U.S. patent application number 13/093030 was filed with the patent office on 2011-08-18 for laparoscopic hifu probe.
This patent application is currently assigned to FOCUS SURGERY, INC.. Invention is credited to Roy F. Carlson, Wo-Hsing Chen, Russell J. Fedewa, Artur P. Katny, Paul W. Mikus, Narendra T. Sanghvi, Ralf Seip, Dan Voic.
Application Number | 20110201976 13/093030 |
Document ID | / |
Family ID | 44370145 |
Filed Date | 2011-08-18 |
United States Patent
Application |
20110201976 |
Kind Code |
A1 |
Sanghvi; Narendra T. ; et
al. |
August 18, 2011 |
LAPAROSCOPIC HIFU PROBE
Abstract
A high-intensity focused ultrasound ablation of tissue using
minimally invasive medical procedures is provided.
Inventors: |
Sanghvi; Narendra T.;
(Indianapolis, IN) ; Seip; Ralf; (Indianapolis,
IN) ; Fedewa; Russell J.; (Indianapolis, IN) ;
Carlson; Roy F.; (New Palestine, IN) ; Chen;
Wo-Hsing; (Fishers, IN) ; Katny; Artur P.;
(Ingalls, IN) ; Mikus; Paul W.; (Coto de Caza,
CA) ; Voic; Dan; (Cedar Grove, NJ) |
Assignee: |
FOCUS SURGERY, INC.
Indianapolis
IN
|
Family ID: |
44370145 |
Appl. No.: |
13/093030 |
Filed: |
April 25, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11968714 |
Jan 3, 2008 |
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13093030 |
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11445004 |
Jun 1, 2006 |
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11968714 |
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60686499 |
Jun 1, 2005 |
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Current U.S.
Class: |
601/2 |
Current CPC
Class: |
A61N 7/022 20130101;
A61N 2007/0052 20130101; A61B 2090/378 20160201; A61N 2007/0065
20130101 |
Class at
Publication: |
601/2 |
International
Class: |
A61F 7/00 20060101
A61F007/00 |
Claims
1-9. (canceled)
10. A method of providing high intensity focused ultrasound therapy
to a treatment zone comprising: positioning a transducer in
relation to a target tissue region of a patient, wherein the
transducer is configured to provide HIFU therapy; energizing the
transducer to provide HIFU therapy at a focal point within a
treatment zone; operating a computer to calculate a path of
movement of the transducer; further operating the computer to move
the transducer along the path; and energizing the transducer to
provide HIFU therapy into the treatment zone while the transducer
is moving along the path, thereby treating contiguous portions of
tissue with HIFU.
11. The method of claim 10, further comprising inputting into the
computer information identifying the location of the target tissue
region inside the patient, the computer utilizing the information
to calculate the path.
12. The method of claim 11, further comprising the steps of:
operating the transducer in an imaging mode; acquiring an image of
the target tissue region of the patient; at least in part from the
results of the image, determining that the tissue in the treatment
zone should be treated; and fine tuning the position of the
transducer relative to the target tissue region by software
controls.
13. The method of claim 12, wherein the image is provided on a
display.
14. The method of claim 11, wherein the inputting of the
information identifying the location of the target tissue region
includes positioning and resizing a treatment zone to cover the
target tissue region.
15. The method of claim 10, wherein the path of movement of the
transducer covers the entire treatment zone.
16. The method of claim 15, wherein the path of movement of the
transducer has a trajectory which has equal trace spacing and is
substantially uniform throughout the treatment zone.
17. The method of claim 15, wherein the transducer is continuously
moving at a constant speed and continuously applying HIFU to the
treatment zone.
18. The method of claim 10, wherein the computer provides a user
with feedback during the treatment and the feedback is provided on
a display.
19. The method of claim 10, wherein the computer changes the path
of the transducer at an angle of about 90 degrees if the path hits
a boundary edge of the treatment zone defined by a user.
20. The method of claim 10, wherein the transducer ceases to apply
HIFU to the treatment zone upon the occurrence of two consecutive
out-of-bounds readings prior to completion of the transducer's
movement along the path prior to the completion of a move.
21. The method of claim 10, wherein the computer implements
"intelligent" checking to reduce treatment interruptions due to
single errors.
22. The method of claim 10, wherein the computer performs a check
to verify that the distance to a destination of the transducer is
decreasing.
23. The method of claim 10, wherein the computer performs safety
checks and recovery algorithms.
24. The method of claim 12, further comprising the step of
providing to a user an image update of the target tissue region
during treatment.
25. An apparatus for providing high intensity focused ultrasound
therapy to a treatment zone comprising: a transducer which is
positionable relative to the target tissue region of a patient,
wherein the transducer is configured to provide HIFU therapy; a
servomechanism connected to the transducer configured to move the
transducer along a path in a treatment zone; a computer connected
to the servomechanism and configured to determine the path and
controlling the servomechanism to move the transducer along the
path, the computer configured to have the transducer continuously
apply HIFU therapy into the treatment zone while the transducer is
moving along at least a portion of the path.
26. The apparatus of claim 15, further comprising at least one
input peripheral connected to the computer for enabling a user to
input into the computer information identifying the location of the
target tissue region inside the patient, the computer utilizing the
information to calculate the path.
27. The apparatus of claim 16, wherein the input peripheral
includes a touch-sensitive display screen.
28. The apparatus of claim 17, further comprising a transducer
having an imaging mode, the computer configured to operate the
transducer in the imaging mode and capable of acquiring an image of
the target tissue region of the patient, and a display for
displaying the images.
