U.S. patent application number 13/902654 was filed with the patent office on 2013-10-03 for sonic endovenous catheter.
This patent application is currently assigned to CoolTouch Incorporated. The applicant listed for this patent is CoolTouch Incorporated. Invention is credited to David J. Fullmer, David R. Hennings, Craig Lindsay, Eric B. Taylor, Robert A. Weiss.
Application Number | 20130261436 13/902654 |
Document ID | / |
Family ID | 39940059 |
Filed Date | 2013-10-03 |
United States Patent
Application |
20130261436 |
Kind Code |
A1 |
Hennings; David R. ; et
al. |
October 3, 2013 |
Sonic Endovenous Catheter
Abstract
A device and method to improve the ultrasound visibility of a
catheter placed inside the body is described. The catheter is
sonically vibrated by an external driver device that transmits the
acoustic vibration down the catheter and inside the body. An
ultrasound transducer is used to pick up the ultrasound vibrations
directly or detects the sonic vibrations using a Doppler mode
ultrasound machine.
Inventors: |
Hennings; David R.;
(Roseville, CA) ; Lindsay; Craig; (Roseville,
CA) ; Fullmer; David J.; (Roseville, CA) ;
Taylor; Eric B.; (Roseville, CA) ; Weiss; Robert
A.; (Hunt Valley, MD) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
CoolTouch Incorporated |
Roseville |
CA |
US |
|
|
Assignee: |
CoolTouch Incorporated
Roseville
CA
|
Family ID: |
39940059 |
Appl. No.: |
13/902654 |
Filed: |
May 24, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11928624 |
Oct 30, 2007 |
8448644 |
|
|
13902654 |
|
|
|
|
60864101 |
Nov 2, 2006 |
|
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Current U.S.
Class: |
600/424 |
Current CPC
Class: |
A61B 8/488 20130101;
A61B 8/0833 20130101; A61B 8/0841 20130101; A61M 25/01 20130101;
A61H 23/00 20130101; A61B 18/245 20130101; A61B 2090/378 20160201;
A61B 8/12 20130101; A61M 2025/0166 20130101; A61B 2090/3929
20160201 |
Class at
Publication: |
600/424 |
International
Class: |
A61B 8/08 20060101
A61B008/08; A61B 18/24 20060101 A61B018/24; A61B 8/12 20060101
A61B008/12 |
Claims
1. A method to enhance visibility of a catheter device during an
endovascular treatment, the method comprising: vibrating a catheter
device, cannula or probe; and ultrasonically imaging the catheter
device, cannula or probe.
2. The method of claim 1 in which the step of vibrating the
catheter device, cannula or probe comprises providing a rotational,
translational or longitudinal movement thereto.
3. The method of claim 1 in which the catheter, cannula or probe is
vibrated at a frequency of between about 10 Hz and about 3000
Hz.
4. The method of claim 1 in which the catheter, cannula or probe is
vibrated at a frequency of between about 100 Hz and about 1000
Hz.
5. The method of claim 1 in which the catheter, cannula or probe is
vibrated at a frequency of about 500 Hz.
6. The method of claim 1 in which the vibration frequency and
intensity of vibration is adjusted and optimized for maximum
visibility using Doppler capability of an ultrasonic-imaging
machine.
7. The method of claim 1 further comprising the step of coupling
the vibrating device catheter or probe outside the body such that
the vibrations are transmitted along the catheter into the
body.
8. The method of claim 1 in which the vibrating device is built
into the catheter or probe and the vibrating is initiated from
within the body.
9. The method of claim 1 further comprising the step of removably
coupling the catheter to be vibrated to a handpiece that
incorporates the vibrator.
10. A method performing a medical treatment inside a body lumen or
cavity under visualization comprising: introducing a catheter
device, cannula or other functional probe into a body lumen or
cavity; vibrating the catheter device, cannula or other functional
probe; and ultrasonically imaging the catheter device, cannula or
other functional probe.
