U.S. patent application number 11/623705 was filed with the patent office on 2007-10-11 for apparatus for delivering high intensity focused ultrasound energy to a treatment site internal to a patient's body.
This patent application is currently assigned to Mirabilis Medica, Inc.. Invention is credited to Michael J. Connolly, Michael Lau, Alexander Lebedev, Shahram Vaezy.
Application Number | 20070239011 11/623705 |
Document ID | / |
Family ID | 38288182 |
Filed Date | 2007-10-11 |
United States Patent
Application |
20070239011 |
Kind Code |
A1 |
Lau; Michael ; et
al. |
October 11, 2007 |
APPARATUS FOR DELIVERING HIGH INTENSITY FOCUSED ULTRASOUND ENERGY
TO A TREATMENT SITE INTERNAL TO A PATIENT'S BODY
Abstract
An apparatus for delivering HIFU energy may include a probe with
a plurality of leaves that provide a bowl-shaped HIFU therapy
transducer. In once case, pins may slide within grooves in the
leaves to deploy the leaves. In another case, spines may be
configured to slide in a channel defined in each leaf. In other
cases, a spring or a shape memory alloy may be used to deploy the
leaves. In another implementation, a probe may be fitted with a
flexible material that couples the HIFU therapy transducer to the
probe and allows the transducer to be drawn to the side of the
probe for insertion. In another implementation, a probe may have
one or more inflatable bladders that form the HIFU therapy
transducer. In yet another implementation, a probe may have an
imaging component and a HIFU therapy transducer disposed thereon
that rotate, as a unit, about a hinge.
Inventors: |
Lau; Michael; (Edmonds,
WA) ; Vaezy; Shahram; (Seattle, WA) ; Lebedev;
Alexander; (Seattle, WA) ; Connolly; Michael J.;
(Seattle, WA) |
Correspondence
Address: |
CHRISTENSEN, O'CONNOR, JOHNSON, KINDNESS, PLLC
1420 FIFTH AVENUE, SUITE 2800
SEATTLE
WA
98101-2347
US
|
Assignee: |
Mirabilis Medica, Inc.
Seattle
WA
|
Family ID: |
38288182 |
Appl. No.: |
11/623705 |
Filed: |
January 16, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60758797 |
Jan 13, 2006 |
|
|
|
Current U.S.
Class: |
600/439 ;
601/2 |
Current CPC
Class: |
A61N 2007/0078 20130101;
A61N 7/022 20130101; A61B 1/00165 20130101; A61B 8/12 20130101;
A61B 8/445 20130101; A61B 2017/4216 20130101 |
Class at
Publication: |
600/439 ;
601/2 |
International
Class: |
A61H 1/00 20060101
A61H001/00; A61B 8/00 20060101 A61B008/00 |
Claims
1. An apparatus for delivering high intensity focused ultrasound
(HIFU) energy to a treatment site internal to a patient's body,
comprising: an elongate probe having a proximal end and a distal
end, the proximal end having a section adapted for positioning the
distal end of the probe at a desired location within the patient's
body; wherein the distal end of the probe has a HIFU therapy
transducer coupled thereto, the HIFU therapy transducer comprising
a plurality of leaves, each leaf having a proximal end, a distal
end, and a deployment mechanism, wherein the proximal end of each
leaf is coupled to the distal end of the probe, each leaf further
having a front surface adapted to direct HIFU energy to the
treatment site when the probe is inserted in the patient's body and
the deployment mechanism is activated; wherein, when activated, the
deployment mechanism is configured to deploy the leaves by
directing the distal end of the leaves in a radially outward
direction, the leaves thus deployed collectively providing a
bowl-shaped HIFU therapy transducer having an outer edge with a
diameter that is larger than the diameter of the probe and an
aperture of a size sufficient to direct therapeutic HIFU energy to
the treatment site; and wherein, to facilitate insertion of the
probe in the patient's body, the plurality of leaves are configured
to collapse when the deployment mechanism is not activated, the
collapsed leaves occupying a space having a diameter smaller than
the diameter of the outer edge of the HIFU therapy transducer when
the leaves are deployed.
2. The apparatus of claim 1, wherein the elongate probe includes a
sleeve disposed around a shaft, the sleeve having a proximal end, a
distal end, and a longitudinal axis extending therebetween, and the
shaft being configured to slide within the sleeve from a retracted
position to an extended position along the longitudinal axis.
3. The apparatus of claim 2, wherein the proximal end of each leaf
is coupled to a distal end of the shaft, wherein the deployment
mechanism of each leaf includes a pin coupled to the sleeve, the
pin being configured to slide within a groove defined in the leaf,
and wherein activation of the deployment mechanism comprises
sliding the shaft within the sleeve toward the extended position,
such activation causing each leaf to be pushed outward from the
distal end of the sleeve, the pin sliding within the groove in each
respective leaf to direct the distal end of the leaf radially
outward to a desired position to provide the bowl-shaped HIFU
transducer.
4. The apparatus of claim 3, wherein the leaves are held within the
sleeve next to the shaft when the deployment mechanism is not
activated and the shaft is in the retracted position.
5. The apparatus of claim 4, wherein at least a portion of a leaf
in the plurality of leaves is configured to overlap at least a
portion of another leaf when the leaves are held within the
sleeve.
6. The apparatus of claim 3, wherein the distal end of the shaft
extends beyond the distal end of the sleeve when the shaft is in
the extended position, thus exposing the distal end of the shaft
outside the sleeve.
7. The apparatus of claim 3, wherein the pin includes a detent
configured to secure the pin within the groove in the respective
leaf.
8. The apparatus of claim 3, wherein the groove in each leaf is
defined at an angle relative to the longitudinal axis of the
sleeve.
9. The apparatus of claim 2, wherein the shaft includes an actuator
configured to drive the shaft between the retracted and extended
positions.
10. The apparatus of claim 2, wherein the proximal end of each leaf
is coupled to a distal end of the sleeve, wherein the deployment
mechanism of each leaf includes a spine coupled to the shaft, the
spine being configured to slide within the sleeve into a channel
defined in the leaf, and wherein activation of the deployment
mechanism comprises sliding the shaft within the sleeve toward the
extended position, such activation causing the spine for each leaf
to be pushed into the channel of the respective leaf to direct the
distal end of the leaf radially outward to a desired position to
provide the bowl-shaped HIFU transducer.
11. The apparatus of claim 10, wherein the spine for each leaf is
held within the sleeve when the deployment mechanism is not
activated and the shaft is in the retracted position.
12. The apparatus of claim 10, wherein the leaves, when collapsed,
are capable of being grouped together to occupy a space having a
diameter that is equal to or smaller than the diameter of the
sleeve.
13. The apparatus of claim 2, wherein the proximal end of each leaf
is coupled to a distal end of the shaft, wherein the deployment
mechanism of each leaf includes a spring having a first end coupled
to the shaft and a second end disposed within the leaf, and wherein
activation of the deployment mechanism comprises sliding the shaft
within the sleeve toward the extended position, such activation
causing each leaf to be pushed outward from the distal end of the
sleeve, the second end of the spring in each leaf being configured
to bias the distal end of the respective leaf in a radially outward
direction to a desired position to provide the bowl-shaped HIFU
transducer when the shaft is in the extended position.
14. The apparatus of claim 1, wherein the distal end of the probe
further has an imaging component coupled thereto, the imaging
component being adapted to produce an image of a portion of the
patient's body that includes the treatment site to help guide the
delivery of HIFU energy to the treatment site.
15. The apparatus of claim 14, wherein the imaging component is
configured to use reflected ultrasound energy to produce the image
of the portion of the patient's body.
16. The apparatus of claim 14, wherein the imaging component is
configured to use reflected light to produce the image of the
portion of the patient's body.
17. The apparatus of claim 14, wherein the image further includes a
portion of the HIFU therapy transducer to assist in positioning the
HIFU therapy transducer within the patient's body and in monitoring
HIFU therapy at the treatment site.
18. The apparatus of claim 1, wherein the HIFU therapy transducer
is coupled to the distal end of the probe via a hinge having an
axis about which the transducer can rotate to aim the HIFU energy
toward the treatment site.