Description
[0001] This application is a divisional of U.S. patent application
Ser. No. 11/445,004, filed Jun. 1, 2006, titled "LAPAROSCOPIC HIFU
PROBE", Docket FOC-P004-01 which claims the benefit of U.S.
Provisional Application Ser. No. 60/686,499, filed on Jun. 1, 2005,
the disclosures of which are expressly incorporated by reference
herein.
BACKGROUND AND SUMMARY OF THE INVENTION
[0002] The present invention relates to instruments to conduct
minimally invasive medical procedures with the aid of laparoscopic
techniques, and to such procedures themselves. More particularly,
the present invention relates to high-intensity focused ultrasound
ablation of tissue using minimally invasive medical procedures.
[0003] Several minimally invasive and non-invasive techniques for
the treatment of living tissues and organs with ultrasound,
including high-intensity, focused ultrasound, sometimes referred to
hereinafter as HIFU, are known. There are, for example, the
techniques and apparatus described in U.S. Pat. Nos. 4,084,582;
4,207,901; 4,223,560; 4,227,417; 4,248,090; 4,257,271; 4,317,370;
4,325,381; 4,586,512; 4,620,546; 4,658,828; 4,664,121; 4,858,613;
4,951,653; 4,955,365; 5,036,855; 5,054,470; 5,080,102; 5,117,832;
5,149,319; 5,215,680; 5,219,401; 5,247,935; 5,295,484; 5,316,000;
5,391,197; 5,409,006; 5,443,069; 5,470,350; 5,492,126; 5,573,497;
5,601,526; 5,620,479; 5,630,837; 5,643,179; 5,676,692; 5,840,031.
The disclosures of these references are hereby incorporated herein
by reference.
[0004] HIFU Systems for the treatment of diseased tissue are known.
An exemplary HIFU system is the Sonablate.RTM. 500 HIFU system
available from Focus Surgery, Inc. located at 3940 Pendleton Way,
Indianapolis, Ind. 46226. The Sonablate.RTM. 500 HIFU system uses a
dual-element, confocal ultrasound transducer which is moved by
mechanical methods, such as motors, under the control of a
controller. Typically one element of the transducer is used for
imaging and the other element of the transducer is used for
providing HIFU Therapy.
[0005] Further details of suitable HIFU systems may be found in
U.S. Pat. No. 5,762,066; U.S. Abandoned patent application Ser. No.
07/840,502 filed Feb. 21, 1992, Australian Patent No. 5,732,801;
Canadian Patent No. 1,332,441; Canadian Patent No. 2,250,081; and
U.S. Pat. No. 6,685,640, the disclosures of which are expressly
incorporated by reference herein.
[0006] As used herein the term "HIFU Therapy" is defined as the
provision of high intensity focused ultrasound to a portion of
tissue. It should be understood that the transducer may have
multiple foci and that HIFU Therapy is not limited to a single
focus transducer, a single transducer type, or a single ultrasound
frequency. As used herein the term "HIFU Treatment" is defined as
the collection of one or more HIFU Therapies. A HIFU Treatment may
be all of the HIFU Therapies administered or to be administered, or
it may be a subset of the HIFU Therapies administered or to be
administered. As used herein the term "HIFU System" is defined as a
system that is at least capable of providing a HIFU Therapy.
[0007] The laparoscopic probe of an illustrated embodiment of the
present invention is targeted for minimally invasive laparoscopic
tissue treatments of the kidney and liver. The probe is light
weight, easy to use, and adaptable to the current Sonablate.RTM.
500 HIFU system. The laparoscopic probe, with the Sonablate.RTM.
500 system, illustratively provides laparoscopic ultrasound
imaging, treatment planning, treatment and monitoring in a single
probe. The probe fits through a trocar (illustratively an 18
millimeter diameter trocar). A removable, sterile, and disposable
probe tip includes a coupling bolus which covers the tip of the
probe. The bolus is very thin and illustratively expands to about
two or three times its size when water is introduced. This provides
a water medium surrounding the probe which is needed for ultrasonic
imaging and treatment. Cooling the transducer that provides the
imaging and treatment is achieved through a sterile, distilled,
degassed passive recirculating water system. The entire probe is
ethylene oxide (EO) sterilizable, and the cooling system is
gamma-sterilizable.
[0008] The laparoscopic probe of the present invention provides an
alternative solution to invasive surgery. As a result, recovery
time is reduced and hospital visits are considerably shorter. In
addition the ablation provided by the laparoscopic probe permits
the surgeon to target tissue without stopping the blood supply to
the organ. For example, to perform a partial nephrectomy in a
conventional manner, the surgeon illustratively shuts off the
supply of blood to the kidney and has a limited amount of time to
excise the targeted tissue, seal the blood vessels and restart the
blood supply to the kidney. If the surgeon takes too long, damage
to the kidney and possible organ death may occur. Thus being able
to treat large and small volumes of tissue while permitting blood
flow to the organ is a significant contribution.