11. The method of claim 10 further comprising: coupling a vibration
emitter to the catheter device, cannula or other functional probe,
said vibration emitter selected from the group consisting of
oscillating motors, rotary and other stepper motors, galvanometers,
linear motors and out of balance or eccentrically weighted
motors.
12. A method to enhance visibility of a catheter device, cannula or
other functional probe while performing endovascular treatment
comprising: introducing an endoscopic catheter, cannula or other
functional probe having a tip and a length into a vein, wherein the
endoscopic catheter, cannula, or other functional probe comprises
an optical fiber; coupling a vibration emitter to the catheter,
cannula or other functional probe; using the vibration emitter to
vibrate the catheter, cannula, or other functional probe such that
transverse wave vibrations are generated along the catheter,
cannula, or other functional probe that propagate the length of the
catheter, cannula, or other functional probe at an adjustable
frequency of between 10 and 3000 Hz inside the vein; visualizing
the tip of the endoscopic catheter, cannula or other functional
probe.
13. The method of claim 12 further comprising: manually selecting
an amplitude of the wave vibrations generated by the vibration
emitter.
14. The method of claim 12 further comprising: manually selecting
the adjustable frequency of the wave vibrations generated by the
vibration emitter.
15. The method of claim 12 further comprising: selecting the
vibration emitter from the group consisting of oscillating motors,
rotary and other stepper motors, galvanometers, linear motors and
out of balance or eccentrically weighted motors.
16. The method of claim 12 wherein the optical fiber has a diameter
between 100 .mu.m and 1000 .mu.m.
17. The method of claim 12 further comprising: delivering laser
energy from the catheter, cannula, or other functional probe to the
vein.
18. The method of claim 12 further comprising: visualizing the tip
of the catheter, cannula or other functional probe using Doppler
shifted ultrasound imaging.
19. The method of claim 12 further comprising: vibrating a catheter
device, cannula or other functional probe, and ultrasonically
imaging the catheter device, cannula or other functional probe by
imposing a Doppler or equivalent frequency shift on the return
ultrasound signal.
Description
RELATED APPLICATIONS
[0001] This Application is a divisional application of U.S. patent
application Ser. No. 11/928,624 filed Oct. 30, 2007, soon to be
issued U.S. Pat. No. 8,448,644, issue date May 28, 2013, entitled
SONIC ENDOVENOUS CATHETER, Attorney Docket No. CTI-1201, which is a
non-provisional application and related to now abandoned U.S.
Provisional Patent Application Ser. No. 60/864,101 filed Nov. 2,
2006 entitled SONIC ENDOVENOUS CATHETER, Attorney Docket No.
CTI-1201-P, which are all incorporated herein by reference in their
entirety, and claims any and all benefits to which they are
entitled therefrom.
FIELD OF THE INVENTION
[0002] This device is related to imaging of catheter devices placed
inside the body for the diagnosis or treatment of internal
diseases. This device is also used to reduce the perceived pain of
tumescent anesthesia injections and to induce vein spasm when
treating venous disease to help drain the vessel of blood.
BACKGROUND OF THE INVENTION
[0003] Ultrasound and ultrasonic imaging has made great advances in
recent years do to improved transducers, computer analysis of the
return signal and the incorporation of Doppler analysis of the
image. US equipment is standard equipment in all hospitals and many
clinics. The use of ultrasound is critical for locating catheters
in veins during endovascular procedures. In most cases the
resolution and gain of current equipment is sufficient to see the
catheter and interpret the image, although it is common to use a
specially trained technician to operate the device because it does
require training and skill that few doctors have. The Doppler mode
on these ultrasound machines is typically used to show movement of
blood in veins or arteries. The Doppler frequency shift of sound
that reflects of moving objects is displayed with a color on the
ultrasound image that shows tissue or blood movement. The intensity
and duration of this movement can be used to diagnose reflux in leg
veins that are caused by incompetent valves and result in varicose
veins.
