U.S. patent application number 13/356433 was filed with the patent office on 2013-01-31 for radiofrequency catheter.
This patent application is currently assigned to VERTECH, INC.. The applicant listed for this patent is Andres Betts, Shiva Sharareh. Invention is credited to Andres Betts, Shiva Sharareh.
Application Number | 20130030427 13/356433 |
Document ID | / |
Family ID | 40789479 |
Filed Date | 2013-01-31 |
United States Patent
Application |
20130030427 |
Kind Code |
A1 |
Betts; Andres ; et
al. |
January 31, 2013 |
Radiofrequency Catheter
Abstract
An integrated catheter shaft with a guidewire and a radio
frequency wire is used in a catheter to deliver radio frequency
energy to a treatment site. The small entry wound and the long
integrated catheter shaft allows a user to thread the shaft along a
tortuous route along a spinal canal to reach a treatment site while
causing a minimal amount of trauma to the patient.
Inventors: |
Betts; Andres; (San
Clemente, CA) ; Sharareh; Shiva; (Laguna Niguel,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Betts; Andres
Sharareh; Shiva |
San Clemente
Laguna Niguel |
CA
CA |
US
US |
|
|
Assignee: |
VERTECH, INC.
San Clemente
CA
|
Family ID: |
40789479 |
Appl. No.: |
13/356433 |
Filed: |
January 23, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
12359204 |
Jan 23, 2009 |
8103356 |
|
|
13356433 |
|
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|
11752210 |
May 22, 2007 |
8075556 |
|
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12359204 |
|
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|
60802685 |
May 23, 2006 |
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Current U.S.
Class: |
606/33 |
Current CPC
Class: |
A61B 2018/00791
20130101; A61B 2018/1405 20130101; A61B 2018/00196 20130101; A61B
2018/1475 20130101; A61B 2218/002 20130101; A61B 18/1492 20130101;
A61B 2018/0044 20130101; A61B 2018/00434 20130101; A61B 2017/22038
20130101; A61B 2018/00083 20130101 |
Class at
Publication: |
606/33 |
International
Class: |
A61B 18/18 20060101
A61B018/18 |
Claims
1. A guideable catheter for delivering radiofrequency energy to a
treatment site; comprising: a flexible shaft having a proximal end
and a distal end, wherein the shaft has an outer diameter of at
most 2 mm; a guidewire extending along a first length of the shaft;
and concurrently a radio frequency wire extending along a second
length of the shaft.
2. The catheter of claim 1, wherein the outer diameter of the shaft
is at most 1.5 mm.
3. The catheter of claim 1, wherein the outer diameter of the shaft
is at most 1 mm.
4. The catheter of claim 1, further comprising an angulation
attached to a distal end of the guidewire.
5. The catheter of claim 1, further comprising a radio frequency
insulator at least partially encapsulating the radio frequency
wire.
6. The catheter of claim 5, wherein the radio frequency insulator
encapsulates all but a distal end of the radio frequency wire.
7. The catheter of claim 1, further comprising a radio frequency
adapter connected to a proximal end of the radio frequency
wire.
8. The catheter of claim 7, wherein the adapter is selected from
the group consisting of a radal adapter and a tuohy-borst
adapter.
9. The catheter of claim 1, further comprising a fluid passageway
within the shaft extending along a third length of the shaft to an
injection port at the distal end of the shaft.
10. The catheter of claim 9, wherein the fluid passageway extends
to a second injection port at the distal end of the shaft.
11. The catheter of claim 1, further comprising a temperature
sensor extending along a fourth length of the shaft.
12. The catheter of claim 1, wherein the guidewire is a temperature
sensor.
13. The catheter of claim 1, wherein the distal end of the shaft is
blunt.
14. The catheter of claim 1, wherein a cross-section of the distal
end of the shaft is an angled polygon.
15. The catheter of claim 1, wherein a cross-section of the distal
end of the shaft is an ellipse.