[0009] Additional features of the present invention will become
apparent to those skilled in the art upon consideration of the
following detailed description of illustrative embodiments
exemplifying the best mode of carrying out the invention as
presently perceived.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The detailed description of the drawings particularly refers
to the accompanying figures in which:
[0011] FIG. 1 is a perspective view of a portion of the
laparoscopic probe of the present invention including a controller,
a drive mechanism, and a movable transducer;
[0012] FIG. 2 is a perspective view of a removable probe tip
assembly of the present invention including an expandable bolus for
acoustically coupling the transducer to a targeted area and for
cooling the transducer during the procedure;
[0013] FIG. 3 is an exploded perspective view of the removable
probe tip assembly of FIG. 2;
[0014] FIG. 4 is a side elevational view of the removable probe tip
assembly of FIGS. 2 and 3;
[0015] FIGS. 5A and 5B illustrate sterile kit packages for use in a
fluid recirculation system of the present invention;
[0016] FIG. 6 illustrates a fluid recirculation system of the
present invention which controls expansion of the bolus of the
laparoscopic probe and also provides cooling to the transducer;
[0017] FIG. 7 is a sample screen shot for planning a HIFU
Treatment;
[0018] FIGS. 8A-8C illustrate a treatment path along which the
transducer is moved by the controller and drive mechanisms to treat
a treatment zone; and
[0019] FIG. 9 is a screen shot illustrating a sample procedure in
accordance with an illustrated embodiment of the present
invention.
DETAILED DESCRIPTION OF THE DRAWINGS
[0020] U.S. application Ser. No. 10/380,031, owned by Focus
Surgery, Inc. located in Indianapolis, Ind., discloses a HIFU
laparoscopic probe and minimally invasive treatment procedure. The
'031 application is expressly incorporated by reference herein.
[0021] In an illustrated minimally invasive procedure as described
in the '031 application, in a HIFU-based procedure for treatment of
a kidney, the patient is first prepared. Next, three incisions are
illustratively made on the abdomen below the diaphragm through
trocars. The trocars are left in place, as is customary, to permit
the sealing of the abdomen when instruments are passed through the
seals of the trocars into the abdomen for the conduct of the
procedure.
[0022] A laparoscope for providing visual observation of the
surgical field is passed through one of the trocars. The
laparoscope is conventionally coupled to a video camera and a light
source for illuminating the surgical field and returning images to
a surgical monitor. The laparoscope provides a pair of fiberoptic
ports, one an output port for light from source to the surgical
field, and one an input port for the returning image information to
video camera. A second of the trocars provides, among other things,
a passageway for the introduction into the abdomen of a relatively
inert gas, such as, for example, carbon dioxide, from a source in
order to permit the inflation of the abdomen below the diaphragm.
This increases the space inside the abdomen for maneuvering
surgical instruments including the laparoscope, and provides a
clearer view of the surgical field.
[0023] The third trocar provides access through the abdominal wall
and into the surgical field for a HIFU probe which is used to
ablate the surgical site of a diseased kidney, for example, for the
virtually bloodless ablation of (a) tumor(s) on the surface of,
and/or within, the kidney. Should the surgical procedure call for
it, additional trocars can, of course, be provided for passing into
the body additional HIFU probes 90 to be used in conjunction with
each other in an ablation procedure. If a tumor is difficult to
visualize, a catheter may be used to permit the introduction into
the surgical field of (an) ablation enhancing medium (media) and
other media at (an) appropriate time(s) during the procedure. The
same, or a different, medium (media) may also be introduced through
the catheter to improve the accuracy of the targeting of the
surgical site for ablation and provide feedback to the treating
physician of the progress of the treatment. For example, lesions
which are not on the surface of the tissue being treated are not
easily visible, or in many cases visible at all, in the
laparoscopically informed monitor.
[0024] In order to provide feedback to the treating physician of
the progress of treatment of a site not visible on the monitor, the
ultrasound probe includes an ultrasound visualization capability.
Additional mechanisms may be provided for essentially real-time
monitoring of the progress of the treatment. For example, it is
known in the ultrasound visualization and therapy arts that there
are numerous mechanisms available to promote visualization of the
progress of ultrasound treatment within an organ or tissue.
[0025] The probe is illustratively integrated into, or mounted to
be manipulated by, a drive mechanism, and controlled, for example,
by means of a joystick, keypad, touch screen, or any other
appropriate control mechanism such as controller. Any of such
mechanisms can incorporate feedback control, not only of a visual
nature, provided via a laparoscope, but also of the ultrasound
imaging type via probe.
[0026] As shown in FIG. 1, the probe 90 includes a segmented,
curved rectangular elliptical transducer 100 of the general type
described in, for example, WO 99/49788. The transducer 100 has a
central segment 102 which is used both for visualization and
therapy and outer segment(s) 104 which is (are) used for therapy,
in accordance with known principles. However, it will immediately
be appreciated that other single element or multi-segment
transducer configurations, such as ones providing variable focal
length, can be used to advantage in other embodiments of the
invention. Some of such variable focal length configurations, and
driving and receiving systems for them, are described in the prior
art incorporated herein by reference.
[0027] The structure of the laparoscopic probe 90 is composed of
two main components, the main body or frame, and the probe tip
assembly 111. The frame illustratively provides a drive mechanism
92 for moving the transducer 100 back and forth in the direction of
double headed arrow 106 in FIG. 1 (50 mm minimum movement), and
also to rotate the transducer 100 about its axis 107 as illustrated
by arrow 108. It is understood that other suitable drive
mechanism(s) 92 may be used to move the transducer 100 (90.degree.
minimum rotation (+/-45.degree.).
[0028] The probe tubing assembly 110 is primarily made from
stainless steel. There are illustratively two bushings that guide
the water tubing to the transducer as well as provide support for
access to the coupling of the transducer shaft 109 and the
hexagonal shaft. The transducer shaft 109 is coupled to the hex
shaft (mentioned above) and is able to rotate and translate for
both imaging and continuous HIFU Treatment.
