U.S. patent application number 15/674767 was filed with the patent office on 2017-11-23 for microwave field-detecting needle assemblies, methods of manufacturing same, methods of adjusting an ablation field radiating into tissue using same, and systems including same.
The applicant listed for this patent is COVIDIEN LP. Invention is credited to JOSEPH D. BRANNAN.
Application Number | 20170333129 15/674767 |
Document ID | / |
Family ID | 46319229 |
Filed Date | 2017-11-23 |
United States Patent
Application |
20170333129 |
Kind Code |
A1 |
BRANNAN; JOSEPH D. |
November 23, 2017 |
MICROWAVE FIELD-DETECTING NEEDLE ASSEMBLIES, METHODS OF
MANUFACTURING SAME, METHODS OF ADJUSTING AN ABLATION FIELD
RADIATING INTO TISSUE USING SAME, AND SYSTEMS INCLUDING SAME
Abstract
A microwave field-detecting needle assembly includes a needle
assembly. The needle assembly includes a distal portion, a proximal
portion, and a junction member disposed between the distal portion
and the proximal portion. The junction member includes a recess
defined therein. The needle assembly also includes a rectifier
element disposed in the recess. The rectifier element includes a
first terminal electrically coupled to the distal portion and a
second terminal electrically coupled to the proximal portion.
Inventors: |
BRANNAN; JOSEPH D.; (LYONS,
CO) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
COVIDIEN LP |
MANSFIELD |
MA |
US |
|
|
Family ID: |
46319229 |
Appl. No.: |
15/674767 |
Filed: |
August 11, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14727950 |
Jun 2, 2015 |
9743985 |
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15674767 |
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12977415 |
Dec 23, 2010 |
9044253 |
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14727950 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61B 2018/0072 20130101;
A61B 2018/1823 20130101; H01Q 1/248 20130101; A61B 18/1815
20130101; Y10T 29/49117 20150115; A61B 5/0507 20130101; A61B
2018/00642 20130101; A61B 2018/00755 20130101; A61B 2018/00714
20130101; G01R 29/0878 20130101; A61B 2018/1425 20130101; A61B
18/1477 20130101; A61B 5/4836 20130101; G01R 29/0814 20130101; A61B
2018/00577 20130101; A61B 2018/1869 20130101; A61B 2018/00702
20130101; A61N 5/045 20130101; A61B 2018/00767 20130101; A61B
2018/1427 20130101; A61B 2018/00761 20130101; G01R 29/0871
20130101 |
International
Class: |
A61B 18/18 20060101
A61B018/18; G01R 29/08 20060101 G01R029/08; A61B 5/00 20060101
A61B005/00; A61B 18/14 20060101 A61B018/14; A61N 5/04 20060101
A61N005/04; H01Q 1/24 20060101 H01Q001/24; A61B 5/05 20060101
A61B005/05 |
Claims
1-20: (canceled)
21. A microwave ablation control system comprising: an energy
applicator insertable into tissue; a control unit a microwave
field-detecting needle in operable communication with the control
unit, wherein the microwave field-detecting needle is separately
insertable into tissue from the energy applicator and includes: a
needle assembly including a distal portion, a proximal portion, and
a junction member disposed between the distal portion and the
proximal portion, the junction member including a recess defined
therein; and a rectifier element disposed in the recess and
including a first terminal electrically coupled to the distal
portion and a second terminal electrically coupled to the proximal
portion.
22. The microwave ablation control system of claim 21, wherein the
rectifier element is configured to convert alternating current (AC)
to direct current (DC).
23. The microwave ablation control system of claim 22, wherein the
rectifier element includes at least one of a diode, a Zener diode,
a Schottky diode, or a tuner diode.
24. The microwave ablation control system of claim 21, wherein the
junction member is coupled by a mechanical coupling to at least one
of the distal portion or the proximal portion of the needle
assembly.
25. The microwave ablation control system of claim 21, further
comprising a handle assembly operably coupled to the proximal
portion of the needle assembly.
26. The microwave ablation control system of claim 25, wherein the
distal portion includes a first outer-conductor structure.
27. The microwave ablation control system of claim 26, wherein the
first outer-conductor structure defines a first chamber portion
disposed at a distal portion of the first outer-conductor
structure.
28. The microwave ablation control system of claim 27, wherein the
first outer-conductor structure defines a second chamber portion
disposed in communication with the first chamber portion and
includes an opening disposed at a proximal portion of the first
outer-conductor structure.
29. The microwave ablation control system of claim 28, wherein the
first outer-conductor structure includes an end cap disposed at the
distal portion of the first outer-conductor structure, and at least
a portion of the first chamber portion is disposed within the end
cap.
30. The microwave ablation control system of claim 29, wherein the
proximal portion of the needle assembly includes a second
outer-conductor structure.
31. The microwave ablation control system of claim 30, further
comprising an inner-conductor pin, wherein the second
outer-conductor structure defines a longitudinally-extending
chamber configured to receive the inner-conductor pin
therethrough.
32. The microwave ablation control system of claim 31, wherein the
inner-conductor pin includes a retaining portion configured to
threadedly engage with the first chamber portion.
33. The microwave ablation control system of claim 32, wherein the
handle assembly includes an electrical circuit electrically coupled
to the inner conductor pin.
34. The microwave ablation control system of claim 24, wherein the
mechanical coupling between the junction member and at least one of
the distal portion or the proximal portion is a threaded coupling.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 14/727,950, filed on Jun. 2, 2015, which is a
continuation of U.S. patent application Ser. No. 12/977,415, now
U.S. Pat. No. 9,044,253, filed on Dec. 23, 2010, the entire
contents of each of which are hereby incorporated by reference
herein.
BACKGROUND
Technical Field
[0002] The present disclosure relates to electrosurgical devices
suitable for use in tissue ablation applications and, more
particularly, to microwave field-detecting needle assemblies,
methods of manufacturing the same, methods of adjusting an ablation
field radiating into tissue using the same, and systems including
the same.
Discussion of Related Art
[0003] Treatment of certain diseases requires the destruction of
malignant tissue growths, e.g., tumors. Electromagnetic radiation
can be used to heat and destroy tumor cells. Treatment may involve
inserting ablation probes into tissues where cancerous tumors have
been identified. Once the probes are positioned, electromagnetic
energy is passed through the probes into surrounding tissue.
[0004] In the treatment of diseases such as cancer, certain types
of tumor cells have been found to denature at elevated temperatures
that are slightly lower than temperatures normally injurious to
healthy cells. Known treatment methods, such as hyperthermia
therapy, heat diseased cells to temperatures above 41.degree. C.
while maintaining adjacent healthy cells below the temperature at
which irreversible cell destruction occurs. These methods involve
applying electromagnetic radiation to heat, ablate and/or coagulate
tissue. Microwave energy is sometimes utilized to perform these
methods. Other procedures utilizing electromagnetic radiation to
heat tissue also include coagulation, cutting and/or ablation of
tissue.