[0004] Doppler is also used to image blood flowing in the heart to
show efficiency and functionality of heart valves. When the target
structure is very deep in tissue as when imaging veins in the
thigh, it can be very hard to resolve the structure. In fact,
imaging the end of the catheter is considered to be one of the most
difficult parts of an endovenous procedure such as varicose vein
treatment. In many cases, if the catheter is not imaged properly it
is possible to treat the wrong section of the vein or even the
wrong vein causing severe complications or even death. There is a
great need to improve the ability to see inside the body. It would
be advantageous to enhance the visibility of the location of
catheters.
[0005] In addition there is a need to drain blood and reduce the
diameter of vessels during endovenous ablation for the treatment of
varicose veins. This can be accomplished by elevating the leg,
applying compression, or injecting vasoconstrictors near the vein.
It is also possible to cause the vein to shrink in size and force
out blood by stimulating the vein to react in a way that is called
a "spasm". This is a natural body reaction to insult or injury that
helps protect the venous system. During some types of surgery,
particularly endovenous ablation, it helps to try to force the vein
to spasm after the catheter is inserted so blood is forced out of
the vein that may interfere with the ablation process. The prior
art fails to teach a device that is able to vibrate inside the vein
at about 500 Hz and tickling the entire internal length of the
vein.
[0006] Pain management is a big part of the practice of many
doctors, especially since more procedures are being done under
local anesthesia in the doctor's office instead of in the hospital
under general anesthesia. With the patient awake, the practice of
certain procedures requires different techniques to prevent the
patient from perceiving pain. It has been known that it is possible
to distract patients from pain sensations and to stimulate nerves
with a secondary sensation that blocks the transmission of a pain.
Dentists commonly do this by pinching the cheek prior to injecting
anesthesia and the vibrations from a motorized liposuction probe
can mask the sensations of a needle penetrating the skin The prior
art fails to teach a way to do this inside the body in previously
inaccessible locations by transmitting the distracting vibrations
down a catheter or probe to the internal treatment site.
[0007] Prior devices to enhance imaging of internal structures
using sound energy have concentrated on a couple of techniques:
[0008] 1. Increasing the acoustic reflectivity of devices inserted
into the body.
[0009] 2. Placing ultrasound transducers on the device inside the
body and detecting the emissions externally.
[0010] 3. Transmitting longitudinal US waves down waveguides into
the body and detecting the return waves along the same
waveguide.
[0011] One major disadvantage of prior art imaging systems is the
very low signal to noise ration of the technology. When the device
to be imaged has an acoustic reflectivity that is close to that of
the surrounding tissue it is very hard to get enough sound to
bounce off of it to be imaged. This is especially true for small
objects like a fiber optic catheter.
[0012] The acoustic density of glass or metal is close enough to
that of blood or tissue that a piece of glass is very hard to
image. In many cases introducing air into the tip of the catheter
is not feasible. Air to tissue has a very large difference in
acoustic density so that an air tissue interface reflects sound
very well. Many prior art devices use air to enhance imaging.
ADVANTAGES AND SUMMARY OF THE INVENTION
[0013] The present invention improves the imaging of the position
of devices inside the body. The present invention uses an auxiliary
sonic generator to transmit a relatively low frequency acoustic
energy at typically 100 to 1000 Hz into the body. The present
invention also transmits the energy using transverse mechanical
waves and not longitudinal sound waves as all prior ultrasound
techniques have utilized.
[0014] While devices of the prior art utilize ultrasound detectors
to sense the high frequency vibrations directly, the present
invention alters the ultrasound detection by imposing a Doppler or
frequency shift on the return ultrasound signal. It is this Doppler
shifted signal which can easily be imaged. No other parts of the
body are moving this speed so the contrast and signal to noise is
very high on the imaging system.