[0029] The probe tip illustratively includes two components: a main
stainless steel tubing body 110 shown in FIG. 1 which
illustratively has a 17 mm diameter or less to fit into an 18 mm
trocar, and a removable tip assembly 111 shown in FIGS. 2-4. The
main tubing body 110 illustratively has a threaded end 113 that
connects with threads formed in distal end 114 of the removable tip
111. The removable tip 111 also includes a distal end 116 having a
rounded tip 148 coupled thereto. The internal threading 115 (best
shown in FIG. 3) has the threads removed on opposite sides of the
tubing (see area 119) to permit the transducer to pass into the
tip. A coupling water bolus 118, a curved thin stainless steel shim
material 120, and two short pieces of very thin heat shrink tubing
122, 124 complete the illustrated removable tip 111 components. The
removable tip 111 is illustratively made from stainless steel but
may be molded from a resin such as Ultem.RTM. resin or other
suitable material. The bolus 118 is illustratively formed from a
polyurethane membrane or condom inserted over the end of probe tip
111. Bolus 118 is illustratively a tubular membrane with a sealed
end 141 best shown in FIG. 3. A shim 120 is then located over the
bolus membrane 118 on an opposite side of a treatment aperture 117.
Shim 120 is coupled to the tip 111 only by two heat shrinking tubes
122 and 124 best shown in FIGS. 3 and 4. Tubes 122 and 124 have a
thickness of about 4-5 thousandths of an inch. Illustratively the
membrane is made from HT-9 material available from Apex Medical.
The heat shrink tubing is illustratively made from ultra thin
polyester tubing and is made by Advanced Polymers. The removable
tip assembly 111 is designed to be disposable (USP--Class VI) and
sterile. Sterilizing the removable tip can be achieved via ethylene
oxide (EO) sterilization or gamma sterilization.
[0030] The tubes 122 and 124 are very thin and facilitate insertion
of the probe tip 111 through the trocar 60. Tubes 122 and 124
minimize the thickness of the tip 111 which is desirable for
laparoscopic procedures. Additional adhesives or other securing
means are not required to secure the shim 120 to the bolus 118 or
tip 111.
[0031] As discussed above, the removable tip 111 includes a housing
135 formed to include an opening or aperture 117. The transducer
100 is movable within the aperture as controlled by the drive
mechanism 92 and controller 93 to provide the HIFU Therapy.
Transducer 100 is configured to emit ultrasound energy through the
aperture 117 in the direction of arrow 137 which is referred to as
a treatment direction.
[0032] The housing 135, the tubes 122, 124 and the shim 120 work
together to cause the bolus 118 to expand only in the treatment
direction 137 in FIG. 4. The shim 120 forces the bolus 118 to
expand in the direction of the opening 117 in the removable tip 111
as shown in FIG. 2. The heat shrink tubes 122, 124 hold the shim
120 in the desired position as well as constraining the ends of the
bolus membrane 118. The expansion of the water bolus 118
acoustically couples the ultrasound to the patient. It also changes
the location of the transducer focus with respect to the target
targeted area, thereby changing the position of the targeted tissue
with respect to distance from the transducer 100.
[0033] As discussed above, the stainless steel shim 120 is an
element used to control expansion of the water bolus 118 during a
treatment. Removing the stainless steel shim 120 would result in a
uniform expansion of the water bolus 118 around the probe tip 111
in the presence of no external objects. With no shim 120 applying
pressure to hold the probe against tissue for treatment at a
specific distance would result in the bolus 118 reacting by
shifting water behind the probe tip and away from the tissue. This
may result in a poor and uncontrolled acoustic coupling of the
transducer 100 to the tissue and the inability to accurately place
the HIFU Treatment zones in their desired locations.
[0034] The bolus membrane material 118 illustratively has a memory
characteristic. This provides a substantially flat elevated
position of bolus 118 above aperture 117 for uniform contact and
coupling with a larger tissue area. Once the probe 90 is positioned
within a body, a controller controls drive mechanisms to move the
transducer 100 to provide HIFU Therapy.
[0035] Providing a sterile, distilled, degassed water recirculation
system for cooling and acoustic coupling during treatment is
another illustrated aspect of the present invention. The water
should be sterile due to the required sterile surgical environment
and degassed for the successful operation of the HIFU
transducer.
[0036] The present invention contains components that work together
both inside and outside the sterile fields during the procedure.
For instance a water reservoir 200 is placed under a conventional
chiller which is located outside the sterile field as shown in FIG.
6. However, the degassed water inside the reservoir 200 remains
sterile because it only passes through a sterile environment. The
inside of the tubing is sterile thus the use of a non-sterile
peristaltic pump 208 maintains the sterility of the water. After
passing through the pump 208, the tubing enters the sterile field
surrounding the patient. The tubing is connected to the back of the
probe and water is pumped through the water bolus 118 and back out
to the water reservoir 200.
[0037] The reservoir 200 and tubing are illustratively produced as
a first sterile kit in an enclosed, sealed package 204 with the
tubing primed with sterile, degassed water as shown in FIG. 5A. A
second sterile kit in an enclosed, sealed package 206 contains the
components needed to prime the probe 111 and control the volume of
water within the water bolus 118. The second kit 206 illustratively
includes a female luer lock 207, a syringe 252, a stopcock 253, a
filled 125 mL bottle 250 of distilled, degassed sterile water,
sterile ultrasound coupling gel, o-rings and the removable probe
tip 111 discussed earlier as illustrated in FIG. 5B. Since the
probe tip 111 and everything that comes in contact with it must be
sterile, both of these kits are sealed in sterile packaging 204,
206 (such as Tyvek material) and are gamma irradiated.