[0005] Electrosurgical devices utilizing electromagnetic radiation
have been developed for a variety of uses and applications. A
number of devices are available that can be used to provide high
bursts of energy for short periods of time to achieve cutting and
coagulative effects on various tissues. There are a number of
different types of apparatus that can be used to perform ablation
procedures. Typically, microwave apparatus for use in ablation
procedures include a microwave generator that functions as an
energy source and a microwave surgical instrument (e.g., microwave
ablation probe) having an antenna assembly for directing energy to
the target tissue. The microwave generator and surgical instrument
are typically operatively coupled by a cable assembly having a
plurality of conductors for transmitting microwave energy from the
generator to the instrument, and for communicating control,
feedback and identification signals between the instrument and the
generator.
[0006] The particular type of tissue ablation procedure may dictate
a particular ablation volume in order to achieve a desired surgical
outcome. Ablation volume is correlated with antenna design, antenna
performance, antenna impedance, ablation time and wattage, and
tissue characteristics, e.g., tissue impedance.
[0007] Because of the small temperature difference between the
temperature required for denaturing malignant cells and the
temperature normally injurious to healthy cells, a known heating
pattern and precise temperature control is needed to lead to more
predictable temperature distribution to eradicate the tumor cells
while minimizing the damage to surrounding normal tissue. In some
cases, it may be difficult for the physician to determine when a
microwave ablation probe is inserted to a proper depth within
tissue, e.g., to reach the location of the ablation site and/or to
avoid unintended radiation exposure.
SUMMARY
[0008] The present disclosure relates to a microwave
field-detecting needle assembly including a needle assembly. The
needle assembly includes a distal portion, a proximal portion, and
a junction member disposed between the distal portion and the
proximal portion. The junction member includes a recess defined
therein. The needle assembly also includes a rectifier element
disposed in the recess. The rectifier element includes a first
terminal electrically coupled to the distal portion and a second
terminal electrically coupled to the proximal portion.
[0009] The present disclosure also relates to method of
manufacturing a needle assembly including the initial step of
providing an inner-conductor pin including a retaining portion
disposed at a distal end of the inner-conductor pin. The method
includes the steps of joining a first outer-conductor structure to
the retaining portion, and positioning a tubular sleeve member
overlying a length of the inner-conductor pin proximal to the
retaining portion. The tubular sleeve member includes a
longitudinally-extending internal chamber configured to receive at
least a portion of the inner-conductor pin therein. The method also
includes the steps of joining a junction structure to a proximal
end of the first outer-conductor structure, whereby the junction
structure is disposed around a portion of the tubular sleeve
member. The junction structure includes a recess defined therein.
The method also includes the steps of joining a second
outer-conductor structure to a proximal end of the junction
structure and positioning a rectifier element into the recess.
[0010] The present disclosure also relates to a method of
manufacturing a microwave field-detecting needle assembly including
the initial step of providing a handle assembly. The method
includes the step of providing a needle assembly. The needle
assembly includes a first outer-conductor structure coupled to an
inner-conductor pin, a junction structure disposed between the
first outer-conductor structure and a second outer-conductor
structure, and a rectifier element disposed in a recess defined in
the junction structure and having a first terminal electrically
coupled to the first outer-conductor structure and a second
terminal electrically coupled to the second outer-conductor
structure. The method also includes the step of electrically
coupling the inner-conductor pin and the second outer-conductor
structure to an electric circuit disposed within the handle
assembly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Objects and features of the presently-disclosed microwave
field-detecting needle assemblies, methods of manufacturing the
same, methods of adjusting an ablation field radiating into tissue
using the same, and systems including the same will become apparent
to those of ordinary skill in the art when descriptions of various
embodiments thereof are read with reference to the accompanying
drawings, of which:
[0012] FIG. 1 is a perspective view of microwave field-detecting
needle assembly including a needle assembly and a handle assembly
according to an embodiment of the present disclosure;
[0013] FIG. 2 is an enlarged, cross-sectional view of the indicated
area of detail of FIG. 1 showing a distal portion of the needle
assembly according to an embodiment of the present disclosure;
[0014] FIG. 3 is an enlarged view of the indicated area of detail
of FIG. 1 showing a schematic diagram of an electric circuit (shown
in phantom lines in FIG. 1) disposed within the handle assembly
according to an embodiment of the present disclosure;
[0015] FIG. 4 is perspective view of a microwave field-detecting
system including an embodiment of a microwave field-detecting
needle assembly and an embodiment of a control unit in accordance
with the present disclosure;
[0016] FIG. 5 is perspective view with parts separated of the
microwave field-detecting needle assembly of FIG. 1 according to an
embodiment of the present disclosure;
[0017] FIG. 6 is perspective view of an inner-conductor pin
including a distal end configured with a retaining portion
according to an embodiment of the present disclosure;
[0018] FIG. 7 is perspective view of a portion of a needle assembly
including a first outer-conductor structure coupled to the
retaining portion and disposed around a distal portion of the
inner-conductor pin shown in FIG. 6 according to an embodiment of
the present disclosure;
[0019] FIG. 8 is a perspective view of the portion of the needle
assembly of FIG. 7 shown with a tubular sleeve member disposed
around a length of the inner-conductor pin proximal to the threaded
portion according to an embodiment of the present disclosure;
[0020] FIG. 9 is a perspective view of the portion of the needle
assembly of FIG. 8 shown with a junction structure disposed around
a portion of the tubular sleeve member and threadedly coupled to
the proximal end of the first outer-conductor structure according
to an embodiment of the present disclosure;
[0021] FIG. 10 is a perspective view of the portion of the needle
assembly of FIG. 9 shown with a second outer-conductor structure
disposed around a proximal portion of the tubular sleeve member and
threadedly coupled to the distal end of the junction structure,
according to an embodiment of the present disclosure;
[0022] FIG. 11 is a perspective view of the portion of the needle
assembly of FIG. 10 shown with a rectifier element disposed
separately from and positioned above a rectifier-receiving recess
defined in the junction structure according to an embodiment of the
present disclosure;
[0023] FIG. 12 is a perspective view of the portion of the needle
assembly of FIG. 11 shown with the rectifier element disposed in
the rectifier-receiving recess according to an embodiment of the
present disclosure;
[0024] FIG. 13 is a perspective view of the portion of the needle
assembly of FIG. 12 shown with an outer jacket disposed around the
first outer-conductor structure, second outer-conductor structure
and the junction structure according to an embodiment of the
present disclosure;
[0025] FIG. 14 is a cross-sectional view of the portion of the
needle assembly of FIG. 13 according to an embodiment of the
present disclosure;
[0026] FIG. 15 is a schematically-illustrated representation of a
standing wave coupled to the needle assembly of FIG. 13 according
to an embodiment of the present disclosure;
[0027] FIG. 16 is a perspective view of a first side of another
embodiment of a needle assembly in accordance with the present
disclosure;
[0028] FIG. 17 is a perspective view of a second side of the needle
assembly of FIG. 16 according to an embodiment of the present
disclosure;
[0029] FIG. 18 is a schematic perspective view of an
electrosurgical system according to an embodiment of the present
disclosure;
[0030] FIG. 19 is a block diagram of an embodiment of the
electrosurgical power generating source of FIG. 18 in accordance
with the present disclosure;
[0031] FIG. 20 is a flowchart illustrating a method of method of
manufacturing a needle assembly according to an embodiment of the
present disclosure;
[0032] FIG. 21 is a flowchart illustrating a method of method of
manufacturing a microwave field-detecting needle assembly according
to an embodiment of the present disclosure; and
[0033] FIG. 22 is a flowchart illustrating a method of adjusting an
ablation field radiating into tissue.