19. The apparatus of claim 1, wherein at least a portion of the
leaves are formed of an energy-activated shape memory alloy and the
deployment mechanism includes a coupling of the shape memory alloy
to an energy source, wherein activation of the deployment mechanism
comprises delivering energy from the energy source to the shape
memory alloy of each leaf to cause the shape memory alloy to take a
predefined shape in which the distal end of the leaves are directed
radially outward to provide the bowl-shaped HIFU transducer.
20. The apparatus of claim 19, wherein the portion of the leaves
formed of a shape memory alloy is configured as a spine in each
leaf.
21. The apparatus of claim 1, further comprising an active element
disposed on the front surface of at least one of the leaves,
wherein the active element is operable to generate the HIFU energy
that is directed to the treatment site.
22. The apparatus of claim 1, wherein the front surface of at least
one of the leaves is configured to reflect HIFU energy toward the
treatment site, said HIFU energy being received from a source that
is remote from the leaf.
23. An apparatus for delivering high intensity focused ultrasound
(HIFU) energy to a treatment site internal to a patient's body,
comprising: an elongate probe having a proximal end, a distal end,
and a longitudinal axis extending therebetween, the proximal end of
the probe having a section adapted for positioning the distal end
of the probe at a desired location within the patient's body;
wherein the distal end of the probe is fitted with a flexible
material that couples a HIFU therapy transducer to the probe, the
HIFU therapy transducer having a major axis across its face and an
aperture of a size sufficient to direct therapeutic HIFU energy to
the treatment site, the flexible material having a resting state in
which the transducer is deployed in a therapy position wherein the
major axis of the transducer is non-parallel to the longitudinal
axis of the probe; wherein, to facilitate insertion of the probe in
the patient's body, the flexible material is configured to stretch
and allow the transducer to be drawn to the side of the probe to an
insertion position wherein the major axis of the transducer is
generally parallel to the longitudinal axis of the probe, the
flexible material exhibiting a bias to return toward its resting
state after the probe has been inserted in the patient's body and
the transducer has been released.
24. The apparatus of claim 23, further comprising an actuator
coupled to the transducer that can be manipulated to draw the
transducer to the side of the probe and to deploy the transducer to
the therapy position.
25. The apparatus of claim 23, wherein the distal end of the probe
further includes an imaging component adapted for producing an
image of a portion of the patient's body that includes the
treatment site to help guide the delivery of HIFU energy to the
treatment site.
26. The apparatus of claim 25, wherein the imaging component is
configured to use reflected ultrasound energy to produce the image
of the portion of the patient's body.
27. The apparatus of claim 25, wherein the imaging component is
configured to use reflected light to produce the image of the
portion of the patient's body.
28. The apparatus of claim 25, wherein the image further includes a
portion of the HIFU therapy transducer to assist in positioning the
HIFU therapy transducer within the patient's body and in monitoring
HIFU therapy at the treatment site.
29. The apparatus of claim 23, wherein the flexible material is
comprised of a resilient non-metal material.
30. The apparatus of claim 23, wherein the flexible material is
comprised of a shape memory alloy having a stretched state or
resting state dependent on energy activation of the alloy.
31. The apparatus of claim 23, further comprising an active element
disposed on the HIFU therapy transducer, wherein the active element
is operable generate the HIFU energy that is directed to the
treatment site.
32. The apparatus of claim 23, wherein the HIFU therapy transducer
is configured to reflect HIFU energy toward the treatment site,
said HIFU energy being received from a source that is remote from
the transducer.
33. An apparatus for delivering high intensity focused ultrasound
(HIFU) energy to a treatment site internal to a patient's body,
comprising: an elongate probe having a proximal end and a distal
end, the proximal end of the probe having a section adapted for
positioning the distal end of the probe at a desired location
within the patient's body; wherein the distal end of the probe is
fitted with a flexible material having one or more inflatable
bladders that, when inflated, provide a HIFU therapy transducer
having an aperture of a size sufficient to direct therapeutic HIFU
energy to the treatment site, the inflatable bladders extending
radially outward from the distal end of the probe, and wherein, to
facilitate insertion of the probe in the patient's body, the
bladders are not inflated until after the probe is inserted in the
patient's body; the flexible material further having a front
surface adapted to direct HIFU energy to the treatment site when
the probe is inserted in the patient's body and the bladders are
inflated, and wherein, when inflated, the bladders provide lateral
support to the HIFU therapy transducer and the transducer has an
aperture that is larger than the diameter of the probe.
34. The apparatus of claim 33, wherein the bladders comprise one or
more inflatable channels that extend radially outward from the
distal end of the probe, and wherein the front face of the flexible
material extends between the inflatable channels.
35. The apparatus of claim 34, wherein the inflatable channels
terminate in an inflatable ring that forms an outer edge of the
HIFU therapy transducer.
36. The apparatus of claim 35, wherein when inflated, the diameter
of the ring is larger than the diameter of the probe.
37. The apparatus of claim 33, further comprising an active element
disposed on the front surface of the flexible material, wherein the
active element is operable generate the HIFU energy that is
directed to the treatment site.
38. The apparatus of claim 33, wherein the front surface of the
flexible material is configured to reflect HIFU energy toward the
treatment site, said HIFU energy being received from a source that
is remote from the flexible material.
39. The apparatus of claim 33, wherein the distal end of the probe
further includes an imaging component adapted for producing an
image of a portion of the patient's body that includes the
treatment site to help guide the delivery of HIFU energy to the
treatment site.
40. The apparatus of claim 39, wherein the imaging component is
configured to use reflected ultrasound energy to produce the image
of the portion of the patient's body.
41. The apparatus of claim 39, wherein the imaging component is
configured to use reflected light to produce the image of the
portion of the patient's body.
42. The apparatus of claim 39, wherein the image further includes a
portion of the HIFU therapy transducer to assist in positioning the
HIFU therapy transducer within the patient's body and in monitoring
HIFU therapy at the treatment site.
43. The apparatus of claim 33, wherein the bladders, when not
inflated, occupy a space having a diameter smaller than the
diameter of the HIFU therapy transducer when the bladders are
inflated.
44. The apparatus of claim 33, wherein the bladders are inflated
using a fluid that is circulated to and from the bladders to
control a temperature of the HIFU therapy transducer and tissue
adjacent to the HIFU therapy transducer when the probe is inserted
into the patient.
45. An apparatus for delivering image-guided high intensity focused
ultrasound (HIFU) energy to a treatment site internal to a
patient's body, comprising: an elongate probe having a proximal
end, a distal end, and a longitudinal axis extending therebetween,
the proximal end of the probe having a section adapted for
positioning the distal end of the probe at a desired location
within the patient's body; a support structure having an imaging
component and a HIFU therapy transducer disposed thereon; and a
hinge connecting the support structure to the distal end of the
probe, wherein the imaging component is adapted for producing an
image of a portion of the patient's body that includes the
treatment site, wherein the HIFU therapy transducer has an aperture
of a size sufficient to direct therapeutic HIFU energy to the
treatment site and is disposed on the support structure in defined
relation to the imaging component, and wherein, to facilitate
insertion of the probe in the patient's body, the support structure
is capable of rotating about the hinge to an insertion position
generally parallel to the longitudinal axis of the probe, and after
insertion of the probe in the patient's body, the support structure
is capable of rotating about the hinge to a position non-parallel
to the longitudinal axis of the probe, the hinge providing an
articulation that enables the imaging and therapy transducers as a
unit to be positioned relative to the treatment site in the
patient's body.
46. The apparatus of claim 45, wherein the HIFU therapy transducer
is bowl-shaped and the imaging component is disposed within the
interior of the therapy transducer.
47. The apparatus of claim 45, wherein the imaging component is
disposed on the support structure to the exterior of the HIFU
therapy transducer.
48. The apparatus of claim 45, wherein the imaging component is
configured to use reflected ultrasound energy to produce the image
of the portion of the patient's body.
49. The apparatus of claim 48, wherein the imaging and delivery of
HIFU therapy are performed using same transducer.
50. The apparatus of claim 45, wherein the imaging component is
configured to use reflected light to produce the image of the
portion of the patient's body.
51. The apparatus of claim 45, wherein the image produced by the
imaging component includes a portion of the HIFU therapy transducer
to assist in positioning the HIFU therapy transducer within the
patient's body and in monitoring HIFU therapy at the treatment
site.