[0038] The water reservoir 200 acts as a heat sink in order to
maintain the temperature of the transducer at safe operating levels
(below approximately 30.degree. C.). In addition, the water
reservoir 200 is made from a rigid material in order to maintain a
constant volume which is needed for control of the water bolus 118
height. The water bolus 118 provides a pressure release surface so
the pressure within the water bolus 118 is close to zero gauge
pressure. A peristaltic pump 208 illustratively creates either a
vacuum or a positive pressure within the water reservoir 200 and
the reservoir 200 must be able to withstand this pressure. The
addition or subtraction of water to the water reservoir 200 results
in changes to the water bolus 118 volume. Glass was illustratively
chosen for the water reservoir 200 because of its rigid properties
as well as the ability to maintain the degassed nature of the water
compared to plastic (several months) over long periods of time
(shelf life).
[0039] The water reservoir 200 is illustratively large enough, for
example four liters in size, to act as a heat exchanger and remove
heat from the water re-circulated to the probe. Therefore, a
conventional active chiller does not need to be used in order to
cool the water. Conventional chillers are typically not sterilized.
Therefore, if the chiller was used, sterility of the water
re-circulated to the pump would be broken. The large thermal mass
provided with the water within reservoir 200 provides a suitable
heat sink.
[0040] The preparation for a typical surgical procedure involves
the following steps: [0041] 1) Placing all contents of the two kits
204, 206 within the sterile field. [0042] 2) Attaching the probe
tip 111 to the probe [0043] 3) Priming the probe tip using a
syringe and the additional bottle of degassed, distilled, sterile
water. [0044] 4) Attaching the tubing to the main probe body 110.
[0045] 5) Passing the water reservoir 200 out of the sterile field,
hanging it below the chiller (or other desired location), and
placing the pump compatible tubing 222 through the peristaltic pump
208. [0046] 6) Filling the syringe 252 with degassed, distilled,
sterile water from bottle 250, attaching the stopcock 253 and
passing the syringe 250 out of the sterile field. This syringe 252
is then attached to the third tube 240 coming out of the top cap
220 of the water reservoir 200 to control the bolus water volume.
[0047] 7) Turn on the pump 208. [0048] 8) Remove all air bubbles
from the probe tip housing. [0049] 9) Inflate the water bolus 118
and shape the bolus 118 for the treatment, see FIG. 2. The water
bolus material 118 will "remember" the shape it took when it was
last inflated. [0050] 10) Coat the water bolus 118 and tip 111 with
ultrasound coupling gel. [0051] 11) Deflate the water bolus 118 for
insertion into the trocar 60 using the syringe 252, now outside of
the sterile field. [0052] 12) Position probe and adjust the water
bolus 118 to obtain the desired transducer/probe
positioning/coupling.
[0053] Referring to FIGS. 5A and 6, the water reservoir 200
illustratively provides a large volume of water, preferably about
four liter(s) held within the glass container or reservoir 200. The
reservoir 200 is sealed with a cap 220. A first tube section 222 is
coupled to cap 220 by a connector 224. Connector 224 is coupled to
an internal tube 226 having an open end located near a bottom of
the reservoir 200. Illustratively, tube section 222 is special
tubing made from C-Flex.RTM. by Masterflex.RTM. designed to fit
within the pump 208. Tube 222 is coupled to another tube section
225 by connectors 227. An end 228 of tube 225 is configured to
couple to a fitting on the probe tip 111. Tube section 230 includes
an end 229 that couples to the other fitting of probe tip 111. Tube
section 230 extends from the probe tip 111 back to a second
connector 232 on cap 220. Tube section 230 is coupled to an
internal tube 234 located within reservoir 200 and provides return
fluid to the reservoir 200 from the bolus 118. Illustratively, tube
sections 226 and 234 extend more than half way down into the fluid
within the reservoir 200. The water is degassed, distilled and
sterile. If desired, the water could be deionized. In the
illustrated embodiment, tube 226 is located near the bottom of
reservoir 200. The bottom of reservoir 200 likely contains the
coolest water and is spaced apart from any air in the reservoir 200
that collects at the top of reservoir 200 near cap 220. As
discussed above, the last few feet of the end portions of tubes 225
and 230 remain inside the sterile field (see FIG. 6) while the
remaining components of the kits are passed outside the sterile
field. A syringe 252 is configured to be coupled to connector 236
which is in turn, coupled to cap 220 by a connector 238 and a tube
section 240. Normally open pinch clamps 223 and 231 are coupled to
tubes 222 and 230, respectively. If needed, pinch clamps 223 and
231 and be closed to stop the flow of water therethrough. For
instance, if the surgeon needs to replace the probe tip 111, the
surgeon first turns the pump off, then pinch the clamps 223 and 231
can be closed to seal the tubes 222 and 230, respectively.
[0054] As discussed above, before the tube sections 225 and 230 are
coupled to the probe tip 111, the probe tip is first primed using a
syringe 252 and fluid from a container 250 located in kit 206. The
bolus 118 is filled with the sterile water and the syringe is also
filled or loaded with sterile water and transferred outside the
sterile field and connected to connector 236 to control the
expansion of bolus 118 from outside the sterile field.