DETAILED DESCRIPTION
[0034] Hereinafter, embodiments of microwave field-detecting needle
assemblies, methods of manufacturing the same, methods of adjusting
an ablation field radiating into tissue using the same, and systems
including the same of the present disclosure are described with
reference to the accompanying drawings. Like reference numerals may
refer to similar or identical elements throughout the description
of the figures. As shown in the drawings and as used in this
description, and as is traditional when referring to relative
positioning on an object, the term "proximal" refers to that
portion of the apparatus, or component thereof, closer to the user
and the term "distal" refers to that portion of the apparatus, or
component thereof, farther from the user.
[0035] This description may use the phrases "in an embodiment," "in
embodiments," "in some embodiments," or "in other embodiments,"
which may each refer to one or more of the same or different
embodiments in accordance with the present disclosure. For the
purposes of this description, a phrase in the form "A/B" means A or
B. For the purposes of the description, a phrase in the form "A
and/or B" means "(A), (B), or (A and B)". For the purposes of this
description, a phrase in the form "at least one of A, B, or C"
means "(A), (B), (C), (A and B), (A and C), (B and C), or (A, B and
C)".
[0036] Electromagnetic energy is generally classified by increasing
energy or decreasing wavelength into radio waves, microwaves,
infrared, visible light, ultraviolet, X-rays and gamma-rays. As it
is used in this description, "microwave" generally refers to
electromagnetic waves in the frequency range of 300 megahertz (MHz)
(3.times.10.sup.8 cycles/second) to 300 gigahertz (GHz)
(3.times.10.sup.11 cycles/second). As it is used in this
description, "transmission line" generally refers to any
transmission medium that can be used for the propagation of signals
from one point to another.
[0037] As it is used in this description, "ablation procedure"
generally refers to any ablation procedure, such as, for example,
microwave ablation, radiofrequency (RF) ablation, or microwave or
RF ablation-assisted resection. As it is used in this description,
"energy applicator" generally refers to any device that can be used
to transfer energy from a power generating source, such as a
microwave or RF electrosurgical generator, to tissue. For the
purposes herein, the term "energy applicator" is interchangeable
with the term "energy-delivery device".
[0038] As it is used in this description, "rectifier" generally
refers to circuit components that allow more electric current to
flow in one direction than in the other. Rectifiers may be made of
solid-state diodes, vacuum-tube diodes, mercury-arc valves, and
other components. Processes that make use of rectifiers include
rectification, which, simply defined, is the conversion of
alternating current (AC) to direct current (DC). As it is used in
this description, "diode" generally refers to electronic devices
that allow electric current to flow in only one direction, while
inhibiting current flow in the other. For the purposes herein, the
term "diode" is interchangeable with the term "rectifier".
[0039] As it is used in this description, "printed circuit board"
(or "PCB") generally refers to any and all systems that provide,
among other things, mechanical support to electrical components,
electrical connection to and between these electrical components,
combinations thereof, and the like.
[0040] As it is used in this description, "length" may refer to
electrical length or physical length. In general, electrical length
is an expression of the length of a transmission medium in terms of
the wavelength of a signal propagating within the medium.
Electrical length is normally expressed in terms of wavelength,
radians or degrees. For example, electrical length may be expressed
as a multiple or sub-multiple of the wavelength of an
electromagnetic wave or electrical signal propagating within a
transmission medium. The wavelength may be expressed in radians or
in artificial units of angular measure, such as degrees. The
electric length of a transmission medium may be expressed as its
physical length multiplied by the ratio of (a) the propagation time
of an electrical or electromagnetic signal through the medium to
(b) the propagation time of an electromagnetic wave in free space
over a distance equal to the physical length of the medium. The
electrical length is in general different from the physical length.
By the addition of an appropriate reactive element (capacitive or
inductive), the electrical length may be made significantly shorter
or longer than the physical length.
[0041] Various embodiments of the present disclosure provide
microwave field-detecting needle assemblies adapted to enable
physicians to detect microwave field intensity in proximity to an
energy-delivery device, e.g., to ensure patient and/or physician
safety and/or to provide for improved control over applied energy.
Microwave field-detecting needle assembly embodiments may be
implemented as passive devices. In some embodiments, microwave
field-detecting needle assemblies may be monitored by a stand-alone
control unit. Microwave field-detecting needle assembly embodiments
may be integrated into a feedback control loop within a microwave
ablation control system.
[0042] Microwave field-detecting needle assembly embodiments may be
suitable for utilization in open surgical applications. Embodiments
may be used in minimally invasive procedures, e.g., endoscopic and
laparoscopic surgical procedures. Portions of the
presently-disclosed microwave field-detecting needle assemblies may
be disposable, replaceable and/or reusable.
[0043] Various embodiments of the presently-disclosed microwave
field-detecting needle assembly are adapted to be coupled in
communication with a stand-alone control unit (e.g., 28 shown in
FIG. 4).
[0044] An electrosurgical system (also referred to herein as a
"microwave ablation control system") including an energy-delivery
device(s) and one or more microwave field-detecting needle
assemblies according to various embodiments is designed and
configured to operate at frequencies between about 300 MHz and
about 10 GHz. The presently-disclosed microwave ablation control
systems are suitable for microwave or RF ablation and for use to
pre-coagulate tissue for microwave or RF ablation-assisted surgical
resection. In addition, although the following description
describes embodiments of a microwave field-detecting needle
assembly capable of detecting electromagnetic radiation at
microwave frequencies, the teachings of the present disclosure may
also apply to electromagnetic radiation at RF frequencies or at
other frequencies.
[0045] FIGS. 1 through 3 show an embodiment of a microwave
field-detecting needle assembly (shown generally as 100 in FIG. 1).
Microwave field-detecting needle assembly 100 generally includes a
handle assembly 170 and a needle assembly 110. FIG. 3 shows a
schematic diagram of an electric circuit 300 (shown in phantom
lines in FIG. 1) disposed within a handle housing 174 of the handle
assembly 170. Needle assembly 110 is shown with parts separated in
FIG. 5.
[0046] As shown in FIGS. 1, 2 and 5, the needle assembly 110
generally includes a distal portion 130, a proximal portion 160,
and a junction member 150 disposed between the distal portion 130
and the proximal portion 160. In some embodiments, the distal
portion 130 and the proximal portion 160 align at the junction
member 150, which is generally made of a dielectric material. In
some embodiments, the junction member 150 may be configured to be
mechanically coupleable (e.g., threadedly coupleable) to the distal
portion 130 and/or the proximal portion 160. In some embodiments,
the distal portion 130 includes a first outer-conductor structure
30, the proximal portion 160 includes a second outer-conductor
structure 60, and the junction member 150 includes a junction
structure 50. The shape and size of the needle assembly 110 and the
handle assembly 170 may be varied from the configuration depicted
in FIG. 1.