52. The apparatus of claim 45, wherein the dimension of the therapy
transducer in its insertion position and measured perpendicular to
the longitudinal axis of the probe is smaller than the dimension of
the transducer measured parallel to the longitudinal axis.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional
Application No. 60/758,797, titled TRANSVAGINAL IMAGE-GUIDED HIGH
INTENSITY FOCUSED ULTRASOUND (HIFU) DEVICES AND METHODS FOR THERAPY
TO THE FEMALE REPRODUCTIVE SYSTEM, filed Jan. 13, 2006.
FIELD OF THE INVENTION
[0002] The present application is directed to apparatus that
provide therapeutic treatment of internal pathological conditions
using high-intensity focused ultrasound energy, and more
particularly, to providing improved apparatus for insertion and
deployment of a HIFU therapy transducer, with or without an imaging
component.
BACKGROUND
[0003] Delivery of high-intensity focused ultrasound (HIFU) energy
has emerged as a precise, non-surgical, minimally-invasive
treatment for benign and malignant tumors. (See, e.g., S. Vaezy, M.
Andrew, P. Kaczkowski et al., "Image-guided acoustic therapy,"
Annu. Rev. Biomed. Eng. 3, 375-90 (2001)). At focal intensities 4-5
orders of magnitude greater than diagnostic ultrasound (typically
about 0.1 W/cm.sup.2), HIFU (typically about 1000-10,000
W/cm.sup.2) can induce lesions or tissue necrosis at a small
location deep in tissue while leaving tissue between the ultrasound
source and focus unharmed. Tissue necrosis is a result of focal
temperatures typically exceeding 70.degree. C. which can occur with
relatively short intervals of HIFU exposure. HIFU is currently
being used clinically for the treatment of prostate cancer and
benign prostatic hyperplasia, as well as malignant bone tumor and
soft tissue sarcoma. Clinical trials for HIFU treatment of breast
fibroadenomas and various stage 4 primary and metastatic cancer
tumors of the kidney and liver are underway.
[0004] Uterine fibroid, as an example of a pathological condition
in the female pelvis, is the most common pelvic tumor in women of
reproductive age. Uterine fibroids, or leiomyoma, are benign tumors
that cause abnormal uterine bleeding. The incidence of fibroids has
been estimated to be 20-25% in women in their reproductive years,
although autopsy studies show an incidence upwards of 75%.
Approximately 1/3 of these women will have a tumor that is
symptomatic requiring treatment. HIFU energy delivered using a
transvaginal transducer can provide a feasibly minimally-invasive
treatment for uterine fibroids.
[0005] Further development of HIFU devices for providing therapy in
obstetrics and gynecology, as well as other fields of medical
endeavor, is desired. In particular, improved devices are needed
which can provide noninvasive therapeutic treatment of uterine
fibroids, recurrent leiomyosarcoma, and other solid tumors of the
uterine corpus and cervix, as well as abnormal uterine bleeding
conditions and many other obstetric and gynecologic pathological
conditions.
[0006] A major challenge for transvaginal HIFU treatment of uterine
pathologies is the deployment of a HIFU therapy transducer having
an aperture of adequate size. In general, devices with a larger
HIFU aperture tend to optimize the focal length of the HIFU beam
and the therapeutic effect of the focused ultrasound energy.
However, the size and configuration of the HIFU aperture are
generally limited by the size and shape of the vaginal cavity and
the location of the cervix and vaginal fornices.
[0007] Even more challenging is the issue of transvaginal insertion
of a HIFU therapy transducer through the rather narrow vaginal
introitus. The present application addresses the problems of
insertion of a probe with a HIFU transducer through small passages,
such as the vaginal introitus, and deployment of the HIFU
transducer, with or without an imaging component, within a body
cavity in order to achieve optimal imaging and HIFU therapeutic
effects.
BRIEF SUMMARY
[0008] The following description briefly summarizes certain aspects
of the disclosure herein. This summary is not intended to identify
all features or implementations disclosed herein, nor is it
intended to identify key features or otherwise be used to define
the scope of the invention claimed hereafter.
[0009] In one implementation, an apparatus for delivering high
intensity focused ultrasound (HIFU) energy to a treatment site
internal to a patient's body may include an elongate probe with a
HIFU therapy transducer coupled thereto. The HIFU therapy
transducer is comprised of a plurality of leaves, each leaf having
a front surface adapted to direct HIFU energy to a treatment site
when the probe is inserted in a patient's body and a deployment
mechanism is activated. When activated, the deployment mechanism is
configured to deploy the leaves by directing the leaves in a
radially outward direction. The leaves thus deployed collectively
provide a bowl-shaped HIFU therapy transducer having an outer edge
with a diameter that is larger than the diameter of the probe. To
facilitate insertion of the probe in the patient's body, the
plurality of leaves are configured to collapse when the deployment
mechanism is not activated. The collapsed leaves occupy a space
having a diameter smaller than the diameter of the outer edge of
the HIFU therapy transducer when the leaves are deployed.
[0010] In one aspect, the probe may include a sleeve disposed
around a shaft. The shaft is configured to slide within the sleeve
from a retracted position to an extended position. Each leaf is
coupled to a distal end of the shaft, and the deployment mechanism
includes a pin coupled to the sleeve that slides within a groove
defined in each leaf. Activation of the deployment mechanism
comprises sliding the shaft within the sleeve toward the extended
position, which causes each leaf to be pushed outward from the
distal end of the sleeve. As the pin slides within the groove in
each respective leaf, the distal end of the leaf is directed
radially outward to a desired position to provide the bowl-shaped
HIFU transducer. An actuator, such as a button connected to the
shaft, may be configured to help drive the shaft between the
retracted and extended positions.
[0011] In another aspect, each leaf may be coupled to a distal end
of the sleeve, wherein the deployment mechanism of each leaf
includes a spine coupled to the shaft. The spines are configured to
slide within the sleeve into a channel defined in the leaf.
Activation of the deployment mechanism comprises sliding the shaft
within the sleeve toward the extended position, thus causing the
spine for each leaf to be pushed into the channel of the respective
leaf which directs the leaf radially outward. When the spines are
retracted in the sleeve and the leaves are collapsed, the leaves
are capable of being grouped together to occupy a space having a
diameter that is equal to or smaller than the diameter of the
sleeve.
[0012] In another aspect, the proximal end of each leaf may be
coupled to a distal end of the shaft, wherein the deployment
mechanism includes a spring having a first end coupled to the shaft
and a second end disposed within the leaf. Activation of the
deployment mechanism comprises sliding the shaft within the sleeve
toward the extended position. As each leaf is pushed outward from
the sleeve, the second end of the spring in each leaf biases the
distal end of the leaf in a radially outward direction to provide
the bowl-shaped HIFU transducer.
[0013] In another aspect, a portion of each leaf may be formed of
an energy-activated shape memory alloy. The deployment mechanism
includes a coupling of the shape memory alloy to an energy source.
Activation of the deployment mechanism comprises delivering energy
from the energy source to the shape memory alloy of each leaf to
cause the shape memory alloy to take a predefined shape in which
the distal end of the leaves are directed radially outward to
provide the bowl-shaped HIFU transducer. The portion of the leaves
formed of a shape memory alloy may be configured as a spine in each
leaf.
[0014] The HIFU therapy transducer may also be coupled to the probe
via a hinge, enabling the HIFU transducer to rotate about the hinge
to help aim the HIFU energy toward the treatment site.
[0015] In another implementation, an apparatus for HIFU energy to a
treatment site internal to a patient's body may include an elongate
probe fitted with a flexible material that couples a HIFU therapy
transducer to the probe. For reference purposes, the HIFU therapy
transducer may be considered as having a major axis across its
face. In a resting state, the flexible material deploys the
transducer in a therapy position wherein the major axis of the
transducer is non-parallel to the longitudinal axis of the probe.
To facilitate insertion of the probe in the patient's body, the
flexible material is configured to stretch and allow the transducer
to be drawn to the side of the probe to an insertion position where
the major axis of the transducer is generally parallel to the
longitudinal axis of the probe. After insertion, the transducer is
released and the flexible material returns toward its resting
state, thus deploying the transducer for therapy delivery. If
desired, an actuator may be coupled to the transducer and
manipulated to draw the transducer to the side of the probe for
insertion and/or removal of the probe from the patient. The
actuator may also be manipulated to deploy the transducer for
therapy delivery after the probe has been inserted into the
patient.