[0055] The prediction on the size of the reservoir 200 required for
adequate cooling is based on heat transfer from a probe [output
level at maximum, TAP (total acoustic power)=39 W] an provides a
conservative estimate of heating for a volume of water starting at
room temperature (25 C).
[0056] Question: How many cycles (15 minutes HIFU ON and 2 minutes
HIFU OFF) can 3.2 L of water starting at room temperature (25 C)
withstand before reaching 30 C? Theoretical Prediction based on
heat capacity of the water: 2.5 cycles to raise the temperature to
30 C.
.DELTA.T=Pt/(c.rho.V)
Where the variables are defined as:
[0057] P=power (assume efficiency of transducer is 50% thus this is
equal to TAP)
[0058] V=volume of the water reservoir
[0059] t=time
[0060] c=specific heat of water
[0061] .rho.=density of water
[0062] .DELTA.T=change in temperature
Experiment: 4 cycles were completed before raising the temperature
of the water to 30 C (similar results were found for a second
experiment). Thus a gallon (3.8 L) of water at or below room
temperature should suffice to cool the probe adequately for a
procedure of reasonable length.
[0063] Upon completion of the above steps the user plans and
performs the HIFU treatment using software running on the
Sonablate.RTM. 500 system connected to the laparoscopic probe 90.
The physician uses the real time image capability of the
laparoscopic probe to aid in the final placement of the probe. When
the positioning is complete, an articulated arm holding the probe
90 is locked into place. The physician judges a real time image in
both sector (rotating side to side transverse to the probe axis)
and linear (back and forth along probe axis) motion ("bi-plane"
images). Depending on the positioning and physician preference,
either the linear or sector image may be chosen or the physician
may alternate between the two. After physically moving the probe,
fine tuning to the position of the treatment region is achieved by
moving the treatment region using software controls 301. This
adjusts the position of transducer 100 within the probe housing 135
resulting in fine tuning of the tissue treatment area. FIG. 7
displays an illustrated user interface with the treatment zones
moved from the default center positions.
[0064] Once the treatment zone is positioned and resized by the
physician to cover the desired tissue region (for example, a
tumor), the HIFU Treatment is started and the probe begins to apply
HIFU Therapy within the chosen region. The transducer trajectory is
calculated by a series of algorithms that permit it to cover the
entire treatment zone in a pattern illustrated in FIGS. 8A-8C. The
trajectory is also designed to ensure constant equal trace spacing,
meaning the spacing between the lines of the trajectory is
substantially uniform throughout the region.
[0065] FIGS. 8A-8C illustrate an exemplary pattern of HIFU Therapy
application during HIFU Treatment with the laparoscopic probe. FIG.
8A is representative of the treatment path 175 soon after the start
of the treatment. FIG. 8B is representative of the treatment path
175 midway, and FIG. 8C is representative of the treatment path 175
near the end. The tracings depict the linear (vertical) and the
sector (angular) positions of the transducer 100 during the
treatment. This user feedback is continuously updated during the
treatment. Once the treatment starts, the transducer is
continuously moving at constant speed and continuously applying
HIFU to the tissue treatment area.
[0066] FIG. 9 illustrates an image update taken with the imaging
transducer during treatment. The upper panels show the tissue
before application of HIFU Treatment. The lower panels display the
images acquired during the HIFU Treatment. Treatment progress may
be gauged by the tracing in position 300 the lower left corner, by
the time remaining 302 along the right side of the screen, and by
the HIFU-induced echogenic tissue changes visible in the "after"
image 303.
[0067] The screenshot shown in FIG. 9 was taken about half way
through a HIFU Treatment. In the bottom left HIFU run time
indicates that this particular treatment has lasted 1 minute and 55
seconds and the time remaining 302 (on the right side) shows 57
seconds. Once the HIFU Treatment is complete, the water reservoir
200 and associated tubing along with any components of the kits
(including the removable probe tip 111) that were used are
discarded.
[0068] The treatment algorithms of the present invention are
designed to substantially fill a treatment zone or region selected
by the physician. Often, these treatment zones or regions are not
symmetrically shaped. Software of the present invention controls a
controller 93 to move the transducer 100 back and forth in the
direction of double headed arrow 106 in FIG. 1 and to rotate the
transducer about its axis 107 as illustrated by arrow 108 in FIG. 1
to provide a continuous treatment path within the selected
treatment region. As illustrated in FIGS. 8A, 8B and 8C, the
transducer moves at constant speed, (about 1-2 mm/sec.) to provide
spacing between the treatment path followed by the transducer of
about 1.5-2.0 mm. The algorithm is designed to keep the spacing
between adjacent portions of treatment path 175 substantially
constant as illustrated at 176 in FIG. 8A and to cross or intersect
a previous portion of the treatment path 175 at an angle as close
to 90 degrees as possible (see, for example, intersections 177 in
FIGS. 8B and 8C) to avoid retracing the path 175. This pattern of
path spacing at essentially 90 degree crossing provides a more
uniform heat distribution with respect to depth inside the
treatment region. When path 175 hits a boundary edge of a treatment
zone defined by a physician, the path 175 changes directions at an
angle of about 90.degree.. In FIGS. 8A-8C, the physician defined a
square treatment zone best shown by the filled zone in FIG. 8C. It
is understood, however, that the treatment regions may be defined
in any desired shape (typically rectangular) and are often not
square.