[0047] As shown in FIGS. 2 and 5, needle assembly 110 includes an
inner-conductor pin 20, a tubular sleeve member 40 disposed around
at least a portion of the inner-conductor pin 20, a first
outer-conductor structure 30, a second outer-conductor structure
60, a junction structure 50 disposed between the first
outer-conductor structure 30 and the second outer-conductor
structure 60, and one or more rectifiers 58 disposed in one or more
recesses 56 defined in the junction structure 50. Inner-conductor
pin 20 has a suitable outer diameter "D.sub.1" (FIG. 5). The distal
end 22 of the inner-conductor pin 20 includes a retaining portion
23. In some embodiments, the retaining portion 23 may be externally
threaded. In one embodiment, the proximal end 21 of the
inner-conductor pin 20 is coupled to the handle assembly 170.
Inner-conductor pin 20 may be electrically coupled to an electric
circuit 300, which is described in more detail later in this
disclosure, disposed within the handle assembly 170.
[0048] Various components of the needle assembly 110 may be formed
of suitable, electrically-conductive materials, e.g., copper, gold,
silver, or other conductive metals or metal alloys having similar
conductivity values. Electrically-conductive materials used to form
the inner-conductor pin 20, the first outer-conductor structure 30
and/or the second outer-conductor structure 60 may be plated with
other materials, e.g., other conductive materials, such as gold or
silver, to improve their properties, e.g., to improve conductivity,
decrease energy loss, etc.
[0049] In some embodiments, the inner-conductor pin 20, the first
outer-conductor structure 30 and/or the second outer-conductor
structure 60 may be formed of a rigid, electrically-conductive
material, such as stainless steel. In some embodiments, the
inner-conductor pin 20 is formed from a first
electrically-conductive material (e.g., stainless steel) and the
first outer-conductor structure 30 and/or the second
outer-conductor structure 60 is formed from a second
electrically-conductive material (e.g., copper). In some
embodiments, the inner-conductor pin 20, the first outer-conductor
structure 30 and/or the second outer-conductor structure 60 may be
formed of a flexible, electrically-conductive material, such as
titanium.
[0050] Tubular sleeve member 40 includes a body 44 that defines a
longitudinally-extending internal bore or chamber 45 configured to
receive at least a portion of the inner-conductor pin 20 therein.
Body 44 has a suitable outer diameter "D.sub.2" as shown in FIG. 5.
Tubular sleeve member 40 may be formed from any suitable dielectric
material, including, but not limited to, ceramics, mica,
polyethylene, polyethylene terephthalate, polyimide,
polytetrafluoroethylene (PTFE) (e.g., TEFLON.RTM., manufactured by
E. I. du Pont de Nemours and Company of Wilmington, Del., United
States), glass, metal oxides or other suitable insulator, and may
be formed in any suitable manner. In the embodiment shown in FIG.
2, tubular sleeve member 40 is disposed around a length of the
inner-conductor pin 20 proximal to the retaining portion 23.
[0051] Junction member embodiments in accordance with the present
disclosure include a junction structure having one or more recesses
(e.g., one recess 56 shown in FIGS. 2, 5 and 9-12, or a plurality
of recesses 1656 shown in FIG. 16) defined therein. As best shown
in FIG. 11, the recess 56 is configured to receive a rectifier 58
therein. Rectifier 58 may include one or more diodes, e.g., Zener
diode, Schottky diode, tunnel diode and the like, and/or other
suitable component(s) capable of converting AC to DC.
[0052] Junction structure 50 may be formed of any suitable
elastomeric or ceramic dielectric material by any suitable process.
In some embodiments, the junction structure 50 may be formed of a
composite material having low electrical conductivity, e.g.,
glass-reinforced polymers. In some embodiments, the junction
structure 50 is formed by over-molding and includes a thermoplastic
elastomer, such as, for example, polyether block amide (e.g.,
PEBAX.RTM., manufactured by The Arkema Group of Colombes, France),
polyetherimide (e.g., ULTEM.RTM. and/or EXTEM.RTM., manufactured by
SABIC Innovative Plastics of Saudi Arabia) and/or polyimide-based
polymer (e.g., VESPEL.RTM., manufactured by E. I. du Pont de
Nemours and Company of Wilmington, Del., United States). Junction
structure 50 may be formed using any suitable over-molding compound
by any suitable process, and may include use of a ceramic
substrate.
[0053] In an embodiment, as best shown in FIG. 3, electric circuit
300 is disposed within the handle housing 174 of the handle
assembly 170. In one embodiment, electric circuit 300 may be formed
as a printed circuit board, with components thereof connected by
traces on an epoxy resin substrate.
[0054] Handle housing 174 provides a ground reference "G" for the
circuit 300. An indicator unit 4, or component thereof, is coupled
to the handle housing 174. Indicator unit 4 may include audio
and/or visual indicator devices to provide information/feedback to
a user. In the embodiment shown in FIGS. 1 and 3, the indicator
unit 4 is adapted to generate a visual signal and includes a light
source, such as a light-emitting diode 9. Indicator unit 4 may
additionally, or alternatively, be adapted to generate an audio
signal and may include an audio circuit with a speaker (not
shown).
[0055] The proximal end 21 of the inner-conductor pin 20 (shown in
cross section in FIG. 3) is electrically coupled to a first
terminal of a filter circuit 5. Filter circuit 5 includes a second
terminal electrically coupled to an amplifier circuit 7, and may
include a ground terminal electrically coupled to the handle
housing 174. Filter circuit 5 may include an RF filter block. In
one embodiment, the filter circuit 5 may be an
inductor-resistor-capacitor (LCR) low-pass filter that is adapted
to convert a rectified sinusoidal waveform from the rectifier
element(s) 58 into an electrical signal, which may be a DC voltage
signal representative of the detected microwave field
intensity.
[0056] As shown in FIG. 3, circuit 300 includes a power source 3
that is electrically coupled to the amplifier circuit 7. Power
source 3 may include a ground terminal electrically coupled to the
handle housing 174. Power source 3 may include any combination of
battery cells, a battery pack, fuel cell and/or high-energy
capacitor. A battery pack may include one or more disposable
batteries. In such case, the one or more disposable batteries may
be used as a primary power source for the amplifier circuit 7. In
some embodiments, a transmission line 11 (FIG. 1) is provided to
connect the microwave field-detecting needle assembly to a line
source voltage or external power source (shown generally as 2 in
FIG. 1), in which case a battery pack may be provided for use as a
backup power source.
[0057] FIG. 4 schematically illustrates an embodiment of a
microwave field-detecting system (shown generally as 10) that
includes a stand-alone control unit 28 operably coupled to a
microwave field-detecting needle assembly 400. Microwave
field-detecting needle assembly 400 is similar to the microwave
field-detecting needle assembly 100 of FIG. 1, except that
microwave field-detecting needle assembly 400 includes a handle
assembly 470 configured to operably couple the needle assembly 110
to a cable assembly 15. Cable assembly 15 may be any suitable
transmission line. Cable assembly 15 may include a proximal end 14
suitable for connection to the control unit 28.
[0058] Handle assembly 470 includes an indicator unit 412 that is
suitably configured to provide information/feedback to a user.
Indicator unit 412 is similar to the indicator unit 4 shown in FIG.
3 and further description thereof is omitted in the interests of
brevity. The shape and size of the handle assembly 470 and the
indicator unit 412 may be varied from the configuration depicted in
FIG. 4.