16. The catheter of claim 1, wherein the catheter comprises
stainless steel.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of U.S. patent
application Ser. No. 12/359,204 filed Jan. 23, 2009 which is a
continuation-in-part of U.S. patent application Ser. No.
11/752,210, filed May 22, 2007, now issued U.S. Pat. No. 8,075,556,
which claims priority to U.S. Provisional Application No.
60/802,685, filed on May 23, 2006, which are all hereby
incorporated by reference in their entirety.
FIELD OF THE INVENTION
[0002] The field of the invention is pain treatment medical
devices.
BACKGROUND OF THE INVENTION
[0003] Lower back pain is a common problem for many patients across
the world. Frequently, lower back pain can not be fully treated,
and can only be managed through pain therapy treatments such as
medication or massage therapy. In more extreme situations, doctors
can provide pain therapy by applying radiofrequency energy to the
spine. U.S. Pat. No. 5,433,739 to Sluijter teaches a radiofrequency
device that can be inserted into a spinal structure to heat and
kill nerve structures and deliver pain relief. Unfortunately, such
a technique can be indiscriminate in its destruction and can
greatly harm the patient even if used by a skilled surgeon.
Sluijter '739 and all other extrinsic materials discussed herein
are incorporated by reference in their entirety. Where a definition
or use of a term in an incorporated reference is inconsistent or
contrary to the definition of that term provided herein, the
definition of that term provided herein applies and the definition
of that term in the reference does not apply.
[0004] A further study, published in "Radiofrequency ablation in
the management of spinal pain" (C.sup.2I.sup.2 Volume IV, Issue 1,
pub. April 2006), has demonstrated that pulsed radiofrequency
energy can be used to minimize the damage done to the spinal column
and still be effective at treating pain. However, the current
apparatus and method for delivering such radiofrequency energy uses
a short, straight SMK disposable catheter which requires an
operation to open a large wound around the area of the treatment
site for the catheter. Not only can the patient become infected
during such an operation, but some intervertebral discs may not
have adequate space between them for the catheter to maneuver.
[0005] U.S. Pat. No. 6,602,242 to Fung teaches an electrode
catheter that can be guided to send radiofrequency energy to a
spinal nerve treatment site, however, such a large catheter also
requires the medical professional to open a large wound in the
patient's back for surgery before the catheter can be used. A
larger wound exposes the patient to more surgical complications and
extends the recovery time of patients from recovering from the
ablation process.
[0006] Thus, there is still a need for improved systems and methods
of delivering pulsed radiofrequency energy.
SUMMARY OF THE INVENTION
[0007] The present invention provides apparatus, systems and
methods in which an integrated catheter with both a guidewire and a
radio frequency wire percutaneously delivers radio frequency energy
to a treatment site. The treatment site is generally located along
the spinal of the patient, for example an epidural space in the
lumbar region. Contemplated patients include any animal with a
spine, for example canines, monkeys, or cats, but are preferably
human beings.
[0008] The catheter preferably has a flexible shaft that is small
enough to be used on a patient percutaneously. The shaft preferably
has an outer diameter of at most than 3 mm, but is more preferably
at most 2 mm, 1.5 mm, 1.2 mm, or even at most 1 mm in diameter. In
an exemplary embodiment, the outer diameter of the shaft is at most
0.7 mm. As used herein, an "outer diameter" of the shaft is the
distance between opposing exterior surfaces of the shaft. While the
term "diameter" commonly refers to a circular cross-section, the
cross-section of the catheter could be other shapes, for example
ovals, squares, and triangles. Unless a contrary intent is apparent
from the context, all ranges recited herein are inclusive of their
endpoints, and open-ended ranges should be interpreted to include
only commercially practical values.