[0069] In the illustrated HIFU Therapy, the trajectory stays within
bounds parallel to the trajectory path. The bounds limit is a
floating-point value specified in millimeters and placed in a
property file. Default is 1.5 millimeters, checked every 200
milliseconds, but not checked within 200 milliseconds of an image
update, end of move, or corrective action sweeps. Upon receiving a
2.sup.nd sequential out-of-bounds reading, the RF power is turned
off and the probe is commanded to perform a linear and sector
sweep. A level 1 corrective action taken flag will be set and
therapy resumed. Upon reaching the end of the current move, the
corrective action flag will be reset. If two consecutive
out-of-bounds readings are again detected before the end of the
move, the probe is homed, a level 2 corrective action flag is set,
and therapy will continue. If two consecutive out-of-bounds
readings are again detected before the move is completed, therapy
is stopped. This "intelligent" checking is incorporated to reduce
treatment interruptions due to single errors, allows for graceful
degradation and minimizes physician interaction with the mechanical
aspects of the probe. If the probe, even after recovery efforts,
still fails, this provides an indication of tissue blocking the
transducer, or a mechanical problem.
[0070] During a single move, a check is made to make sure the
distance to the destination is decreasing. The required decrease
value is a floating-point value is specified in millimeters and
placed in a property file. Default is 0.2 millimeters, checked
every 400 milliseconds. Not checked within 200 milliseconds of an
image update. Corrective action similar to paragraph [0050] will be
taken in the event of errors.
[0071] After an individual move starts, the controller 93 makes
sure it finishes within the move time specified in the trajectory
list +/-25% and +/-500 milliseconds. Tolerance values are placed in
a property file. The controller 93 tracks the move number and makes
sure the move number increments properly. Checked every 200
milliseconds. Corrective action similar to paragraph [0050] will be
taken in the event of errors.
[0072] A data validation check is performed at the start of
therapy, after each image update, and after a pause therapy. The
controller 93 makes sure that no move exceeds the maximum
theoretical move time and no linear and sector data points are
outside the therapy treatment area. If an error is found the
controller 93 reconstructs the data structure and checks again. In
the event of error, the trajectory data is assumed corrupted and
therapy is stopped. The controller 93 makes sure that resume data
points are within 1.5 millimeters of the therapy bounds, value
placed in a property file.
[0073] A watchdog timer is reprogrammed to cut off RF output if it
is not kicked at a 1 Hz rate. If the emergency stop button located
on the Sonablate.RTM. 500 console is pressed, the controller 93
pauses therapy and display the emergency stop icon. The pump 208 is
also stopped.
[0074] If the probe temperature goes into the yellow zone, the
controller flashes the temperature icon and turns pump 208 on. The
controller 93 stops therapy if in the red zone upon second
sequential reading. The probe temperature is read once every 5
seconds. Illustratively, the yellow zone temperature ranges from 25
to 30.degree. C. The red zone temperature is above 30.degree.
C.
[0075] If the reverse watts percent is greater than the maximum
reverse watts percent, the controller 93 stops therapy on a second
sequential reading. Read once a second. Absolute value watt limits
will also be checked to avoid false alarms at low power (10-15
watts). No test within 500 milliseconds of an RF on/off transition
or power output change.
[0076] If the RF power exceeds the probe maximum for two
consecutive readings, the controller 93 stops therapy. Median power
readings are used based on readings checked once per second. No
test within 500 milliseconds of an RF on/off transition or power
output change.
[0077] The controller 93 monitors the watchdog timer output to make
sure it is following RF output commands. If detected, the
controller 93 runs the code to put the watchdog timer back in the
verification mode. Resume therapy. If additional errors detected,
stop therapy.
[0078] Paragraphs [0050] to [0058] give an illustration of the
built-in safety checks and error recovery algorithms designed
mainly to turn the HIFU delivery OFF in the case of a failure, or
to gracefully recover from a motor/transducer positions error due
to probe tolerances, probe/tissue interactions, or probe
failure.
[0079] The efficacy, performance, utility, and practicality of
these newly developed Sonablate.RTM. Laparoscopic (SBL) probes and
treatment methodologies was evaluated in-vivo using a pig model.
Pre-selected kidney volumes (1 cm.sup.3 to 18 cm.sup.3) were
targeted for ablation (including the upper and lower poles, and
regions adjacent to the collective system and ureter), and treated
laparoscopically with HIFU in a sterile environment using the SBL
probes. Integrated ultrasound image guidance was used for probe
positioning, treatment planning, and treatment monitoring. The
kidneys were removed either 4 or 14 days post-HIFU, and the
resulting lesions were compared to the treatment plan. Results
indicate that HIFU can be used laparoscopically to ablate kidney
tissue at a rate of approximately 1 to 2 cm.sup.3/minute, even in
highly perfused organs like the kidney. Results also indicate that
treatment methodologies vary depending on the target location,
intervening tissue, probe location, and port location.