[0015] In certain embodiments, the present invention may not allow
precise imaging of fine details on the internal device. It may only
create a reflecting surface that is moving rapidly enough to be
detected under a Doppler imaging device. The main advantage of the
present system is to generate a locating signal that has a very
high signal to noise ratio. The movement potentially blurs out the
fine details that are less than the amplitude of the
oscillation.
[0016] The present invention is a method to enhance visibility of a
catheter device during an endovascular treatment. The method
includes the steps of vibrating a catheter device, cannula or probe
and ultrasonically imaging the catheter device, a cannula, or
probe.
[0017] The step of vibrating the catheter device, cannula or probe
includes providing a rotational, translational or longitudinal
movement thereto.
[0018] In a method of sonic endovenous catheter of the present
invention, the catheter, cannula or probe is vibrated at a
frequency of between about 10 Hz and about 3000 Hz.
[0019] In a method of sonic endovenous catheter of the present
invention, the catheter, cannula or probe is vibrated at a
frequency of between about 100 Hz and about 1000 Hz.
[0020] In a method of sonic endovenous catheter of the present
invention, the catheter, cannula or probe is vibrated at a
frequency of about 500 Hz.
[0021] In a method of sonic endovenous catheter of the present
invention, the vibration frequency and intensity of vibration is
adjusted and optimized for maximum visibility using Doppler
capability of an ultrasound-imaging machine.
[0022] The method of sonic endovenous catheter of the present
invention further includes the step of coupling the vibrating
device catheter or probe outside the body such that the vibrations
are transmitted along the catheter into the body.
[0023] In a method of sonic endovenous catheter of the present
invention, the vibrating device is built into the catheter or probe
and the vibrating is initiated from within the body.
[0024] The method of sonic endovenous catheter of the present
invention further includes the step of removably coupling the
catheter to be vibrated to a hand-piece that incorporates the
vibrator.
[0025] The present invention is also a method for inducing vein
spasm. The method includes the step of vibrating a device inside a
vein.
[0026] The present invention is also a method for forcing blood out
of a vein during endovascular treatment. The method includes the
steps of vibrating a catheter or probe inside a vein and inducing
vein spasm, such that the vein spasm temporarily reduces the
diameter of the vein.
[0027] The present invention is also a method for reducing pain.
The method includes the step of vibrating a catheter, a cannula or
other functional probe endoscopically placed inside a vein.
[0028] The method of sonic endovenous catheter of the present
invention further includes the step of timing the vibrations to
distract the patient and overwhelm the nerves in the area of
treatment to reduce the sensation of pain in the area of
treatment.
[0029] The method of sonic endovenous catheter of the present
invention further includes the step timing the vibrations are timed
to distract the patient and overwhelm nerves in the area of
treatment and injecting local anesthesia or tumescent
anesthesia.
[0030] The present invention is also a method for reducing pain
associated with the endoscopic insertion and/or moving of a
catheter, cannula or other functional probe. The method includes
the step of vibrating the catheter, cannula or other functional
probe placed inside a vein.
[0031] The present invention is also a system for enhancing an
endoscopic therapeutic treatment. The system includes an endoscopic
catheter, cannula or other functional probe having a predetermined
length, a vibration emitter for emitting transverse wave vibrations
along the catheter, cannula or other functional probe, apparatus
for coupling the vibration emitter to the catheter, cannula or
other functional probe, wherein transverse waves are transmitted
along the length thereof.
[0032] In the sonic endovenous catheter system of the present
invention, the amplitude of the vibrations emitted by the vibration
emitter can be selected manually.
[0033] In the sonic endovenous catheter system of the present
invention, the amplitude of the vibrations emitted by the vibration
emitter can be pre-programmed.
[0034] In the sonic endovenous catheter system of the present
invention, the frequency of the vibrations emitted by the vibration
emitter can be selected manually.
