments, insulated wire
thermocouples were placed at focal and subfocal depths by snaking
the thermocouple through a needle-bored hole in the skin and
verifying the depth with a Siemens s2000 ultrasound device.
Temperature profiles were collected using a high sampling DAQ card.
Once the measurement setup was defined, a replicated 3-factor
3-level design of experiments was performed in the in-vivo porcine
model to determine energy settings that could safely reach
isoeffective dosages without causing skin surface damage. In one
embodiment, a mean temperature differential of 10 degrees Celsius
was observed, with a mean focal heating rate of .about.1.2 degrees
Celsius/pass. Safe heating rates appear to be similar across
transducer.
[0186] A thermal dosage study was performed in the in-vivo porcine
model after safe heating rates were determined. The study
demonstrated an embodiment of the system is capable of reaching
isoeffective dosages such as 47 degrees Celsius for 3 minutes, 48
degrees Celsius for 1 minute, and 50 degrees Celsius for 1 minute
without exceeding 41 degrees Celsius on the skin surface. In some
embodiments, use of higher temperature, shorter exposure time
treatments may have the potential to overshoot the target
temperature and could overheat the skin surface. In various
embodiments, the longer it takes to perform an isoeffective dose,
the more heat diffuses to the surrounding tissue and less selective
the treatment becomes with depth. Additionally, the longer the
isoeffective exposure time, the more impractical the treatment
becomes from an operator and ergonomics point of view. For these
reasons, in some embodiments, use of higher isoeffective
temperatures and shorter exposure times were preferred.
[0187] In-vivo porcine tests were conducted to determine if the
candidate treatment settings for submental could cause adverse
surface skin effects. The animals procured for these studies were
light skinned, 120-140 pound castrated male Yucatan miniature pigs,
selected due to its skin characteristics being similar to that of
human tissue. Skin surface data was evaluated by monitoring the
animal for evidence of erythema, edema, and contusion on the skin
surface after treatment. Photographs of each treatment area were
taken prior to and following treatment (Cannon G9 and Cannon VIXIA
IIF 510). In one embodiment, a thermal dosage study using a
cylindrical element transducer was performed on in-vivo porcine
models. In several embodiments, test sites were able to achieve a
significant temperature differential between the focus tissue site
and the skin surface without causing damage to the skin surface.
FIG. 46 shows the temperature profiles from an embodiment of an
in-vivo porcine model treatment in which the temperature profile
reached 50 degrees Celsius for several seconds without the skin
surface exceeding 41 degrees Celsius, and shows a temperature
differential of as much as 15 degrees Celsius between the focus
tissue site and the skin surface. The temperature change accrued
from a single pass of treatment is sufficiently small
(approximately 0.9 degrees Celsius/pass or 0.13 degrees
Celsius/sec) to perform corrective action and maintain a target
temperature within +/-1 degrees Celsius. A modified 3-factor
3-level design of experiments was performed in the in-vivo porcine
model to determine a range of energy settings that could safely
reach the isoeffective dosages temperatures shown in FIG. 42. The
settings, according to various embodiments, are tabulated in the
table at FIG. 47. The Design of Experiments (DOE) tests an acoustic
power range of 10-20 W, exposure times of 20-40 ms, and spacings in
the range of 0.1-0.3 mm. FIG. 48 shows an embodiment of a treatment
setting that was able to achieve a relatively high thermal dosage
at the focus with little to no dose or temperature increase at the
skin surface. The focus achieves a thermal dose of 100 equivalent
minutes (red-dashed line) at T=43 degrees Celsius on the 24th pass,
which corresponds to a theoretical survival fraction of 1%
according to FIG. 42. In various embodiments, similar temperature
rises and heating rates were achieved at the focus and surface
across various embodiments of transducers for treatments that did
not cause significant skin surface damage. A mean temperature
differential of 10 degrees Celsius was observed, with a mean focal
heating rate of .about.1.2 degrees Celsius/pass. The largest
temperature differential between the focus and the skin was
achieved by the 3.5 MHz, 22 mm width, 6.0 depth design which had an
average difference of 12 degrees Celsius across treatments. Since
the heating rates that produce little to no surface effects are
similar across transducer, the 3.5 MHz, 22 mm width, 6.0 mm depth
transducer was selected to be assessed in a thermal dosage
study.
[0188] In various embodiments, thermal dosage studies were
performed on in-vivo porcine and cadaver models to determine safe
isoeffective dosages, and the geometry of adipocyte death through
histological evaluation. The Table at FIG. 49 tabulates the target
time-temperature exposures to achieve different levels of adipocyte
death. According to the empirical data in FIG. 42, Site 2 and 5
should achieve little to no adipocyte death. Sites 3, 6 and 7
should achieve a high degree of adipocyte death. Sites 1 and 4 are
within the transition region and should achieve a moderate amount
of adipocyte death. The table at FIG. 50 lists the energy settings
used to approach each isoeffective dose using a 3.5 MHz, 22 mm
width, 6.0 mm depth transducer. In various embodiments, treatments
were active for 2-3 minutes with 20-30 pulses to reach the target
temperature with a 1 degrees Celsius/pass ramp followed by
maintenance pulses ever 3-5 seconds. A few test sites showed mild
surface effects the day of treatment, only to become more
pronounced as the injury rose to the skin surface. FIG. 51 shows
one site that was treated aggressively for the purpose of
coagulating tissue for histological control through overdosing. In
the embodiment in FIG. 51, the dimension of the lesion represents a
an example of the spread of thermal energy, measuring
12.6.times.19.9 mm on the skin surface with a depth of edema that
can be detected up to 12 mm from the skin surface. A visual
representation of the time-temperature goals listed in the table at
FIG. 49 is shown in FIG. 52 (triangle marks), with six isoeffective
dosages achieved in the lab are overlayed in FIG. 52 (square
marks). Two of these isoeffective dosages fall in the coagulative
region, two fall in the transition region, and two in the
hyperthermia region.
[0189] Some embodiments and the examples described herein are
examples and not intended to be limiting in describing the full
scope of compositions and methods of these invention(s). Equivalent
changes, modifications and variations of some embodiments,
materials, compositions and methods can be made within the scope of
the embodiments herein. In various embodiments, a device or method
can combine features or characteristics of any of the embodiments
disclosed herein.
[0190] While the invention is susceptible to various modifications,
and alternative forms, specific examples thereof have been shown in
the drawings and are herein described in detail. It should be
understood, however, that the invention is not to be limited to the
particular forms or methods disclosed, but to the contrary, the
invention is to cover all modifications, equivalents, and
alternatives falling within the spirit and scope of the various
embodiments described and the appended claims. Any methods
disclosed herein need not be performed in the order recited. The
methods disclosed herein include certain actions taken by a
practitioner; however, they can also include any third-party
instruction of those actions, either expressly or by implication.
For example, actions such as "coupling an ultrasound probe to a
skin surface" include "instructing the coupling of an ultrasound
probe to a skin surface." The ranges disclosed herein also
encompass any and all overlap, sub-ranges, and combinations
thereof. Language such as "up to," "at least," "greater than,"
"less than," "between," and the like includes the number recited.
Numbers preceded by a term such as "about" or "approximately"
include the recited numbers. For example, "about 25 mm" includes
"25 mm" The terms "approximately", "about", and "substantially" as
used herein represent an amount or characteristic close to the
stated amount or characteristic that still performs a desired
function or achieves a desired result. For example, the terms
"approximately", "about", and "substantially" may refer to an
amount that is within less than 10% of, within less than 5% of,
within less than 1% of, within less than 0.1% of, and within less
than 0.01% of the stated amount or characteristic.
* * * * *