[0009] As used herein, a "percutaneous" medical procedure is one
where access to the inner organs of the patient is via a
needle-sized puncture in the skin rather than by first opening a
hole in the patient before inserting the needle. Generally, a
needle or a cannula is first inserted into the epidural space, and
the shaft of the catheter is then inserted into the needle and is
then guided towards the treatment site. Needles could have an outer
diameter as large as 6 mm, but are preferably at most 5 mm, 4.5 mm,
4 mm, 3.5 mm, or even at most 3 mm. A smaller needle reduces the
size of the wound and minimizes the amount of pain and trauma
caused to the patient during the procedure.
[0010] The shaft has a proximal end that is handled by a medical
professional or a machine and a distal end that enters the patient
and is guided towards the treatment site. The distal end could be a
sharp tip, but is preferably blunt to reduce any trauma to the
tissue surrounding the treatment site. A portion of the distal end
is preferably made out of a material that transmits radio frequency
energy and has a cross-section that forms an angled polygon. As
used herein, an "angled polygon" is any polygon that is not an
ellipse. An exemplary distal end is made of stainless steel and has
a cross-section in the form of a teardrop to help focus radio
frequency energy transmitted from the catheter to the treatment
site.
[0011] The shaft itself is flexible enough to be guided through a
tortuous path within the patient. A "tortuous path" is defined
herein as any non-linear path that generally has at least two bends
or turns. The shaft could be made of a flexible material, for
example rubber or other polymers, or could be made of a stiff
material that is segmented, for example stainless steel, to allow
the shaft to bend in between the segments. While the segmented
sections are preferably identical to one another and are evenly
spaced apart, segmented sections could be evenly or unevenly spaced
and could have segments of different dimensions without departing
from the scope of the present invention.
[0012] The flexible shaft preferably also has a guidewire that is
used to steer the catheter towards the treatment site. As used
herein, a "guidewire" is any flexible wire, preferably metallic,
that provides support to the structure of the shaft of the
catheter. The guidewire could be embedded in a wall of the
catheter, could be within a lumen of the shaft, or could compose
the wall of the shaft itself While the guidewire could extend along
the entire length of the shaft, the guidewire is preferably at
least 5, 10, or even 5 mm shorter than the length of the shaft,
stopping just short of the distal end of the catheter. In this
instance, and where other upper limits are not expressly stated,
the reader should infer a reasonable upper limit. In this instance,
for example, a commercially reasonable upper limit is about 30 mm.
The guidewire could be guided and controlled using an electronic
device connected to a proximal end of the catheter, but is
preferably guided manually by pulling, pushing, and turning the
proximal end of the catheter.
[0013] The tip of the distal end of the shaft preferably has an
angulation to help with the steering. As used herein, an
"angulation" is a stiff structure that rests at an angle from the
rest of the shaft. The angulation is preferably malleable to allow
a user to bend the tip of the distal end at a sharper or a gentler
angle, depending on the needs of the user. By twisting and/or
bending the angulation one way or another, a user could "aim" the
shaft towards a treatment site before pushing the shaft forward,
which helps guide the shaft along a tortuous path within the
patient's body towards a treatment site. In an exemplary
embodiment, the top of the distal end of the shaft has a larger
diameter than the main body of the shaft, but is at most 1.5, 1.3,
or even 1 mm in diameter.
[0014] The catheter also preferably has a radio frequency wire that
is used to send radio frequency energy along the length of the
shaft to the treatment site. It is contemplated that a user of the
catheter could also transmit electrical current to the treatment
site using the radio frequency wire. The radio frequency wire is
preferably shorter than the shaft, and could be used to deliver
radio frequency energy from any point of the catheter to any point
along the shaft. Preferably, the radio frequency wire transmits
radio frequency energy from the proximal end of the shaft to the
distal tip of the shaft. A radio frequency adapter, for example a
Radal.TM. adapter or a Tuohy-Borst.TM. adapter, could be used to
couple the proximal end of the radio frequency wire to a radio
frequency generator.