[0016] In another implementation, an apparatus for delivering HIFU
energy to a treatment site internal to a patient's body may include
an elongate probe fitted with a flexible material that has one or
more inflatable bladders. The bladders extend radially outward from
the distal end of the probe. When inflated, the bladders form a
HIFU therapy transducer having an aperture that is larger than the
diameter of the probe. The bladders are not inflated until after
the probe is inserted in the patient's body. When not inflated, the
bladders occupy a space having a diameter smaller than the diameter
of the HIFU therapy transducer when otherwise inflated. The
flexible material is configured with a front surface that is
adapted to direct HIFU energy to the treatment site when the
bladders are inflated.
[0017] In one aspect, the bladders may comprise one or more
inflatable channels that extend radially outward from the distal
end of the probe, wherein the front face of the flexible material
extends between the inflatable channels. The inflatable channels
may terminate in an inflatable ring that forms an outer edge of the
HIFU therapy transducer. When inflated, the diameter of the ring is
larger than the diameter of the probe.
[0018] In another implementation, an apparatus for delivering
image-guided HIFU energy to a treatment site internal to a
patient's body may include a probe with a support structure having
an imaging component and a HIFU therapy transducer disposed
thereon. A hinge is used to connect the support structure to the
distal end of the probe. The imaging component is preferably
adapted for producing an image of a portion of the patient's body
that includes the treatment site, while the HIFU therapy transducer
directs HIFU energy to the treatment site. The HIFU therapy
transducer is disposed on the support structure in defined relation
to the imaging component.
[0019] To facilitate insertion of the probe in a patient's body,
the support structure is capable of rotating about the hinge to a
position generally parallel to the longitudinal axis of the probe.
After insertion of the probe, the support structure is capable of
rotating about the hinge to a position non-parallel to the
longitudinal axis of the probe. The hinge thus provides an
articulation that enables the imaging and therapy transducers as a
unit to be positioned relative to the treatment site in the
patient's body.
[0020] In one aspect, the HIFU therapy transducer may be
bowl-shaped, with the imaging component disposed in the interior of
the therapy transducer. In another aspect, the imaging component
may be disposed on the support structure to the exterior of the
HIFU therapy transducer.
[0021] In the foregoing implementations, an imaging component
included with the probe may be configured to use reflected
ultrasound energy to produce an image of a portion of the patient's
body. Alternatively, or in addition, the imaging component may be
configured to use reflected light to produce an image of a portion
of the patient's body. Still another alternative is that the
imaging component consists of the same transducer as used to
produce the HIFU energy. In some cases, the image produced by the
imaging component may include a portion of the HIFU therapy
transducer and/or the focal point of the HIFU energy within the
tissue. The image obtained by the imaging component may assist in
positioning the HIFU therapy transducer within the patient's body
and in monitoring the delivery and effects of the HIFU therapy at
the treatment site.
DESCRIPTION OF THE DRAWINGS
[0022] The foregoing aspects and many of the attendant advantages
of this invention will become more readily appreciated as the same
become better understood by reference to the following detailed
description, when taken in conjunction with the accompanying
drawings, wherein the drawings are described as follows:
[0023] FIG. 1 illustrates in section view a possible environment in
which an implementation of the present invention may be used for
treatment of pathologies of the female reproductive system;
[0024] FIG. 2 illustrates the implementation of the apparatus
depicted in FIG. 1;
[0025] FIGS. 3A-3C illustrate an implementation of the invention
having a retractable HIFU therapy transducer;
[0026] FIG. 4 illustrates a side section view of the implementation
shown in FIGS. 3A-3C;
[0027] FIGS. 5A and 5B illustrate an implementation of the
invention with a collapsible HIFU therapy transducer;
[0028] FIGS. 6A and 6B illustrate an implementation of the
invention with a flexible material coupling a HIFU therapy
transducer to a probe;
[0029] FIGS. 7A and 7B illustrate an implementation of the
invention having a HIFU therapy transducer with an inflatable
support;
[0030] FIG. 8 illustrates another implementation of a probe having
a HIFU therapy transducer with an inflatable support;
[0031] FIGS. 9A and 9B illustrate further aspects of an
implementation of the invention with an imaging component and HIFU
therapy transducer as a unit configured to rotate about a hinge,
where the imaging component is disposed within the interior of the
HIFU therapy transducer; and
[0032] FIGS. 10A and 10B illustrate further aspects of an
implementation of the invention similar to the implementation shown
in FIGS. 9A and 9B, where the imaging component is disposed to the
exterior of the HIFU therapy transducer.
DETAILED DESCRIPTION
[0033] Disclosed herein are implementations of an apparatus
designed for delivering high-intensity focused ultrasound (HIFU)
energy to a treatment site internal to a patient's body. The
implementations herein facilitate the insertion of a probe with a
HIFU therapy transducer through a narrow opening to various
cavities of the human body. These implementations can be applied to
body orifices and cavities including, but not limited to, the
urinary tract, gastrointestinal tract, cardiovascular system,
respiratory system, and reproductive system, as well as through
endoscopes or laparoscopes for minimally-invasive surgery in
various parts of the body. For purposes of illustration herein,
various implementations are shown and discussed in the context of
providing HIFU therapy in the female reproductive system.
[0034] FIG. 1 illustrates an implementation of the invention,
wherein a probe 1 with a HIFU therapy transducer 2 has been
introduced into the vaginal cavity of a female patient 3. In this
particular implementation, the HIFU therapy transducer is designed
for coupling to the uterine cervix for delivering a highly focused
beam of HIFU energy, depicted by dotted line, to a treatment site
within the uterus. In this illustration, the treatment site is a
uterine fibroid 4. By mating against the cervix, the HIFU therapy
transducer 2 is able to direct ultrasound emissions that are
limited to the uterine tissue, thereby enhancing the therapeutic,
and possibly diagnostic, effects of the ultrasound energy by
emitting the energy through a constant uterine tissue medium.
[0035] An additional coupling device can be used between the
transducer 2 and the cervix to optimize the ultrasound
transmission. The coupling may further include a cooling component.
Known in the art are various pillows filled with fluid that can
provide a cooled coupling between a HIFU transducer and a mass of
tissue. The probe 1, shown in FIG. 1, further includes a coupling 5
to an external source that may deliver a circulation of cooling
fluid, as well as energy to the probe 1 for operating the
components of the probe. The cooling fluid is used to lower the
temperature of the HIFU transducer as well as the tissue
surrounding the transducer, including but not limited to the
cervix, to decrease the risk of collateral thermal damage from the
focused HIFU beam. The coupling of the transducer 2 to the cervix
further enables the clinician to manipulate the position of the
cervix and uterus to optimize the HIFU treatment.
[0036] As will be discussed with respect to the remaining figures,
implementations of the invention are configured with a HIFU therapy
transducer having a compact state for insertion into the vaginal
cavity, after which the HIFU therapy transducer is deployed to a
larger state in which the transducer can deliver HIFU therapy to
target tissue in the body.
[0037] If desired, the probe 1 may further include an imaging
component that is operable to visualize the various pelvic organs
and pathologies. The imaging component may be designed to produce
two-dimensional or three-dimensional visual images of the tissue of
interest and/or blood flow of the tissue, as well as provide a
temperature quantification of the tissue in view. Further, while
the imaging system may be designed to use ultrasound energy,
imaging technologies are not limited to such an energy
modality.
[0038] As depicted, the therapeutic component of the HIFU
transducer may be constructed with various configurations to
achieve optimal focal length and aperture sizes and shapes to
achieve an optimal energy delivery for therapeutic purposes.
Implementations of the invention can be constructed, as described
herein, to provide optimal energy delivery to intended targets,
such as fibroid tumors in the uterus, while also addressing the
issue of limiting any collateral damage to adjacent tissue.
Furthermore, by managing the harmonics of transducer excitation, as
well as the phase and direction of energy emission, the shape and
location of the focal point of the HIFU transmission can be
adjusted.
[0039] Elements for generating HIFU energy are well known in the
art. A HIFU transducer may be configured with HIFU-generating
element arranged in an annular array, for example, which may allows
focal range control. Alternatively, the HIFU generating elements
may be arranged in a linear array, which may allows both focal
range and steering control. In yet other implementations, the
elements could be arranged in a two-dimensional array, which may
allows focal range and steering control in three dimensions. The
latter arrangement is preferably used in concert with a
two-dimensional imaging array that allows for three-dimensional
ultrasound visualization. Where multiple elements are used, the
elements may be phased with varying phase to allow proper focusing
of the HIFU transducer on various targets in the body.