[0035] In the sonic endovenous catheter system of the present
invention, the frequency of the vibrations emitted by the vibration
emitter can be pre-programmed.
[0036] In the sonic endovenous catheter system of the present
invention, the vibration emitter operates at a rate of between
about 10 and about 3000 Hz.
[0037] In the sonic endovenous catheter system of the present
invention, the vibration emitter operates at a rate of between
about 100 and about 1000 Hz.
[0038] In the sonic endovenous catheter system of the present
invention, the vibration emitter operates at a rate of about 500
Hz.
[0039] In the sonic endovenous catheter system of the present
invention, the vibration emitter comprises a motor selected from
the group consisting of oscillating motors, rotary and other
stepper motors, galvanometers, linear motors and out of balance or
eccentrically weighted motors.
[0040] In the sonic endovenous catheter system of the present
invention, the vibration emitter transmits linear motion to the
catheter, cannula or other functional probe.
[0041] In the sonic endovenous catheter system of the present
invention, the vibration emitter transmits rotational motion to the
catheter, cannula or other functional probe.
[0042] In the sonic endovenous catheter system of the present
invention, the vibration emitter transmits sinusoidal motion to the
catheter, cannula or other functional probe.
[0043] In the sonic endovenous catheter system of the present
invention, the endoscopic catheter, cannula or other functional
probe comprises an optical fiber having a diameter between about
100 um and about 1000 um.
[0044] Further details, objects and advantages of the present
invention will be come apparent through the following descriptions,
and will be included and incorporated herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0045] FIG. 1 is a representative drawing of an oscillating
motorized device 100 clipped to a catheter 200 to produce
rotational vibrations and transverse waves 110 in the catheter 200
according to the devices and methods of the present invention.
[0046] FIG. 2 is a representative drawing of the catheter 200 image
on an ultrasound machine with and without vibrations 110 according
to the devices and methods of the present invention.
[0047] FIG. 3 are a representative drawings of the end view 152 of
the motorized vibrating device 100 showing the clip 150 to the
catheter 200 and three possible motions that will cause the entire
catheter 200 to vibrate according to the devices and methods of the
present invention.
[0048] FIG. 4 are representative drawings showing how three
vibration generators 100 can work using a rotary stepper motor, a
galvanometer, a linear motor and an out of balance weight according
to the devices and methods of the present invention.
[0049] FIG. 5 is a representative top view of one embodiment of
sterile disposable clip 150 according to the devices and methods of
the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0050] The description that follows is presented to enable one
skilled in the art to make and use the present invention, and is
provided in the context of a particular application and its
requirements. Various modifications to the disclosed embodiments
will be apparent to those skilled in the art, and the general
principals discussed below may be applied to other embodiments and
applications without departing from the scope and spirit of the
invention. Therefore, the invention is not intended to be limited
to the embodiments disclosed, but the invention is to be given the
largest possible scope which is consistent with the principals and
features described herein.
[0051] It will be understood that in the event parts of different
embodiments have similar functions or uses, they may have been
given similar or identical reference numerals and descriptions. It
will be understood that such duplication of reference numerals is
intended solely for efficiency and ease of understanding the
present invention, and are not to be construed as limiting in any
way, or as implying that the various embodiments themselves are
identical.
[0052] FIG. 1 is a representative drawing of an oscillating
motorized device 100 clipped to a catheter 200 to produce
rotational vibrations and transverse waves 110 in the catheter 200
according to the devices and methods of the present invention. FIG.
2 is a representative drawing of the catheter 200 image on an
ultrasound machine with and without vibrations or transverse waves
110 according to the devices and methods of the present
invention.
[0053] Apparatus:
[0054] As best shown in FIG. 1 and FIG. 2, an embodiment of the
present invention requires three parts: [0055] 1. A catheter 200 or
probe that is rigid and strong enough to vibrate in a transverse
manner without degrading. [0056] 2. A mechanical vibrating device
100 that moves the proximal end of the catheter a sufficient
distance to generate vibrations or transverse waves 110 that
propagate the length of the catheter 200. [0057] 3. An
ultrasound-imaging machine 300 that has a Doppler mode to view the
moving catheter 200 inside the body.