[0015] A radio frequency insulator preferably surrounds the radio
frequency wire to prevent radio frequency energy from escaping the
catheter shaft. Preferably, the radio frequency insulator
encapsulates all but one or two sections of the radio frequency
wire, although the radio frequency insulator could encapsulate the
wire in a variety of ways without departing from the scope of the
invention. The insulator could encapsulate just the wire, or could
be embedded in the wall of the shaft itself. In an exemplary
embodiment, the radio frequency insulator encapsulates all but the
distal end of the shaft, allowing radio frequency energy to be
transmitted only from the distal end of the shaft at a transmission
site.
[0016] The transmission site could be the end of the radio
frequency wire within the shaft, but is preferably the entire
distal end of the shaft. The distal end of the shaft could be made
of a material that easily transmits radio frequency energy, for
example copper or platinum, such that when the radio frequency wire
abuts the distal end of the shaft, the distal end of the shaft
emits radio frequency energy. The distal end could be generally
cylindrical in shape with a rounded end, which causes radio
frequency energy to radiate evenly in all directions. It is
contemplated, however, that radio frequency energy from the wire
could be "aimed" by shaping the transmission site to have a cross
section shaped like an angled polygon. As used herein, an "angled
polygon" is any polygon that is not a circle or an ellipse that has
at least one sharp angle. The transmission site could then be
twisted to "aim" an angled protrusion of the transmission site,
formed by the shape of the cross-section, towards the center of the
treatment site to increase efficacy. While the cross section of the
transmission site is preferably an angled polygon, the actual tip
of the shaft is preferably blunt to prevent cutting, scraping, or
otherwise causing unnecessary trauma to the treatment site.
[0017] The shaft also preferably has a temperature sensor that
sends temperature readings to the proximal end of the catheter. The
temperature sensor could detect a variety of temperatures along the
length of the shaft, including for example the distal end of the
shaft, the temperature of the patient at the treatment site, the
temperature of the patient at a non-treatment site, or a
combination thereof. In a preferred embodiment, the temperature
sensor and the guidewire are the same wire to save space.
[0018] The temperature sensor and the radio frequency wire are
preferably both attached to a common machine, so that the radio
frequency energy that is sent can be regulated depending on
temperature readings of the treatment site. For example, radio
frequency energy could be streamed or pulsed towards the treatment
site until a temperature has been reached, and then the radio
frequency energy could be turned down or completely turned off
until the temperature falls below a certain threshold. For example,
a user who wishes to regulate a temperature of the treatment site
to 40.degree. F. could set the radio frequency energy to deactivate
when the temperature is above 45.degree. F. or even 42.degree. F.,
and could set the radio frequency energy to reactivate when the
temperature is below 35.degree. F. or 38.degree. F. The threshold
temperatures could be set at any temperature without departing from
the scope of the invention.
[0019] The catheter could also be used to inject medication into
the treatment site by having a liquid passageway, for example a
lumen, which extends along a length of the shaft. Preferably, the
lumen has more than one injection ports at the distal end of the
shaft to help distribute the medication evenly in multiple
directions. The injection ports could be angled from one another,
or could be parallel from one another, or be arranged in any
variety of shapes without departing from the scope of the
invention. The medication that is delivered to the treatment site
could be any suitable liquid, for example a local anesthetic, a
pharmaceutical, stem cells, proteins, or any other biological or
genetically modified matter.
[0020] The catheter as described could easily be used to treat pain
along a spine of an animal, preferably around the lumbar region. As
used herein, "along the spine" means that a portion of the catheter
is within 5 mm of a vertebra of the patient. In one embodiment, for
example, a doctor could first insert a needle into an entry point
of a human patient. Contemplated entry points include an epidural
space, a paravertebral space, and a lumbar region, although the
needle could be inserted in other points without departing from the
scope of the current invention. The doctor could then thread the
distal end of the catheter through the needle into the epidural
space, and guide the tip of the catheter to a treatment site along
the spine, for example the dorsal root ganglion, the spinal root,
the spinal cord, or the epidural space itself. Preferably, the
treatment site is by or between two vertebrae of the patient's
spine. Preferably, the doctor steers the catheter shaft through a
tortuous path by manipulating the proximal end of the catheter
while following the shaft's movements through a fluoroscope. An
angulation of the distal end could improve the accuracy of the
procedure by helping the doctor steer the catheter through the
tortuous path and aim radiofrequency energy and/or medication being
delivered to the treatment site.