Alternatively, HIFU emission from the multiple elements may be
coordinated to produce a beam as if coming from a single
element.
[0040] An apparatus for delivering HIFU energy constructed in
accordance with an implementation of the present invention, as
shown in FIG. 1, is shown in greater detail in FIG. 2. The
apparatus includes an elongate probe 10 having a proximal end 12
and a distal end 14. The proximal end 12 of the probe 10 preferably
has a section adapted for positioning the distal end 14 at a
desired location within a body cavity when the probe 10 is inserted
through an orifice into the patient's body. In this implementation,
the distal end 14 of the probe 10 has a HIFU therapy transducer 16
coupled thereto. The HIFU therapy transducer 16 comprises a
plurality of leaves 18. Each leaf 18, as shown, has a proximal end
20 and a distal end 22, as well as a deployment mechanism that will
be discussed in greater detail below. The proximal end 20 of each
leaf 18 is coupled to the distal end 14 of the probe 10.
[0041] Each leaf 18 has a front surface 24 adapted to direct HIFU
energy to a treatment site in the patient's body when the HIFU
therapy transducer 16 is deployed. In the implementation shown in
FIG. 2, the front surface 24 of at least one of the leaves includes
an active element 26 disposed thereon. The active element 26 is
operable to generate HIFU energy that is directed by the transducer
16 to the treatment site, such as the fibroid shown in FIG. 1.
HIFU-generating elements, as well as the signals and systems
required for operating the active elements to generate HIFU energy,
are well known in the art and need not be discussed in detail
herein. For example, HIFU elements using piezoelectric technologies
are known in the art and may be used in the implementations
discussed herein.
[0042] Depending on the materials used to construct the leaves 18
and the dimension of the leaves 18 in the HIFU therapy transducer
16, the leaves 18 may each be independently coupled to the probe
10, separate from one another. For stability of the transducer 16,
the leaves 18 may also be interconnected to each other if desired.
In FIG. 2, the leaves 18 are constructed to collapse to a smaller
state by sliding over the top of one another, thus reducing the
dimension of the HIFU therapy transducer from a deployed state, as
shown in FIG. 2, to a more compact state that facilitates insertion
of the probe 10 into a body cavity.
[0043] Each of the leaves 18 has a deployment mechanism that is
used to deploy the HIFU therapy transducer 16 to a state as shown
in FIG. 2 after the probe 10 is inserted into the patient. When
activated, the deployment mechanism is configured to deploy the
leaves 18 by directing the distal end 22 of the leaves 18 in a
radially outward direction. The leaves, thus deployed, collectively
provide a bowl-shaped HIFU therapy transducer 16 having an outer
edge 28 with a diameter that is larger than the diameter of the
probe 10. The HIFU therapy transducer 16, when deployed, has an
aperture of a size sufficient to direct a highly focused beam of
HIFU energy to a treatment site in a patient. When the deployment
mechanism is not activated, the collapsed leaves 18 occupy a space
having a diameter smaller than the diameter of the outer edge 28 of
the transducer 16 when the leaves 18 are deployed.
[0044] In the implementation shown in FIG. 2, as well as certain
other implementations disclosed herein, the probe 10 includes a
sleeve 30 disposed around a shaft 32. The sleeve 30 has a proximal
end 34, a distal end 36, and a longitudinal axis extending
therebetween. The shaft 32 is configured to slide within the sleeve
30 from a retracted position to an extended position along the
longitudinal axis of the probe 10.
[0045] To assist the sliding of the shaft from the retracted to the
extended position, an actuator, such as a button 38, may be
provided. In FIG. 2, the button 38 is connected to the shaft 32 and
slides within a groove 40 in the sleeve 30. A clinician operating
the probe may grasp the button 38 and slide it within the groove 40
to the position shown in FIG. 2 to place the shaft in the extended
position.
[0046] When the button 38 is slid through the groove 40 toward the
proximal end 34 of the probe, the shaft 32 is pulled within the
sleeve 30. As the shaft 32 is sliding inward, the leaves 18 contact
the distal end 36 of the sleeve 30 and inwardly contract to be
pulled within the sleeve 30. In the implementation shown, a portion
of each leaf 18 is designed to slide over in front of an adjacent
leaf 18 as the shaft 32 is pulled within the sleeve 30 and the
leaves 18 contract.
[0047] FIG. 2 additionally illustrates a hinge 42 at the distal end
14 of the probe 10. In this implementation, the HIFU therapy
transducer 16 is coupled to the distal end 14 of the probe 10 via
the hinge 42. The hinge 42 has an axis about which the transducer
16 can rotate to aim the HIFU energy toward the treatment site in
the patient's body, e.g., as depicted in FIG. 1.
[0048] FIGS. 3A-3C illustrate an implementation of an elongate
probe 50 having a HIFU therapy transducer 52 comprised of
retractable leaves 54, similar to the probe 10 shown in FIGS. 1 and
2. The probe 50 includes a sleeve 56 disposed around a shaft 70
(FIG. 4) inside the sleeve. The sleeve 56 has a proximal end 58, a
distal end 60, and a longitudinal axis 62 extending therebetween.
The shaft is configured to slide inside the sleeve 56 from a
retracted position, as shown in FIG. 3A, to an extended position,
as shown in FIG. 3C, along the longitudinal axis 62. FIG. 3B
illustrates the shaft at an intermediate stage between the
retracted and extended positions.
[0049] As with the implementation shown in FIGS. 1 and 2, each leaf
54 has a front surface 64 adapted to direct HIFU energy to a
treatment site when the probe 50 is inserted into a patient's body.
An active element 66 disposed on the front surface 64 is operable
to generate the HIFU energy that is directed to the treatment site.
Although the implementation in FIGS. 3A-3C depicts multiple leaves
54 having a front surface 64 with an active element 66, not all of
the leaves 54 are required to have an active element. Indeed, in at
least some implementations, the front surface 64 may be designed
without any active elements for generating HIFU energy. Instead,
the front surface 64 of at least one of the leaves 54 is configured
to reflect HIFU energy toward the treatment site, wherein the HIFU
energy is received from a source that is remote from the leaf. For
example, a HIFU energy source may be coupled to the probe at a
location central to the HIFU therapy transducer 52 but away from
the leaves 54. Alternatively, a HIFU energy source may be located
separate from the probe 50. In either case, the front surface 64 of
at least one of the leaves 54 is provided with a mirror-like
material that reflects HIFU energy incident upon the surface 64.
Materials with properties known for reflecting incident energy are
readily available and recognized by persons having ordinary skill.
The geometry of the leaves 54, when in a deployed state, is
configured to direct the HIFU energy to a focal point at the
intended treatment site in the patient.
[0050] FIG. 4 illustrates a side section view of the probe 50 shown
in FIG. 3B. In FIG. 4, the sleeve 56 is shown disposed around the
shaft 70. Each of the leaves 54 has a proximal end 72 and a distal
end 74. The proximal end 72 of each leaf 54 is coupled to a distal
end 76 of the shaft 70, e.g., through a pin, adhesive, welding, or
the like. Where the leaf 54 includes an active HIFU-generating
element, the coupling further includes a means for conveying energy
from the probe 50 to the active element, such as a wire.
[0051] Each leaf 54 further includes a deployment mechanism that,
when activated, deploys the leaves 54 by directing the distal end
72 of the leaves in a radially outward direction. In the
implementation shown in FIGS. 3A-3C and in FIG. 4, the deployment
mechanism of each leaf includes a pin 78 that is coupled to the
distal end 60 of the sleeve 56. The pin 78 is configured to slide
within a groove 80 (FIGS. 3B and 3C) defined in the leaves 54.
[0052] Activation of the deployment mechanism in this
implementation comprises sliding the shaft 70 within the sleeve 56
toward the extended position shown in FIG. 3C. As the shaft 70
slides upward through the sleeve 56, each leaf 54 is pushed outward
from the distal end 60 of the sleeve 56. As each leaf is pushed
outward, the pin 78 for each respective leaf 54 slides within the
groove 80 to direct the distal end 74 of the leaf radially outward
to a desired position in which the leaves collectively provide a
bowl-shaped HIFU transducer 52, as shown in FIG. 3C.