[0059] Control unit 28 may include a user interface 27 in operable
communication with a processor unit 29. User interface 27 may
include audio and/or visual indicator devices to provide
information/feedback to a user. Processor unit 29 may be any type
of computing device, computational circuit, or any type of
processor or processing circuit capable of executing a series of
instructions that are stored in a memory (not shown) associated
with the processor unit 29. Processor unit 29 may be adapted to run
an operating system platform and application programs. Microwave
field-detecting needle assembly 400 and the control unit 28 may
utilize wired communication and/or wireless communication. In the
embodiment illustrated in FIG. 4, the microwave field-detecting
needle assembly 400 is electrically connected via the cable
assembly 15 to a connector 16, which further operably connects the
microwave field-detecting needle assembly 400 to a terminal 19 of
the control unit 28.
[0060] FIG. 5 shows the needle assembly 110 with parts separated in
accordance with the present disclosure. As described above with
reference to FIG. 2, the needle assembly 110 includes an
inner-conductor pin 20, first outer-conductor structure 30, second
outer-conductor structure 60, tubular sleeve member 40, junction
structure 50, and one or more rectifiers 58.
[0061] As shown in FIG. 5, the first outer-conductor structure 30
defines a first chamber portion 36 and a second chamber portion 35.
First chamber portion 36 is disposed at the distal end 32 of the
first outer-conductor structure 30. Second chamber portion 35 is
disposed in communication with the first chamber portion 36 and
includes an opening 38 disposed at the proximal end 31 of the first
outer-conductor structure 30. In some embodiments, the first
chamber portion 36 is configured to matingly engage, e.g.,
threadedly engage, with the retaining portion 23 of inner-conductor
pin 20, and the second chamber portion 35 is configured to receive
at least a portion of the tubular sleeve member 40 therein.
[0062] First outer-conductor structure 30 may be provided with an
end cap 37. End cap 37 generally includes a tapered portion 33,
which may terminate in a sharp tip 34 to allow for insertion into
tissue with minimal resistance. Tapered portion 33 may include
other shapes, such as, for example, a tip 34 that is rounded, flat,
square, hexagonal, or cylindroconical. End cap 37 may be formed of
a material having a high dielectric constant, and may be a trocar,
e.g., a zirconia ceramic. First outer-conductor structure 30 and
end cap 37 may be formed separately from each other, and coupled
together, e.g., with the aid of adhesive or solder. First
outer-conductor structure 30 and end cap 37 may form a single,
unitary structure. The shape and size of the first outer-conductor
structure 30 and the end cap 37 may be varied from the
configuration depicted in FIG. 5.
[0063] Second outer-conductor structure 60 defines a
longitudinally-extending internal bore or chamber 65 that extends
from the proximal end 61 to the distal end 62 of the second
outer-conductor structure 60. Chamber 65 is configured to receive
at least a portion of the tubular sleeve member 40 therein.
[0064] Junction structure 50 defines a longitudinally-extending
internal bore or chamber 55 therein and generally includes a distal
end 52 adapted for connection to the first outer-conductor
structure 30 and a proximal end 51 adapted for connection to the
second outer-conductor structure 60. In some embodiments, the
junction structure 50 includes a distal end 52 provided with a
series of external threads configured to matingly engage with a
series of internal threads disposed at the proximal end 31 of the
first outer-conductor structure 30, and a proximal end 51 provided
with a series of external threads configured to matingly engage
with a series of internal threads disposed at the distal end 62 of
the second outer-conductor structure 60. The shape and size of the
junction structure 50 may be varied from the configuration depicted
in FIG. 5.
[0065] FIGS. 6 through 13 show a sequentially-illustrated, assembly
of components forming the needle assembly 110 in accordance with
the present disclosure. FIG. 6 shows the inner-conductor pin 20. As
described above, inner-conductor pin 20 may be formed of any
suitable electrically-conductive material (e.g., metal such as
stainless steel, aluminum, titanium, copper, etc.) of any suitable
length. The shape and size of the inner-conductor pin 20 may be
varied from the configuration depicted in FIG. 6.
[0066] As cooperatively shown in FIGS. 6 and 7, inner-conductor pin
20 includes a distal end 22 including a retaining portion 23 that
is configured to be connectable, e.g., electrically and
mechanically, to the first outer-conductor structure 30. In some
embodiments, the retaining portion 23 is provided with a series of
external threads configured to matingly engage with a series of
internal threads disposed within the first chamber portion 36 of
the first outer-conductor structure 30. Alternatively, mechanical
fasteners, grooves, flanges, adhesives, and welding processes,
e.g., laser welding, or other suitable joining method may be used
to attach (or clip, connect, couple, fasten, secure, etc.) the
inner-conductor pin 20 to the first outer-conductor structure 30.
As shown in FIG. 7, a longitudinal axis "A"-A" is defined by the
inner-conductor pin 20.
[0067] As cooperatively shown in FIGS. 8 through 10, tubular sleeve
member 40 is configured to be receivable within second chamber
portion 35 of the first outer-conductor structure 30, chamber 55 of
the junction structure 50 and chamber 60 of the second
outer-conductor structure 60. FIG. 8 shows the tubular sleeve
member 40 joined together with the inner-conductor pin 20 and the
first outer-conductor structure 30 such that the tubular sleeve
member 40 is coaxially-disposed about the length of the inner
conductor 20 proximal to the retaining portion 23 and disposed at
least in part within the second chamber portion 35 of the first
outer-conductor structure 30. In an embodiment, the tubular sleeve
member 40 is positioned around the inner-conductor pin 20 after the
retaining portion 23 is coupled to the end cap 37, e.g., as shown
in FIG. 8. Tubular sleeve member 40 may, alternatively, be
positioned, formed, adhered or otherwise disposed around at least a
portion of the inner-conductor pin 20 prior to the introduction of
the inner-conductor pin 20 into the second chamber portion 35 of
the first outer-conductor structure 30.
[0068] FIG. 9 shows the portion of the needle assembly of FIG. 8
shown with junction structure 50 disposed around a portion of the
tubular sleeve member 40 and coupled to the first outer-conductor
structure 30. Junction structure 50 may be coupled to the first
outer-conductor structure 30 by any suitable manner of connection.
In the embodiment shown in FIG. 9, junction structure 50 includes a
distal end 52 provided with a series of external threads configured
to matingly engage with a series of internal threads disposed at
the proximal end 31 of the first outer-conductor structure 30. The
junction structure 50 and the first outer-conductor structure 30
(as well as other components described herein) may be assembled
together with the aid of alignment pins, snap-like interfaces,
tongue and groove interfaces, locking tabs, adhesive ports, etc.,
utilized either alone or in combination for assembly purposes.
[0069] FIG. 10 shows the portion of the needle assembly of FIG. 9
shown with second outer-conductor structure 60 disposed around a
portion of the tubular sleeve member 40 and coupled to the proximal
end 51 of the junction structure 50. In the embodiment shown in
FIG. 10, second outer-conductor structure 60 includes a distal end
62 provided with a series of internal threads configured to
matingly engage with a series of external threads disposed at the
proximal end 51 of the junction structure 50.