[0021] Once the distal end of the catheter shaft is guided to the
treatment site, the doctor could then easily inject medication,
extract tissue, send streams or pulses of radio frequency energy,
and/or detect the temperature of the treatment site without needing
to remove the catheter between tasks. The catheter itself could be
made from reusable material so as to be easily sterilized for
multiple uses, or could be made from cheaper, biodegradable
material so as to be easily disposed of after a single use. Any
suitable material for making catheters could be used without
departing from the scope of the invention
[0022] Various objects, features, aspects and advantages of the
inventive subject matter will become more apparent from the
following detailed description of preferred embodiments, along with
the accompanying drawings in which like numerals represent like
components.
FIGURES
[0023] FIG. 1 is a partially exploded, cross-sectional view of a
catheter apparatus constructed in accordance with the present
invention.
[0024] FIG. 2 is a cross-sectional view of the catheter apparatus
shown in FIG. 1 in a fully assembled state.
[0025] FIG. 3 is an enlargement of the encircled region 3-3 shown
in FIG. 2.
[0026] FIG. 4 is a cross-sectional area of the catheter shaft shown
in FIG. 3 taken along line 4-4.
[0027] FIGS. 5A and 5B show alternative embodiments of
cross-sectional areas of contemplated catheters.
[0028] FIG. 6 is a side cross-sectional view of the catheter
apparatus of FIG. 1 being used on a patient's lumbar area.
DETAILED DESCRIPTION OF THE DRAWING
[0029] Referring to the drawings to illustrated preferred
embodiments, but not for the purpose of limiting the invention,
FIG. 1 shows a partially assembled catheter apparatus 10
constructed in accordance with the present invention. The catheter
apparatus 10 generally includes a needle assembly 12 having an
elongate needle 13, a shaft assembly 19 having an elongate shaft
20, and a catheter hub 37. Needle 13 has an outer diameter of 4.5
mm, but could be larger or smaller depending on the needs of the
operation and the thickness of shaft 20. Preferably, needle 13 has
an outer diameter of at most 6 mm, and even more preferably at most
4 mm. Preferably, the outer diameter of shaft 20 and the inner
diameter of the needle 13 (i.e., the diameter of the lumen 16) are
sized relative to each other within a prescribed tolerance range to
permit slidable movement of shaft 20 through lumen 16, yet presents
a close enough fit to substantially inhibit fluid leakage
therebetween.
[0030] Needle 13 of needle assembly 12 has an open proximal end 14
which is defined within one end of an enlarged needle hub 15 of
needle assembly 12, where needle 13 is partially disposed within
needle hub 15. Needle hub 15 is configured to be easily graspable
to allow for the insertion of needle 13 into a desired entry point
in the patient, preferably the epidural space. Needle 13 further
includes a hollow lumen 16 and an open distal end 18. Hollow lumen
16 is generally shaped and sized to allow a catheter shaft of at
most 1.3 mm in diameter to slide in and out of hollow lumen 16
without abrasive shearing. Preferably, the interior of hollow lumen
16 is padded around the open distal end 18 to further prevent
sheering. The distal end 18 of needle 13 is itself defined by a
sharpened tip for penetrating a patient's tissue, although other
unsharpened tips could be used without departing from the scope of
the invention. A sharpened tip is preferred as it allows a user to
penetrate a spinal canal or an epidural space before guiding the
catheter shaft to the treatment site (not shown). Needle assembly
12 could be manipulated (i.e., distal end 18 of needle 13 could be
advanced through the patient's tissue to a desired treatment site
with the spinal canal) by manually grasping the needle hub 15
thereof. It is also contemplated that a mechanical manipulator
could be coupled to needle hub 15 to assist in manipulation of the
needle assembly in the correct location of the patient.