[0058] In one embodiment, catheter 200 can be an electrical wire
assembly that is used to transmit electrical or radio frequency
current. The construction can use fine wires that are flexible
enough to withstand repeated vibrations without breaking. In
alternative embodiments, catheter 200 can also be made of optical
quartz, silica or other transparent materials. In one embodiment,
catheter 200 should be thin enough to vibrate readily without
causing internal bending stresses and should have protective jacket
material over the silica to add strength. Many fiber optic
catheters 200 used to deliver laser energy are constructed in a
manner that will survive such mechanical vibrations 110.
[0059] The probe can also be a hollow cannula such as a long needle
or tube or a rigid shaft or mechanical device such as used for
obtaining biopsy samples.
[0060] FIGS. 3a, 3b, 3c and 3d are representative drawings of the
end view 152 of the motorized vibrating device 100 showing the clip
150 to the catheter 200 and three possible motions that will cause
the entire catheter 200 to vibrate according to the devices and
methods of the present invention. FIG. 4 are representative
drawings showing how three vibration generators 100 can work using
a rotary stepper motor, a galvanometer, a linear motor and an out
of balance weight according to the devices and methods of the
present invention.
[0061] FIG. 5 is a representative top view of one embodiment of
sterile disposable clip 150 according to the devices and methods of
the present invention. Sterile disposable clip 150 has a proximal
end 156 which couples to the oscillating motor 100, and a distal
end groove 154 which clips the distal end 152 of the sterile
disposable tip 150 to the catheter 200. In one embodiment, sterile
disposable clip 150 further has one or more finger grip(s) 158 for
conveniently connecting sterile disposable clip 150 to oscillating
motor 100.
[0062] A transverse wave 110 is one in which the direction of
displacement at each point of the medium is parallel to the
wavefront, or a wave in which the vibration is moving in a
direction perpendicular as that in which the wave is traveling. In
a transverse wave the medium moves at right angles to the wave
direction. For example: if a wave moves along the x-axis, its
oscillations are in the y-z plane. In other words, it oscillates
across the 2-dimensional plane that it is traveling in. It may
oscillate either vertically or horizontally, and this refers to its
polarity. Water waves are an example of transverse waves.
Electromagnetic waves are also transverse waves.
[0063] As best shown in FIG. 3 and FIG. 4, the mechanical vibrating
device 100 can operate in several modes to generate transverse wave
motion 110 in the catheter 200. As best shown in FIG. 3b and FIG.
4a, in one embodiment, a rotary motion E can be used to twist the
catheter 200 back and forth through about plus or minus 15 degrees.
In one embodiment, a rotary motion E can be generated by a stepper
motor 102 such as available from AMCI or Danaher Motion which is
stepped back and forth through one step. An electronic galvanometer
such as available from General Scanning can be used which has a
shaft that is connected to electromagnets in a coil. When
alternating current is applied to the coils the shaft will
oscillate through a small angle in either a driven or a resonant
fashion. A stepper motor 102, where an internal rotor containing
permanent magnets is controlled by a set of external magnets that
are switched electronically. A stepper motor 102 is a cross between
a DC electric motor and a solenoid. A stepper motor 102 is a type
of electric motor which is used when something has to be positioned
very precisely or rotated by an exact angle. Simple stepper motors
102 "cog" to a limited number of positions, but proportionally
controlled stepper motors can rotate extremely smoothly. Computer
controlled stepper motors 102 are one of the most versatile forms
of positioning systems, particularly when part of a digital
servo-controlled system. In a stepper motor 102, an internal rotor
containing permanent magnets is controlled by a set of stationary
electromagnets that are switched electronically. Hence, it is a
cross between a DC electric motor and a solenoid. Stepper motors
102 do not use brushes and commutators. Stepper motors 102 have a
fixed number of magnetic poles that determine the number of steps
per revolution. Most common stepper motors 102 have 200 full
steps/revolution, meaning it takes 200 full steps to turn one
revolution. Advanced stepper motor 102 controllers can utilize
pulse-width modulation to perform microsteps, achieving higher
position resolution and smoother operation. Some microstepping
controllers can increase the step resolution from 200 steps/rev to
50,000 microsteps/rev. Stepper motors 102 are rated by the torque
they produce. A unique feature of steppers is their ability to
provide position holding torque while not in motion. To achieve
full rated torque, the coils in a stepper motor 102 must reach
their full rated current during each step. Stepper motor 102
drivers must employ current regulating circuits to realize this.