[0053] In the illustrated implementation, the grooves 80 are
defined at an angle relative to the longitudinal axis 62 such that
the leaves 54 are directed sideways, as well as outward, when the
shaft 70 is slid to the extended position. Similarly, when the
shaft 70 is drawn to the retracted position shown in FIG. 3A, the
pin 78 for each leaf 54 slides within the groove 80 to guide the
leaf laterally and radially inward as the leaves are pulled into
the sleeve 56. As depicted in FIG. 3B, at least a portion of a leaf
54 in the plurality of leaves is configured to overlap at least a
portion of another leaf 54 when the leaves are retracted and held
within the sleeve 56. To assist with retracting or extending the
shaft 70, an actuator, such as a button 82, may be attached to the
shaft 70, as shown in FIGS. 3A-3C. As with the implementation shown
in FIGS. 1 and 2, the button 82 may slide within a groove 84
defined in the sleeve 56. A force exerted on the button 82 in a
direction toward or away from the distal end 60 of the sleeve 56 is
translated to the shaft 70 for moving the shaft 70 within the
sleeve.
[0054] If desired, the pin 78 may include a detent that is
configured to secure the pin within the groove 80 in each
respective leaf. Furthermore, if desired, the probe 50 may be
configured such that the distal end 76 of the shaft 70 extends
beyond the distal end 60 of the sleeve 56 when the shaft is in the
extended position, thus exposing the distal end 76 of the shaft 70
outside the sleeve 56. This latter feature may be advantageous when
the probe 50 is configured with an imaging component 86 at the
distal end 76 of the shaft 70. Coupling an imaging component 86 to
the distal end of the shaft, or otherwise to the distal end of the
probe, may assist in the process of delivering HIFU therapy to the
patient.
[0055] The imaging component 86 is preferably adapted to produce an
image of a portion of the patient's body that includes the
treatment site receiving the HIFU energy. Conventional imaging
technologies may be used. The image may help guide the delivery of
HIFU energy to the treatment site. In one aspect, the imaging
component may be configured to use reflected ultrasound energy to
produce the image of the portion of the patient's body. Diagnostic
ultrasound uses ultrasound energy at a much lower power density so
as not to damage tissue. Reflected ultrasound energy can measure
tissue forms and densities at various depths in the patient's
body.
[0056] Alternatively, the imaging component 86 may be configured to
use reflected light to produce a visual image of a portion of the
patient's body. Light-based imaging technologies may include
elements such as fiber optic transmission and reception of light,
lenses (as needed), and/or electronic charge-coupled devices (CCDs)
that can receive and measure reflected light to produce an
image.
[0057] Where reflected ultrasound energy is used to produce an
image, the emission and reception of diagnostic ultrasound energy
should be synchronized with the transmission of HIFU energy so as
not to obscure the image obtained by the imaging component 86.
Technologies for synchronizing imaging and HIFU pulses are
available in the art. See, e.g., U.S. patent application
Publication No. 2006/0264748, titled "Interference-Free Ultrasound
Imaging During HIFU Therapy, Using Software Tools," by Shahram
Vaezy et al., the disclosure of which is incorporated by reference
herein.
[0058] Additionally, imaging technologies may be used to provide
real-time two-dimensional or three-dimensional viewing of the
target site, as well as blood flow color imaging (Doppler) and
temperature change quantifications of the target tissue, using
ultrasound back scatter information obtained from either the HIFU
transducer or the imaging component.
[0059] FIGS. 5A and 5B illustrate an implementation of a probe 100
with features similar to those shown and described with respect to
FIGS. 1-4, including a plurality of leaves 102 that can be deployed
to collectively provide a bowl-shaped HIFU transducer 104. As with
the previously described implementations, the probe 100 further
includes a sleeve 106 disposed around a shaft within the sleeve. An
actuator, such as the button 108, is connected to the shaft to
assist in sliding the shaft from a retracted position, as shown in
FIG. 5A, to an extended position, as shown in FIG. 5B.
[0060] In contrast to the previously described implementation, the
leaves 102 are coupled to the sleeve 106. More specifically, each
leaf 102 has a proximal end 110 and a distal end 112. The proximal
end 110 of each leaf is coupled to the distal end 114 of the sleeve
106. Furthermore, the proximal end 116 of the sleeve 104 may have a
section adapted for positioning the distal end 114 at a desired
location within a patient's body when the probe 100 is inserted
into the patient.
[0061] As further depicted in dotted line in FIG. 5A, a plurality
of spines 118 may be coupled to the distal end 120 of the shaft
within the sleeve 106. When the shaft is in the retracted position,
as shown in FIG. 5A, the spines 118 are held within the sleeve 106.
The leaves 102 are constructed such that they can overlap one
another in a collapsed configuration as shown, where the leaves 102
are capable of being grouped together to occupy a smaller space.
For example, as shown in FIG. 5A, the group of leaves 102 may
occupy a space having a diameter that is equal to or smaller than
the diameter of the sleeve 106. Having the leaves in a collapsed
state facilitates insertion of the probe 100 into a patient's body.
After the probe 100 is inserted into the intended cavity of a
patient's body, the leaves 102 may be deployed using a deployment
mechanism, namely, the spines 118, to direct the distal end 112 of
each leaf in a radially outward direction to a desired position to
provide the bowl-shaped HIFU transducer 104.
[0062] Thus, in operation, activation of the deployment mechanism
for FIGS. 5A and 5B comprises sliding the shaft within the sleeve
106 toward the extended position, as depicted in FIG. 5B. As the
shaft is slid within the sleeve, the spines 118 emerge from the
sleeve 106 and slide within grooves 122 defined in each of the
leaves 102. As the spines 118 progressively enter the grooves 122,
the spines 118 direct the distal end 112 of each of the leaves 102
in a radially outward direction. The spines 118 also provide
support to the leaves 102 when the plurality of leaves are
deployed. Pulling the shaft into the sleeve 106 toward the
retracted position withdraws the spines 118 from the grooves 122,
which allows the leaves 102 to collapse to the state shown in FIG.
5A.
[0063] The spines 118 may be constructed of a suitable material
capable of providing support to the leaves 102 when the shaft is
extended and the leaves are deployed. The spines 118 may be
configured to exert an outwardly directed bias force on the leaves
102 when the shaft is extended and the spines 118 fill the grooves
122. The spines 118 are constructed to hold the leaves 104 in the
deployed state, as shown in FIG. 5B. If desired, one or more stops
may be defined in the distal end 114 of the sleeve 106 to engage
the leaves 102 once the leaves have reached the deployed position.
The outwardly-directed bias force of the spines 118 may derive from
a natural characteristic of the materials used to construct the
spines, such as a spine formed of a material having an
outwardly-directed curve in a resting state outside the sleeve 106,
which is flexible to bend to a straight non-resting state inside
the sleeve 106. Alternatively, a mechanism, such as a spring, may
be configured with the spines 118 to bear against the spines 118
and direct the leaves in a radially outward direction when
deployed.
[0064] In another alternative implementation, a deployment
mechanism comprised of springs having a first end coupled to the
shaft and a second end disposed within the leaf, may be used. An
implementation using springs for deployment may be visualized using
the drawings in FIGS. 3A-3C, wherein the grooves 80 are filled with
the second end of a spring, as described, instead of being guided
by pins 78 in the sleeve 56. In this case, the second end of the
springs need not be disposed at an angle as the grooves 80 are
depicted. As the shaft within the sleeve 56 is slid upward to an
extended position, as shown in FIG. 3C, the second end of the
springs emerges from the sleeve 56 and exerts an outward bias to
direct the distal end of the leaves 54 in a radially outward
direction. Similarly, retracting the shaft within the sleeve 56
pulls the leaves 54 with the springs into the sleeve 56, wherein
the leaves and springs are held, as shown in FIG. 3A.
[0065] In yet another implementation, a portion of the leaves, such
as the leaves 102 shown in FIG. 5B, may be formed of an
energy-activated shape memory alloy. The deployment mechanism of
the leaves 102 in this implementation includes a coupling that
connects the shape memory alloy to an energy source. Activation of
the deployment mechanism comprises delivering energy from the
energy source to the shape memory alloy in each leaf that causes
the shape memory alloy to take a predefined shape in which the
distal end of the leaves 102 are directed radially outward to
provide a bowl-shaped HIFU transducer 104.