[0031] Catheter apparatus 10 of the present invention further
comprises a shaft assembly 19 which is cooperatively engageable to
needle assembly 12 in the manner shown in FIGS. 1 and 2. While
shaft assembly 19 is shown as being engageable to needle assembly
15, and preferably engages needle assembly 15 during use to prevent
the catheter shaft from moving during treatment, shaft assembly 19
could freely move without attaching itself to needle assembly 15
during use. Shaft assembly 19 comprises an elongate, flexible shaft
20 which is telescopically disposed within and selectively
advanceable through lumen 16 of needle 13. While shaft 20 is shown
as a single, flexible material, shaft 20 could be made of a series
of stiff segments coupled together on rotatable junctions to allow
shaft 20 to appear flexible as a whole. Preferably, shaft 20 is
made of stainless steel segments. Shaft 19 generally has an outer
diameter of about 1.2 mm except for the distal tip, where the outer
diameter widens to about 1.4 mm, but shaft 19 could have larger or
smaller dimensions without departing from the scope of the current
invention.
[0032] Shaft 20 includes a closed distal end 23 which is itself
defined by a blunt tip having a generally semi-spherical outer
surface. Preferably, distal end 23 has an angulation that could be
reshaped to allow for an angled distal tip. While the surface of
the distal tip is generally semi-spherical, the cross-section of
the tip could be angled in various ways. In addition to the distal
end 23, shaft 20 further comprises three lumens 24 that lead to
proximal end 26. While all hollow lumens 24 lead to the same
proximal end, hollow lumens 24 could be of different lengths and
could have multiple proximal ends along the length of the needle
assembly without departing from the scope of the invention.
Proximal end 26 of shaft 20 is defined within an enlarged catheter
hub 27 of shaft assembly 19 such that shaft 20 is partially
disposed within catheter hub 27.
[0033] As shown in FIG. 2, when shaft assembly 19 is connected to
needle apparatus 10, the length of shaft 20 exceeds the length of
needle 13 such that when shaft assembly 19 is operatively coupled
to the needle assembly 12 (i.e., the catheter hub 27 engages the
needle hub 15), distal portion 23 of shaft 20 will protrude well
beyond distal end 18 of needle 13. While the current embodiment
shows the catheter protruding only 10 mm past the end of the
needle, it is contemplated that the catheter could protrude at
least 20 mm, 40 mm, or even 80 mm beyond the end of the needle as
it threads through a tortuous path to the treatment site.
[0034] A close up of distal end 23 is shown in FIG. 3, which has
three lumens: fluid passageway 42 that leads to injection ports 25;
radio frequency wire 44, and temperature sensor wire 46 that all
terminate within angulation 47. Angulation 47 is preferably made
from a single stiff yet malleable material that conducts both
radiofrequency energy and electrical current, although the material
could be made of non-conductive materials without departing from
the scope of the invention. Preferably, angulation 47 is bendable
only along a single joint (not shown) so that the angulation could
be bent and/or twisted in various directions without collapsing or
deforming the lumens within, thereby preserving the overall
function of catheter 10. Since radio frequency wire 44 abuts
angulation 47, angulation 47 acts as a transmission site for any
radio frequency energy or electrical energy that is sent along the
radio frequency wire. A user could angle the angulation with
respect to the rest of the catheter shaft, helping to aim the
transmitted energy and also to steer the catheter shaft to the
treatment site.
[0035] Fluid passageway 42 leads to multiple injection ports 25,
better seen in cross-section FIG. 4 as three injection ports 25
that equally distribute medication in three directions,
approximately 120 degrees apart from one another. While the
injection ports are shown as three equally spaced injection ports
along a single cross-section, more or less injection ports could be
used at varying angles that could be distributed across the entire
length of distal end 23. The injection ports are preferably located
on the side wall of distal end 23, as opposed to the tip of the
distal end, in order to minimize the amount of tissue that may plug
up the injection port.