[0070] FIG. 11 shows the portion of the needle assembly of FIG. 10
shown with rectifier element 58 disposed above rectifier-receiving
recess 56 in the junction structure 50. Rectifier element 58
includes a first lead wire or pin 59a (also referred to herein as a
"terminal") and a second lead wire or pin 59b. Rectifier-receiving
recess 56 may be configured to receive the rectifier element 58
such that the first pin 59a and the second pin 59b are
substantially aligned with the longitudinal axis "A"-A" defined by
the inner-conductor pin 20.
[0071] FIG. 12 shows the portion of the needle assembly of FIG. 11
shown with the rectifier element 58 disposed in the
rectifier-receiving recess 56. First pin 59a is electrically
coupled to the first outer-conductor structure 30 by any suitable
manner of electrical connection, e.g., soldering, welding, or laser
welding. Second pin 59b is electrically coupled to the second
outer-conductor 60 by any suitable manner of electrical
connection.
[0072] FIG. 13 shows the portion of the needle assembly of FIG. 12
shown with an outer jacket 90 disposed around the first
outer-conductor structure 30, the second outer-conductor structure
60, and the junction structure 50. Outer jacket 90 may be formed of
any suitable material, such as, for example, polymeric or ceramic
materials. The outer jacket 90 may be applied by any suitable
method, such as, for example, heat-shrinkage, extrusion, molding,
coating, spraying, dipping, powder coating, baking and/or film
deposition, or other suitable process.
[0073] In an embodiment, as best shown in FIG. 14, which shows the
cross section of the needle assembly portion of FIG. 13, outer
jacket 90 covers the rectifier element 58. In alternative
embodiments, the outer jacket 90 may include an opening (not shown)
configured to expose the rectifier element 58 and/or the junction
structure 50, or portion thereof.
[0074] The position of the junction structure 50 and rectifier
element 58, e.g., in relation to the tip 34, is one factor in
determining the operational frequency of the microwave
field-detecting needle assembly 100 in a given material, e.g.,
tissue. To obtain a microwave field-detecting needle assembly
having a desired frequency, the junction structure 50 may be
positioned at a location of high voltage along the expected
standing wave that couples onto the probe, such as illustratively
shown in FIG. 15. During a procedure, e.g., an ablation procedure,
fields 1501, 1502 couple onto the microwave field-detecting needle
assembly 100 from the energy supplied by an energy-delivery device
(e.g., 12 shown in FIG. 18), e.g., a microwave ablation probe.
[0075] FIGS. 16 and 17 show a needle assembly (shown generally as
1610) according to an embodiment of the present disclosure that is
adapted to enable multi-frequency operation and/or multiple
wavelength operation. Needle assembly 1610 is similar to the needle
assembly 110 shown in FIGS. 1, 2 and 5, except for the
configuration of the junction structure 1650, the first
outer-conductor structure 1630 and the second outer-conductor
structure 1660, and the plurality of rectifiers 1658 disposed in
the plurality of recesses 1656.
[0076] Needle assembly 1610 includes a junction structure 1650
configured to separate a first outer-conductor structure 1630 and a
second outer-conductor structure 1660 in a diagonal fashion. First
outer-conductor structure 1630 and the second outer-conductor
structure 1660 may be formed of any suitable
electrically-conductive material, e.g., metal such as stainless
steel, aluminum, titanium, copper, or the like. In some
embodiments, the first outer-conductor structure 1630 is
constructed from stainless steel, and may be coated in a high
electrical conductivity, corrosion-resistant metal, e.g., silver,
or the like.
[0077] As best shown in FIG. 16, the junction structure 1650
includes a plurality of recesses 1656 defined therein, wherein each
recess 1656 is defined in a different outer-peripheral portion of
the junction structure 1650 and configured to receive a rectifier
1658 therein. Rectifier 1658 is similar to the rectifier 58 shown
in FIG. 2 and further description thereof is omitted in the
interests of brevity. Each rectifier 1658 may be configured to
operate efficiently at separate frequencies allowing for probe use
at multiple frequencies.
[0078] FIG. 18 shows an electrosurgical system 1800 according to an
embodiment of the present disclosure that includes an energy
applicator or probe 12 operably coupled to an electrosurgical power
generating source 26. In some embodiments, the probe 12 may be
coupled in fluid communication with a coolant supply system (not
shown).
[0079] Electrosurgical system 1800 (also referred to herein as a
"microwave ablation control system") generally includes one or more
microwave field-detecting needle assemblies 100 and a control unit
24 in operable communication with the one or more microwave
field-detecting needle assemblies 100. Control unit 24 and the one
or more microwave field-detecting needle assemblies 100 may utilize
wired communication and/or wireless communication. Control unit 24
is similar to the control unit 28 shown in FIG. 4 and further
description thereof is omitted in the interests of brevity.
Electrosurgical system 1800 according to various embodiments may
include a feedback loop 18 suitable for use in controlling an
energy applicator or probe 12 based on one or more electrical
signals transmitted by one or more microwave field-detecting needle
assemblies 100. Feedback loop 18 may utilize a cable connection
and/or a wireless connection, e.g., a radiofrequency or infrared
link.
[0080] In some embodiments, the microwave ablation control system
1800 may adjust the ablation field radiating about at least a
portion of the energy applicator 12 into tissue by adjusting one or
more operating parameters associated with the electrosurgical power
generating source 26 based on one or more electrical signals
transmitted by one or more microwave field-detecting needle
assemblies 100. In the embodiment illustrated in FIG. 18, the
plurality of microwave field-detecting needle assemblies 100 in
operable communication with the control unit 24 are operable
coupled via the feedback loop 18 to the electrosurgical power
generating source 26. Examples of operating parameters associated
with the electrosurgical power generating source 26 include
temperature, impedance, power, current, voltage, mode of operation,
and duration of application of electromagnetic energy.
[0081] It is to be understood that, although one energy applicator
12 and three microwave field-detecting needle assemblies 100 are
shown in FIG. 18, electrosurgical system embodiments may utilize
single or multiple energy applicators (or applicator arrays) and
one or more microwave field-detecting needle assemblies. The single
or multiple energy applicators and the one or more microwave
field-detecting needle assemblies may be arranged in any suitable
configuration.
[0082] Electrosurgical power generating source 26 may be any
generator suitable for use with electrosurgical devices, and may be
configured to provide various frequencies of electromagnetic
energy. In some embodiments, the electrosurgical power generating
source 26 is configured to provide microwave energy at an
operational frequency from about 300 MHz to about 10 GHz. In other
embodiments, the electrosurgical power generating source 26 is
configured to provide electrosurgical energy at an operational
frequency from about 400 KHz to about 500 KHz.
[0083] In some embodiments, the electrosurgical power generating
source 26 is configured or set to a predetermined setting. For
example, electrosurgical power generating source 26 may be set to a
predetermined temperature, such as a temperature that may be used
for the treatment of pain (e.g., about 42.degree. C. or about
80.degree. C.), a predetermined waveform, a predetermined duty
cycle, a predetermined time period or duration of activation,
etc.
[0084] Electrosurgical power generating source 26 may include a
user interface 25 (FIG. 19) in operable communication with a
processor unit 82 (FIG. 19). Processor unit 82, which is described
in more detail with respect to FIG. 19, may be any type of
computing device, computational circuit, or any type of processor
or processing circuit capable of executing a series of instructions
that are stored in a memory. In an embodiment, a physician may
input via the user interface 25 a selected power output, and the
microwave ablation control system 1800 controls the probe 12 to
automatically adjust the ablation volume by changing the operating
frequency of the probe 12, e.g., based on at least one electrical
signal transmitted by the one or more microwave field-detecting
needle assemblies 100.