[0066] A typical shape memory alloy is made of nickel and titanium
and is known for its flexibility as well as shape changing
properties. The alloy dynamically changes its internal structure at
certain temperatures. Structures formed with a shape memory alloy,
such as the leaves 102, can be deformed at room temperature, and
when the shape member alloy is heated, the alloy causes the
structure to shift to a predefined shape. For example, shape memory
alloys may contract when heated and then be easily stretched out
again as they return to their original temperature. Energy-driven
heating and cooling of a shape memory alloy can be accomplished
quite quickly.
[0067] In the context of the present invention, a probe, such as
the probe 100 shown in FIG. 5B (without spines 118 shown in FIG.
5A), may include a plurality of leaves 102 having a proximal end
110 coupled to the probe. Some or all of each leaf 102 may be
formed of a shape memory alloy. As energy from an energy source
within the probe is delivered to the shape memory alloy of the
leaves, the leaves flex in a radially outward direction to provide
the HIFU therapy transducer 104, as shown. In an implementation
where spines 118 are used, the spines may be formed of a shape
memory alloy which, being activated by the application of energy to
the alloy, cause each of the spines 118 to flex in a radially
outward direction, thus placing the leaves 102 in a deployed state.
In such implementations, the spines 118 may or may not retract
within grooves 122, as shown in FIG. 5A. Where the spines 118 do
not retract, the leaves 102 are still capable of collapsing into a
group, as shown in FIG. 5A, when the shape memory alloy of the
spines 118 is not activated by the energy source.
[0068] Turning now to FIGS. 6A and 6B, another implementation
constructed in accordance with the present invention comprises an
elongate probe 130 having a proximal end 132, a distal end 134, and
a longitudinal axis 136 extending therebetween. As with other
implementations herein, the proximal end 132 of the probe 130 may
have a section adapted for positioning the distal end 134 of the
probe at a desired location within a patient's body when the probe
130 is inserted into the patient.
[0069] The distal end 134 of the probe 130 is fitted with a
flexible material 138 that couples a HIFU therapy transducer 140 to
the probe 130. The HIFU therapy transducer 140 has an aperture of a
size sufficient to direct therapeutic HIFU energy to a treatment
site in the patient. For reference purposes, the HIFU therapy
transducer 140 has a major axis 142 extending across its face.
[0070] In a resting state, as shown in FIG. 6B, the flexible
material 138 couples the transducer 140 to the probe 130 in a
therapy position wherein the major axis 142 of the transducer is
non-parallel to the longitudinal axis 136 of the probe. To
facilitate insertion of the probe 130 in a patient's body, e.g.,
through the vaginal introitus, the flexible material 138 is
configured to stretch and allow the transducer 140 to be drawn to
the side of the probe 130 to an insertion position as shown in FIG.
6A. In the insertion position, the major axis 142 of the transducer
140 is generally parallel to the longitudinal axis 136 of the probe
130. This allows the largest dimension of the transducer 140 to be
in the sagittal axis of the vaginal introitus. The flexible
material 138, thus stretched, exhibits a bias to return toward its
resting state as shown in FIG. 6B. After the probe 130 has been
inserted into the intended cavity of a patient's body, such as the
vaginal cavity, the transducer 140 is released from the insertion
position and allowed to return to the therapy position shown in
FIG. 6B.
[0071] If desired, an actuator may be coupled to the HIFU therapy
transducer 140 to draw the transducer 140 to the side of the probe
130 while the probe is either being inserted into the patient or
withdrawn from the patient. The actuator may also be manipulated to
deploy the transducer 140 to the therapy position shown in FIG. 6B.
Suitable actuators include, but are not limited to, a cable and/or
a latch that can pull, push, and/or hold the transducer in an
insertion position as shown in FIG. 6A or in a therapy position as
shown in FIG. 6B. In at least one implementation, manipulating the
actuator to deploy the transducer 140 may simply involve releasing
the transducer and allowing the flexible material 138 to place the
transducer in a therapy position. In another implementation, the
actuator may actively move the transducer 140 to the desired
therapy position.
[0072] As with other implementations previously described, the
distal end 134 of the probe 130 may include an imaging component
144 adapted for producing an image of a portion of the patient's
body when the probe 130 has been inserted in the patient.
Preferably, the image produced by the imaging component includes
the treatment site receiving the HIFU energy from the transducer
140 to help guide the delivery of the HIFU energy to the treatment
site. In one implementation, the imaging component may be
configured to use reflected ultrasound energy to produce the image
of the portion of the patient's body. In an alternative
implementation, the imaging component may be configured to use
reflected light to produce the image. In either case, the image
produced by the imaging component may further include a portion of
the HIFU therapy transducer 140 to assist in positioning the
transducer 140 within the patient's body and in monitoring the HIFU
therapy occurring at the treatment site.
[0073] In a suitable implementation, the flexible material 138 may
be comprised of a resilient, non-metal material, such as a medical
grade plastic, rubber, or silicon. In an alternative
implementation, the flexible material 138 may be comprised of a
shape memory alloy having a stretched state or resting state
dependent on energy activation of the alloy. The shape memory alloy
may be activated to assume a predefined shape based on energy
supplied to the alloy which typically heats the alloy and causes
the change in shape. Details regarding the structure and use of
shape memory alloys have been discussed earlier herein.
[0074] Also, as with earlier described implementations, an active
element 146 may be disposed on the HIFU therapy transducer 140,
wherein the active component is operable to generate the HIFU
energy that the transducer 140 directs to the treatment site.
Alternatively, the HIFU therapy transducer 140 may be configured
with a surface that reflects HIFU energy toward the treatment site.
The HIFU energy in this latter implementation may be received from
a source that is remote from the transducer 140. Materials, such as
a reflective Mylar, capable of reflecting ultrasound energy that is
incident thereon, are known in the art.
[0075] In yet another implementation of an apparatus constructed
according to the present invention, a probe 160, as shown in FIGS.
7A and 7B, may be used to treat pathologies in a patient's body. To
facilitate insertion of the probe 160 in the patient, the probe 160
is configured with a HIFU therapy transducer formed of one or more
inflatable bladders.
[0076] As with prior implementations, the elongate probe 160 has a
proximal end 164 and a distal end 166. The proximal end 164
preferably has a section adapted for positioning the distal end 166
of the probe at a desired location when the probe 160 is inserted
into a patient's body. The distal end 166 of the probe 160 is
fitted with a flexible material having one or more inflatable
bladders that, when inflated, provide the HIFU therapy transducer
162. The transducer 162 has an aperture of a size sufficient to
direct a focused beam of therapeutic HIFU energy to a treatment
site in a patient. The inflatable bladders may be constructed of an
expandable material, such as (but not limited to) rubber or
silicon.
[0077] The one or more inflatable bladders 168 extend radially
outward from the distal end 166 of the probe 160. The bladders 168
are not inflated until after the probe is inserted into the
intended cavity of the patient's body, such as through the vaginal
introitus into the vaginal cavity. After insertion, the bladders
168 are inflated to form and provide lateral support to the HIFU
therapy transducer 162 within the patient's body. When inflated,
the transducer 162 has an aperture that is larger than the diameter
of the probe 160. Appropriate conduits for delivering a pressurized
fluid, such as a liquid or gas, to the inflatable bladders 168 are
provided within the probe 160 and coupled to the bladders 168.
Likewise, conduits are provided to conduct the fluid away from the
bladders 168 when the bladders are deflated. If desired, the fluid
(liquid or gas) may be circulated to and from the bladders 168 and
cooled to help manage the temperature of the transducer 162 and/or
tissue adjacent to the transducer 162 when HIFU therapy is being
applied.
[0078] As further depicted in FIG. 7B, the flexible material
forming the HIFU therapy transducer 162 has a front surface 170
adapted to direct HIFU energy to the treatment site in the patient
when the probe 160 is inserted and the bladders 168 are
inflated.
[0079] In the implementation illustrated in FIGS. 7A and 7B, the
bladders 168 comprise one or more inflatable channels that extend
radially outward from the distal end 166 of the probe 160. The
front face 170 of the flexible material extends between the
inflatable channels 168.
[0080] If desired, the inflatable channels 168 may terminate in an
inflatable ring 172 that forms an outer edge 174 of the HIFU
therapy transducer 162. The ring 170, when inflated, provides
further support to the HIFU therapy transducer 162 and maintains
the aperture of the transducer for delivery of HIFU therapy to the
patient. When inflated, the diameter of the ring 172, measured as a
cross-section of the ring, is larger than the diameter of the probe
160, measured at the distal end 166 of the probe.