[0080] The following provides an illustrative example of the
treatment path generation software used to determine the transducer
path based on a treatment plan/region arbitrarily selected by the
physician:
TABLE-US-00001 % trajectory12 % rs v1.2 10/6/2004 clear close all %
Notes: % Results contained in the variable "points", correctly
ordered, in [mm,mm]. linsta=0; %mm (0 to 25) linsto=10; %mm (25 to
50) secsta=-5; %deg (-45 to 3) (minimum 6 degree extent...)
secsto=5; %deg (3 to 45) fl=35; %mm; focal length sp=2; %mm;
spacing of traces; put in property file gspeed=1.5; %mm/s; global
speed; put in property file wstandoff=15; %mm; water standoff;
determine from "rectal wall distance measurement" plt1=1; %plot
plt2=1; %plot lmax=linsto-insta; %mm; maximum linear travel V1=1.5;
%mm/s; initial guess linear amax=(secsto-secsta)/360*(2*pi*fl);
%mm; maximum sector travel at specified focal length Va=1.5; %mm/s;
initial guess angle fe=12; %mm; focal extent disp(` `);
disp([`Linear travel: ` num2str(lmax) ` mm.`]); disp([`Angular
travel: ` num2str(amax) ` mm.`]); vincr=0.01; % velocity change
T=100; t=linspace(0,T,1000); %s tincr=0.02; sperror=0.1; d=1000;
wc=0; while abs(d-sp)>sperror, x=rem(Va*t,2*amax);
y=rem(Vl*t,2*lmax); for i=1:length(t), if x(i)>amax,
x(i)=2*amax-x(i); end if y(i)>lmax, y(i)=2*lmax-y(i); end end %
determine 1st slope... m1=(y(2)-y(1))/(x(2)-x(1)); c1=0; % now find
the next sets of points at which the slope is the same as m1...
m2=0; count=3; while y(count) > y(2), count=count+1; end
count=count+1; % m2=(y(count+1)-y(count))/(x(count+1)-x(count));
m2=m1; c2=y(count+1)-m2*x(count+1); x2=x(count); y2=y(count); % now
find the spacing between these two lines... mp=-1/m1;
xd=c2/(mp-m2); yd=mp*xd; d=sqrt(xd{circumflex over (
)}2+yd{circumflex over ( )}2); % show results for current
iteration... if plt1==1, figure(1); clf; plot(x,y,`.`); hold on;
line([0 amax],[0 0],`Color`,[1 0 0],`LineWidth`,2); line([0
amax],[lmax lmax],`Color`,[1 0 0],`LineWidth`,2); line([0 0],[0
lmax],`Color`,[1 0 0],`LineWidth`,2); line([amax amax], [0
lmax],`Color`,[1 0 0],`LineWidth`,2); axis(-20 amax+20 -20
lmax+20]); axis equal line([0 xd],[0 yd],`Color`,[0 1
0],`LineWidth`,2); plot(xd,yd,`go`); plot(x2,y2,`mo`); drawnow; end
Va=Va+vincr; wc=wc+1; end Va=Va-vincr; % Now we know the parameters
that will generate parallel lines Vl and Va... % disp([wc sp d Vl
Va]); % Find the points in the correct order... tp=[0 tincr
tincr*2]; count=2; points=[0 0]; done=0; while done==0,,
xp=rem(Va*tp,2*amax); yp=rem(V1*tp,2*lmax); for i=1:3, if
xp(i)>amax, xp(i)=2*amax-xp(i);end if yp(i)>lmax,
yp(i)=2*lmax-yp(i);end end m1x=xp(2)-xp(1); m2x=xp(3)-xp(2);
m1y=yp(2)-yp(1); m2y=yp(3)-yp(2); if sign(ml x) ~=sign(m2x),
points(count, 1:2)=[xp(2) yp(2)]; count=count+1; end if sign(m1y)
~=sign(m2y), points(count, 1:2)=[xp(2) yp(2)]; count=count+1; end
tp=tp+tincr; % check to see when we are done, be checking if the
last point is close to any of the previous points... mindelta=1000;
for i=1:count-2,
delta=sqrt((points(count-1,1)-points(i,1))+2+(points(count-1,2)-point-
s(i,2))+2); if delta<mindelta, mindelta=delta; end end if
mindelta<(sp-sperror), done=1; end end % shift points...
points(:,1)=points(:,1)+(secsta/360*2*pi*fl);
points(:,2)=points(:,2)+linsta; if plt2==1, figure(2); clf;
plot(points(:,1),points(:,2),`bo`); hold on
plot(points(:,1),points(:,2),`b`);
plot(points(1,1),points(1,2),`go`);
plot(points(count-1,1),points(count-1,2),`ro`); axis([-35 -5 55]);
xlabel([`Angular distance in focal plane [mm]`); ylabel(`Linear
distance [mm]`); axis equal; end % determine the total time and
travel distance... dtot=0; for i=1:count-2,
dtot=dtot+sqrt((points(i+1,1)-points(i,1))+2+(points(i+1,2)-points(i,2))-
+2); end disp(``);
V(secsto-secsta)/360*pi*((fl+fe/2)+2-wstandoff+2)*lmax/1000;
disp([`Total travel: ` num2str(dtot) ` mm.`]); disp([`Therapy time:
` num2str(dtot/gspeed) ` s (` num2str(dtot/gspeed/60) ` min).`]);
disp([`Volume treated: ` num2str(V) ` cm{circumflex over ( )}3(`
num2str(V/(dtot/gspeed/60)) ` cm{circumflex over ( )}3/min), with a
` num2str(wstandoff) ` mm water standoff.`]); disp([`Focal length:
` num2str(fl) ` mm.`]); disp([`Line segments: ` num2str(count-2)]);
disp([`Line spacing: ` num2str(sp) ` mm.`]); disp([`Linear speed: `
num2str(gspeed) ` mm/s.`]); disp(``);
[0081] It is understood that the above example is illustrative only
and that other control software may be used in accordance with the
present invention.
[0082] Although the invention has been described in detail with
reference to certain illustrated embodiments, variations and
modifications exist within the spirit and scope of the invention as
described and defined in the following claims.
* * * * *