[0085] In an embodiment, a physician may input via the user
interface 25 a selected power output, and the microwave ablation
control system 1800 controls the ablation field radiating about at
least a portion of the energy applicator 12 into tissue based on
one or more electrical signals transmitted by one or more microwave
field-detecting needle assemblies 100, e.g., by rotation of a
energy applicator with a directional radiation pattern to avoid
ablating sensitive structures, such as large vessels, healthy
organs or vital membrane barriers and/or by controlling the
electrosurgical power generating source 26 operatively associated
with an energy applicator 12.
[0086] During microwave ablation using the microwave ablation
control system 1800, one or more microwave field-detecting needle
assemblies 100 may be inserted into tissue "T" and/or placed
adjacent a sensitive structure "S", and/or one or more microwave
field-detecting needle assemblies 100 may be inserted into the
abdominal wall "W" and/or into the abdominal cavity "C". Probe 12
is inserted into tissue "T" and/or placed adjacent to a lesion "L".
Ultrasound or computed tomography (CT) guidance may be used to
accurately guide the probe 12 into the area of tissue to be
treated. Probe 12 and one or more microwave field-detecting needle
assemblies 100 may be placed percutaneously or surgically, e.g.,
using conventional surgical techniques by surgical staff. After the
one or more microwave field-detecting needle assemblies 100 and the
probe 12 are positioned, microwave energy is supplied to the probe
12.
[0087] A clinician may pre-determine the length of time that
microwave energy is to be applied. Application duration may depend
on many factors such as tumor size and location and whether the
tumor was a secondary or primary cancer. The duration of microwave
energy application using the probe 12 may depend on the progress of
the heat distribution within the tissue area that is to be
destroyed and/or the surrounding tissue. Treatment of certain
tumors may involve probe repositioning during the ablation
procedure, such as where the tumor is larger than the probe or has
a shape that does not correspond with available probe geometry or
radiation pattern.
[0088] FIG. 19 is a block diagram showing one embodiment of the
electrosurgical power generating source 26 of FIG. 18. In an
embodiment, the generator module 86 is configured to provide energy
of about 915 MHz. Generator module 86 may additionally, or
alternatively, be configured to provide energy of about 2450 MHz
(2.45 GHz). The present disclosure contemplates embodiments wherein
the generator module 86 is configured to generate a frequency other
than about 915 MHz or about 2450 MHz, and embodiments wherein the
generator module 86 is configured to generate variable frequency
energy. Electrosurgical power generating source 26 includes a
processor 82 that is operably coupled to the user interface 25.
Processor 82 may include any type of computing device,
computational circuit, or any type of processor or processing
circuit capable of executing a series of instructions that are
stored in a memory, e.g., storage device 88 or external device
91.
[0089] In some embodiments, storage device 88 is operably coupled
to the processor 82, and may include random-access memory (RAM),
read-only memory (ROM), and/or non-volatile memory (NV-RAM, Flash,
and disc-based storage). Storage device 88 may include a set of
program instructions executable on the processor 82 for executing a
method for displaying and controlling ablation patterns in
accordance with the present disclosure. Electrosurgical power
generating source 26 may include a data interface 90 that is
configured to provide a communications link to an external device
91. In some embodiments, the data interface 90 may be any of a USB
interface, a memory card slot (e.g., SD slot), and/or a network
interface (e.g., 100BaseT Ethernet interface or an 802.11 "Wi-Fi"
interface.) External device 91 may be any of a USB device (e.g., a
memory stick), a memory card (e.g., an SD card), and/or a
network-connected device (e.g., computer or server).
[0090] Electrosurgical power generating source 26 may also include
a database 84 that is configured to store and retrieve energy
applicator data, e.g., parameters associated with one or energy
applicators (e.g., 12 shown in FIGS. 18 and 19). Parameters stored
in the database 84 in connection with an energy applicator, or
energy applicator array, may include, but are not limited to,
energy applicator (or applicator array) identifier, energy
applicator (or applicator array) dimensions, a frequency, an
ablation length, an ablation diameter, a temporal coefficient, a
shape metric, and/or a frequency metric. In an embodiment, ablation
pattern topology may be included in the database 84, e.g., a
wireframe model of an applicator array and/or an ablation pattern
associated therewith and/or an arrangement of microwave
field-detecting needle assemblies for use in connection with one or
more energy applicators.
[0091] Database 84 may also be maintained at least in part by data
provided by the external device 91 via the data interface 90. For
example without limitation, data associated with energy applicator
12 may be uploaded from an external device 91 to the database 84
via the data interface 90. Energy applicator data may additionally,
or alternatively, be manipulated, e.g., added, modified, or
deleted, in accordance with data and/or instructions stored on the
external device 91. In an embodiment, the set of energy applicator
data represented in the database 84 is automatically synchronized
with corresponding data contained in the external device 91 in
response to the external device 91 being coupled (e.g., physical
coupling and/or logical coupling) to the data interface 90.
[0092] Processor 82 according to various embodiments is programmed
to enable a user, via the user interface 25 and/or a display device
(not shown), to view at least one ablation pattern and/or other
data corresponding to an energy applicator or an applicator array.
For example, a physician may determine that a substantially
spherical ablation pattern is necessary. The physician may activate
a "select ablation shape" mode of operation for electrosurgical
power generating source 26, preview an energy applicator array by
reviewing graphically and textually presented data, optionally, or
alternatively, manipulate a graphic image by, for example, rotating
the image, and select an energy applicator or an applicator array,
based upon displayed parameters. The selected energy applicator(s)
may then be electrically coupled to the electrosurgical power
generating source 26 for use therewith.
[0093] Electrosurgical power generating source 26 may include an
actuator 87. Actuator 87 may be any suitable actuator, e.g., a
footswitch, a handswitch, an orally-activated switch (e.g., a
bite-activated switch and/or a breath-actuated switch), and the
like. Actuator 87 may be operably coupled to the processor 82 by a
cable connection (e.g., 83 shown in FIG. 18) or a wireless
connection, e.g., a radiofrequency or infrared link.
[0094] In an embodiment, a physician may input via the user
interface 25 an applicator array parameter to cause the
electrosurgical power generating source 26 to present one or more
electromagnetic energy delivery devices corresponding thereto
and/or one or more microwave field-detecting needle assemblies for
use therewith. For example, a physician may require a 3.0
cm.times.3.0 cm.times.3.0 cm ablation pattern, and provide an input
corresponding thereto. In response, the electrosurgical power
generating source 26 may preview a corresponding subset of
available electromagnetic energy delivery devices that match or
correlate to the inputted parameter.
[0095] In an embodiment, a physician may input via the user
interface 25 a selected power output, and the electrosurgical
system 1800 controls the energy applicator 12 to adjust the
ablation field radiating about at least a portion of the energy
applicator 12 into tissue based on at least one electrical signal
transmitted by the one or more microwave field-detecting needle
assemblies.