[0081] In FIG. 7B, the front surface 170 of the flexible material
is shown with one or more active elements 176 that are operable to
generate HIFU energy that is directed by the transducer 162 to the
treatment site in the patient. As noted earlier, HIFU generating
elements are known in the art. Conduits for providing energy to the
active element 176 are provided within the probe 160.
Alternatively, the front surface 170 may be configured with a
material that reflects HIFU energy toward the treatment site. As
with other implementations described herein, the HIFU energy may be
received from a source that is remote from the flexible
material.
[0082] Additionally, as with other implementations described
herein, the distal end 166 of the probe 160 may further include an
imaging component 176 adapted for producing an image of a portion
of the patient's body that includes the treatment site. Imaging of
the patient in this manner may help guide the delivery of HIFU
energy to the treatment site. The imaging component 176 may be
configured to use reflected ultrasound energy or reflected light to
produce the image, as described earlier herein. The image produced
by the imaging component 176 may further include a portion of the
HIFU therapy transducer 162 to assist in positioning the transducer
within the patient's body and in monitoring HIFU therapy being
delivered at the treatment site.
[0083] FIG. 8 illustrates an implementation of a probe 180 that is
likewise fitted with a flexible material having an inflatable
bladder that, when inflated, provides a HIFU therapy transducer
182. The transducer 182 may include one or more active elements
184, as shown, or provide a reflective mirror surface that reflects
HIFU energy toward the treatment site. In contrast to the
implementation with inflatable channels 168 shown in FIGS. 7A and
7B, FIG. 8 depicts an implementation with a single inflatable
bladder 186 that, when inflated, is capable of providing HIFU
therapy to a patient. To facilitate insertion of the probe 180 in
the patient's body, the bladder 186 is not inflated until after the
probe is inserted in the intended cavity of the patient's body. The
bladder 186, when inflated, forms and provides lateral support to
the HIFU therapy transducer 182.
[0084] Turning now to FIGS. 9A and 9B, an apparatus for delivering
HIFU energy to a treatment site internal to a patient's body is
shown in accordance with another implementation of the invention.
The apparatus includes an elongate probe 200 having a proximal end
202, a distal end 204, and a longitudinal axis 206 extending
therebetween. The proximal end 202 of the probe 200 preferably has
a section adapted for positioning the distal end 204 of the probe
at a desired location within the patient's body.
[0085] Further depicted in FIGS. 9A and 9B is a support structure
208 having an imaging component 210 and a HIFU therapy transducer
212 disposed thereon. A hinge 216 connects the support structure
208 to the distal end 204 of the probe 200.
[0086] The imaging component 210 is adapted for producing an image
of a portion of the patient's body that includes the treatment
site, while the HIFU therapy transducer is adapted for delivering
HIFU energy to the treatment site. The HIFU therapy transducer has
an aperture of a size sufficient to direct therapeutic HIFU energy
to the treatment site and is disposed on the support structure 208
in defined relation to the imaging component 210. In the particular
implementation shown, the HIFU therapy transducer 212 is
bowl-shaped, and the imaging component 210 is disposed within the
interior of the therapy transducer 212.
[0087] To facilitate insertion of the probe 200 in the patient's
body, e.g., through the vertical axis of the vaginal introitus, the
support structure 208 is capable of rotating about the hinge 214 to
an insertion position generally parallel to the longitudinal axis
206 of the probe 200, as shown in FIG. 9B. In at least one
implementation, the dimension of the therapy transducer 212 in its
insertion position and measured perpendicular to the longitudinal
axis 206 of the probe is smaller than the dimension of the
transducer 212 measured parallel to the longitudinal axis 206. The
hinge 214 provides an articulation that enables the imaging and
therapy transducers 210, 212 as a unit to be positioned relative to
the treatment site in the patient's body. In this implementation,
the alignment of the imaging and HIFU therapy is maintained, thus
maintaining the focal range of the HIFU therapy field in the same
region on the image plane. Advantageously, this region can
determined and calibrated at the factory. Thereafter, as a result,
software control of HIFU transducer will be simpler.
[0088] After insertion of the distal end 204 of the probe 200 in a
patient's body, the support structure 208 is capable of rotating
about the hinge 214 to a position non-parallel to the longitudinal
axis 206 of the probe 200, as may be desired to effectively aim the
HIFU energy from the therapy transducer 212 to the treatment site
in the body. By rotation, the HIFU therapy transducer 212 can also
be placed in a better position for coupling to a bodily structure,
such as the uterine cervix of a female patient.
[0089] Lastly, FIGS. 10A and 10B depict an elongate probe 220
having features similar to those shown in the probe 200 of FIGS. 9A
and 9B. The probe 220 has a proximal end 222, a distal end 224, and
a longitudinal axis 226 extending therebetween. A support structure
228 bearing an imaging component 230 and a HIFU therapy transducer
232 is rotatable about a hinge 234 connected to the distal end 224
of the probe 220.
[0090] In contrast to the probe 200 shown in FIGS. 9A and 9B, the
imaging component 230 shown in FIGS. 10A and 10B is disposed on the
support structure 228 to the exterior of the HIFU therapy
transducer 232. Having the imaging transducer to the exterior of
the therapy transducer in some circumstances may provide a more
advantageous angle for imaging the treatment site and the effects
of the HIFU therapy being delivered thereto.
[0091] In a suitable implementation, the imaging component 230 as
well as the imaging component 210 may be configured to use
reflected ultrasound energy to produce an image of a portion of the
patient's body. In other suitable implementations, the imaging
component 230 and/or the imaging component 210 may be configured to
use reflected light to produce a visual image. Where reflected
ultrasound energy is used to produce the image, an implementation
of the invention may use the same transducer, such as the
transducers 212 and/or 232, to perform both the imaging and
delivery of HIFU therapy. Appropriate synchronization of the
imaging and HIFU pulses will be desired. Nevertheless, in such
cases, an imaging component 210, 230 separate from the therapy
transducer 212, 232 is not necessary. If a portion of the HIFU
therapy transducer is shown in the image, the image may further
assist in positioning the HIFU therapy transducer within the
patient's body and in monitoring the delivery of HIFU therapy at
the treatment site.
[0092] An overall control system for the above-described probes can
be implemented using computer hardware and/or software. A control
system may provide tools for clinicians to program a treatment
strategy for a specific region of interest in the body. The tools
may include setting various focal lengths to treat a
two-dimensional or three-dimensional region in the tissue, setting
an appropriate power level for excitation of the HIFU transducer to
obtain a desired intensity at the focus (either for a single
element HIFU or a multi-element HIFU transducer) based on expected
attenuation of the tissue between the HIFU transducer and the
focus, setting a duration of the HIFU application, setting a
threshold for power above which the system should shut down for
safety purposes, and setting a duty cycle of the HIFU exposure with
respect to ultrasound image acquisition. An interface may also
provide tools for the clinician to override the computer plan and
design a treatment plan based on their discretion. The interface
may continually update the clinician of the stage of the treatment
and the next steps to be taken, as well as advise whether the plan
should proceed or be altered. Finally, the interface may
continually interrogate the acoustic path (pre- and post-focal) for
bone and gas interfaces that could potentially result in excessive
energy deposition, leading to potential undesired tissue
damage.
[0093] For purposes of example only, various implementations have
been described above for treating pathologies of the female
reproductive system where necrosis of a region of tissue has a
therapeutic effect. By way of example, and not by limitation, these
implementations can be used to treat uterine fibroids, adenomyoma
of the uterus, adenomyosis of the uterus, endometrial polyps,
endometrial ablation to achieve reduction or elimination of
menstrual flow, endometrial hyperplasia, cornual pregnancy, benign
ovarian cysts, pelvic endometriosis, ectopic pregnancy, and
malignant lesions of the pelvic organs, whether primary or
metastatic.
[0094] As may be appreciated from the various implementations
described herein, there are a variety of features and advantages
obtained when constructing a probe in accordance with the present
invention. Furthermore, although the invention has been described
in connection with certain depicted implementations, those of
ordinary skill will recognize that one or more features of a
particular implementation described herein may be used in another
implementation for similar advantage. Accordingly, it is not
intended that the scope of the invention in any way be limited by
the precise forms described above, but instead be determined by
reference to the claims that follow and equivalents thereto.
* * * * *