[0036] Radio frequency wire 44 is constructed from a flexible
material, preferably metal, that is capable of transmitting radio
frequency energy. Preferably, radio frequency wire 44 also
transmits electrical energy. Shaft 20 is encapsulated is covered or
encapsulated by an insulating layer 48 of material that insulates
against both electrical energy and radio frequency energy. Suitable
materials are disclosed in WO/1988/008610, which is incorporated
herein by reference in its entirety. As shown in FIG. 3, angulation
47 is not covered by insulating layer 48, which allows radio
frequency and/or electrical energy of being freely transmitted from
angulation 47. It is contemplated that other kinds of energy could
be sent through radio frequency wire 44, for example electrical
energy, ultrasound energy, acoustical energy, optical energy, and
optics acoustical energy.
[0037] Temperature sensor 46 is also constructed from a flexible
material that is capable of detecting temperature and changes in
temperature. Temperature sensor 46 is configured to detect the
temperature of angulation 47, but could also be threaded through a
hole in the angulation or in the wall of the catheter itself to
detect a temperature of the surrounding tissue. All suitable
temperature sensor materials could be used without departing from
the scope of the current invention. In the current embodiment,
temperature sensor 46 is made from a robust, flexible material that
provides form to the catheter so that it also acts as a guidewire
for shaft 20. It is contemplated that temperature sensor 46 could
be replaced by other sensors, for example an electrical sensor, an
ultrasound sensor, an acoustics sensor, an optics sensor, and an
optic acoustics sensor.
[0038] A radio frequency adapter 32 is cooperatively engageable to
shaft assembly 19, and could be connected to a radio frequency or
an electrical current generator, for example COSMAN.TM.,
STRIKER.TM., SMITH NEPTHER.TM., BALLARD.TM., and KIMBERLY CLARK.TM.
radio frequency generators. Contemplated radio frequency adapters
include radal adapters and tuohy-borst adapters. The radio
frequency adapter 32 generally comprises the radio frequency wire
44, which is capable of conveying or transmitting radio frequency
energy or electrical energy received from a generator (not shown).
Radio frequency wire 44 has a distal end 45 and an opposed proximal
end 36 which resides within an adapter hub 37 of the radio
frequency adapter 32. The adapter hub 37 is itself configured to be
operatively coupled to the radio frequency generator in a manner
which effectively facilitates the transmission of radio frequency
energy from the radio frequency generator into the radio frequency
wire 44, and finally into angulation 47. Preferably, the radio
frequency adapter 32 is configured to couple with both the radio
frequency wire 44, and the temperature sensor 46 so that a single
machine could automatically deliver bursts of radio frequency
energy based upon sensed temperature.
[0039] Radio frequency energy could be "aimed" at a treatment site
by shaping the angulation (or the radio frequency wire itself in
cases where the angulation does not transmit radio frequency
energy) as an angled polygon. FIGS. 5A and 5B show alternative
cross sections 50 and 55 with a square angled polygon and a
teardrop angled polygon. Cross section 50 has four injection ports
52 that evenly disperse medication in four opposing directions, and
has four angled projections 54 that focus radio frequency energy
towards the tip of the angled projection. A doctor who wishes to
transmit radio frequency energy in a square-shaped pattern could
use an angulation with a square-shaped cross-section. A preferred
cross-section is the teardrop angled polygon shown in cross-section
55. Teardrop angled polygon has two injection ports 56, but only
one angled projection 58. Radio frequency energy will be
concentrated at the tip of angled projection 58, and the doctor
could twist and turn the angled projection to focus the intensity
of the radio frequency towards a specific trouble spot. An
exemplary angulation tapers from the angled cross-section towards a
spherical shape near the distal end of the angulation, so as to
provide a blunt distal tip for the catheter.