[0096] Hereinafter, a method of manufacturing a needle assembly in
accordance with the present disclosure is described with reference
to FIG. 20, a method of manufacturing a microwave field-detecting
needle assembly in accordance with the present disclosure is
described with reference to FIG. 21, and a method of adjusting an
ablation field radiating into tissue is described with reference to
FIG. 22. It is to be understood that the steps of the methods
provided herein may be performed in combination and in a different
order than presented herein without departing from the scope of the
disclosure.
[0097] FIG. 20 is a flowchart illustrating a method of
manufacturing a needle assembly according to an embodiment of the
present disclosure. In step 2010, an inner-conductor pin 20 is
provided. A retaining portion 23 is disposed at a distal end 22 of
the inner-conductor pin 20.
[0098] In step 2020, a first outer-conductor structure 30 is joined
to the retaining portion 23.
[0099] In step 2030, a tubular sleeve member 40 is positioned
overlying a length of the inner-conductor pin 20 proximal to the
retaining portion 23. The tubular sleeve member 40 includes a
longitudinally-extending internal chamber 45 configured to receive
at least a portion of the inner-conductor pin 20 therein.
[0100] In step 2040, a junction structure 50 is joined to the
proximal end 31 of the first outer-conductor structure 30, whereby
the junction structure 50 is disposed around a portion of the
tubular sleeve member 40. The junction structure 50 includes a
recess 56 defined therein. The distal end 52 of the junction member
50 may be provided with a series of external threads configured to
matingly engage with a series of internal threads disposed at the
proximal end 31 of the first outer-conductor structure 30.
[0101] In step 2050, a second outer-conductor structure 60 is
joined to the proximal end 51 of the junction structure 50. The
proximal end 51 of the junction member 50 may be provided with a
series of external threads configured to matingly engage with a
series of internal threads disposed at the distal end 62 of the
second outer-conductor structure 60.
[0102] In step 2060, a rectifier element 58 is positioned into the
recess 56. In some embodiments, the rectifier element 58 includes a
first terminal 59a and a second terminal 59b. In such cases, the
first terminal 59a may be electrically coupled to the first
outer-conductor structure 30 and the second terminal 59b may be
electrically coupled to the second outer-conductor structure 60,
e.g., by solder or other suitable electrical connection.
[0103] FIG. 21 is a flowchart illustrating a method of
manufacturing a microwave field-detecting needle assembly according
to an embodiment of the present disclosure. In step 2110, a handle
assembly 170 is provided. An electric circuit 300 is disposed
within the handle assembly 170.
[0104] In step 2120, a needle assembly 110 is provided. The needle
assembly 110 includes a first outer-conductor structure 30 coupled
to an inner-conductor pin 20, a junction structure 50 disposed
between the first outer-conductor structure 30 and a second
outer-conductor structure 60, and a rectifier element 58 disposed
in a recess 56 defined in the junction structure 50. A first
terminal 59a of the rectifier element 58 is electrically coupled to
the first outer-conductor structure 30, and a second terminal 59b
is electrically coupled to the second outer-conductor structure
60.
[0105] In step 2130, the inner-conductor pin 20 and the second
outer-conductor structure 60 are electrically coupled to an
electric circuit 300 disposed within the handle assembly 170.
[0106] FIG. 22 is a flowchart illustrating a method of adjusting an
ablation field radiating into tissue according to an embodiment of
the present disclosure. In step 2210, an energy applicator 12 is
provided. In step 2220, one or more microwave field-detecting
needle assemblies 100 are provided. Each microwave field-detecting
needle assembly 100 includes one or more rectifier elements 58
capable of detecting microwave field intensity via
rectification.
[0107] In step 2230, the energy applicator 12 and the one or more
microwave field-detecting needle assemblies 100 are positioned in
tissue. The energy applicator 12 may be inserted directly into
tissue, inserted through a lumen, e.g., a vein, needle, endoscope
or catheter, placed into the body during surgery by a clinician, or
positioned in the body by other suitable methods known in the art.
The energy applicator 12 may be configured to operate with a
directional radiation pattern. The one or more microwave
field-detecting needle assemblies 100 may be positioned in
material, e.g., tissue, by any suitable method and arranged in any
configuration (e.g., configuration shown in FIG. 18).
[0108] In step 2240, energy is transmitted from an energy source 26
through the energy applicator 12 to generate an ablation field
radiating about at least a portion of the energy applicator 12 into
tissue. The energy source 26 may be any suitable electrosurgical
generator for generating an output signal. In some embodiments, the
energy source 26 is a microwave energy source, and may be
configured to provide microwave energy at an operational frequency
from about 300 MHz to about 10 GHz.
[0109] In step 2250, the ablation field radiating about at least
the portion of the energy applicator 12 into tissue is adjusted
based on at least one electrical signal transmitted by the one or
more microwave field-detecting needle assemblies 100. In some
embodiments, adjusting the ablation field radiating about at least
the portion of the energy applicator 12 into tissue, in step 2250,
may include adjusting at least one operating parameter associated
with the energy source 26 based on the at least one electrical
signal transmitted by the one or more microwave field-detecting
needle assemblies 100. Examples of operating parameters associated
with the energy source 26 include temperature, impedance, power,
current, voltage, mode of operation, and duration of application of
electromagnetic energy.
[0110] According to various embodiments of the present disclosure,
the above-described microwave field-detecting needle assembly
enables physicians to detect field intensity in proximity to an
energy-delivery device. The presently-disclosed microwave
field-detecting needle assembly embodiments may allow the physician
to determine if a microwave field is strong enough for the intended
purpose or to achieve a desired surgical outcome.
[0111] The presently-disclosed microwave field-detecting needle
assembly embodiments may be suitable for utilization in minimally
invasive procedures, e.g., endoscopic and laparoscopic surgical
procedures. The above-described microwave field-detecting needle
assembly embodiments may be suitable for utilization in open
surgical applications.
[0112] Various embodiments of the presently-disclosed microwave
field-detecting needle assembly embodiments may allow the physician
to determine when a microwave ablation probe is inserted to a
proper depth within tissue, e.g., to reach the location of the
ablation site and/or to avoid unintended field exposure. Various
embodiments of the presently-disclosed microwave field-detecting
needle assembly are adapted to be coupled in communication with a
stand-alone control unit.
[0113] Electrosurgical systems including one or more microwave
field-detecting needle assemblies according to embodiments of the
present disclosure may protect sensitive structures, ensure
expected field pattern and/or protect the abdominal wall from stray
microwave fields.
[0114] The above-described microwave field-detecting needle
assemblies may be used to detect microwave field intensity emitted
by an energy applicator, and an electrical signal transmitted from
the presently-disclosed microwave field-detecting needle assemblies
may be used to control the positioning of an electrosurgical device
(e.g., rotation of a energy applicator with a directional radiation
pattern to avoid ablating sensitive structures, such as large
vessels, healthy organs or vital membrane barriers), and/or control
an electrosurgical power generating source operatively associated
with an energy applicator.
[0115] Although embodiments have been described in detail with
reference to the accompanying drawings for the purpose of
illustration and description, it is to be understood that the
inventive processes and apparatus are not to be construed as
limited thereby. It will be apparent to those of ordinary skill in
the art that various modifications to the foregoing embodiments may
be made without departing from the scope of the disclosure.
* * * * *