[0040] Since distal portion 23 of shaft 20 could protrude from the
distal end 18 of needle 13, the blunt distal end 23 of the shaft 20
could be guided to a desired treatment region within or just
outside of the spinal canal of the patient. Such positioning or
placement may be effectuated without causing sheering damage to the
treatment region due to the absence of any sharpened point or tip
on the distal portion 23 of the shaft 20. The positioning of the
distal end 23 of the shaft 20 at the appropriate treatment site
treatment site could be facilitated by the selective manipulation
of the catheter hub 27 of the shaft assembly 19 manually or with
the assistance of a machine. Preferably, the catheter is guided to
the treatment site under the guidance of a fluoroscope or another
similar X-ray device.
[0041] In FIG. 6, catheter apparatus 10 is used to deliver
medication and radio frequency energy to dorsal nerve 38. Prior to
guiding the catheter shaft to the treatment site, the shaft could
first be pulled back into needle 13 of needle assembly 12 so that
the distal end 23 of shaft 20 does not protrude beyond the distal
end 18 of needle 13. Since distal end 23 does not protrude beyond
sharpened distal end 18, the user of the catheter apparatus 10 is
able to use the sharpened distal end 18 of the needle 13 to pierce
or penetrate the patient's tissue to an appropriate entry site,
preferably adjacent to the desired treatment site. After needle 13
has penetrated the patient's tissue, shaft 20 could be advanced
through lumen 24 of needle 13, and guided to the treatment site.
While FIG. 6 shows the catheter shaft being advanced only a few
millimeters to reach the treatment site, a skilled physician with a
longer shaft could thread the shaft up through the entire spinal
canal to hit a vertebra more than 40 mm from the entry point.
[0042] Again, imaging techniques, including x-ray imaging, could be
used to visually assist the user in properly placing or positioning
distal end 23 of shaft 20 at the desired treatment site 38 within
the patient's spinal canal. Once the distal end 23 of shaft 20 has
been properly positioned at the desired treatment region within the
spinal canal 38 of the patient, the user could then inject
medication, apply electronic current to the treatment site, and/or
could apply radio frequency energy to the treatment site. Upon the
completion of the treatment, the catheter apparatus 10 is simply
withdrawn from within the spinal canal 38 of the patient.
[0043] Advantageously, because the distal end 23 of the shaft 20
has a closed, blunt configuration, critical treatment areas within
the spinal canal 38 of the patient may be reached with
substantially reduced risk of permanently damaging the nerves to be
treated as could occur by any attempted placement of the sharpened
tip of a needle near such nerves. In this regard, sharpened distal
end 18 of needle 13 need not be placed in close proximity to the
treatment region within the spinal canal 38 of the patient due to
the capability of advancing the distal portion 23 of the shaft 20
substantially beyond distal end 18 through the use of shaft
assembly 19 of the present invention, especially with extra-long
catheter shafts with integrated guidewires. Additionally, since the
catheter shaft has the combined functionality of a guidewire, an
injection lumen, a radio frequency transmitter, an electrical
energy transmitter, and a temperature sensor, multiple wires do not
need to be threaded through the same lumen over and over again,
which reduces trauma to the patient and possible shearing within
the lumen. Thus, due to its structural and functional attributes,
the catheter apparatus 10 of the present invention is capable of
being used in critical treatment areas within the spinal canal 38
of a patient while minimizing trauma to the patient.
[0044] It should be apparent to those skilled in the art that many
more modifications besides those already described are possible
without departing from the inventive concepts herein. The inventive
subject matter, therefore, is not to be restricted except in the
spirit of the appended claims. Moreover, in interpreting both the
specification and the claims, all terms should be interpreted in
the broadest possible manner consistent with the context. In
particular, the terms "comprises" and "comprising" should be
interpreted as referring to elements, components, or steps in a
non-exclusive manner, indicating that the referenced elements,
components, or steps may be present, or utilized, or combined with
other elements, components, or steps that are not expressly
referenced. Where the specification claims refers to at least one
of something selected from the group consisting of A, B, C . . .
and N, the text should be interpreted as requiring only one element
from the group, not A plus N, or B plus N, etc.
* * * * *