The voltage rating (if there is one) is almost meaningless.
Computer controlled stepper motors 102 are one of the most
versatile forms of positioning systems, particularly when digitally
controlled as part of a servo system.
[0064] In an alternative embodiment, as best shown in FIG. 4b, a
linear motion F can be produced by a linear motor 104. A linear
motor 104 is essentially an electric motor that has been "unrolled"
so that instead of producing a torque (rotation), it produces a
linear force along its length by setting up a traveling
electromagnetic field. Linear motors 104 are most commonly
induction motors or stepper motors. You can find a linear motor in
a maglev (Transrapid) train, where the train "flies" over the
ground.
[0065] In yet another alternative embodiment, as best shown in
FIGS. 3c and 4c, a up and down motion G can be produced by an out
of balance arc motor 106.
[0066] Methods of Use:
[0067] FIG. 2 is a representative drawing of the catheter 200 image
on an ultrasound machine with and without vibrations 110 according
to the devices and methods of the present invention. An embodiment
of an imaging procedure is as follows: [0068] 1. The Ultrasound
Imaging device such as made by GE, or others is placed over the
section of body of interest. For example, in the case of performing
endovascular laser ablation to treat varicose veins, the transducer
head of the ultrasound device could be placed to image the
saphenofemoral junction (SFJ). [0069] 2. Insert the catheter 200
into the vein from an access point near the knee and move it toward
the SFJ. It is critical that the ablation catheter 200 be placed
precisely 1-2 cm below this junction or damage to femoral vein
could occur with severe consequences to the patient. Using
conventional passive ultrasound, it is usually very hard to see the
image of the catheter 202 or the catheter tip 204 at this site as
best shown in FIG. 2(a). [0070] 3. Attach the external sonic
vibrator device 100 described above to the catheter 200 just
outside the access point to the vein, and turn on to vibrate the
catheter 200 in a transverse manner down through the vein to the
tip. Switch the ultrasound-imaging machine to Doppler mode, as best
shown in FIG. 2(b), and look for the characteristic color pattern
206 created by moving objects. Move the catheter 200 slowly in and
out until the color pattern is properly positioned. [0071] 4. The
intensity of the color Doppler pattern 206 may be adjusted by
changing the external vibration 110 frequency or intensity. It is
advantageous to not overwhelm the image of the vein at the same
time but to adjust the signal strength so that the tip of the
catheter 208 and the vein are both visible at the same time.
[0072] Experimental Results:
[0073] A branched vessel phantom made by Advanced Medical
Technologies, Select Series Branched 4 Vessel Vascular Access
Phantom by Blue Phantom PN BPBV 110, filled with water was used to
simulate a vein inside the body. A 600 um endovenous ablation
catheter was placed in one of the vein lumens through a silicone
tube to simulate vein transmission. A Diasonics Spectra Plus
ultrasound-imaging machine with a 5 MHz linear array coupled with
gel was used to image the catheter in the phantom. After the vein
was located in the phantom under ultrasound, the catheter was
inserted to the desired location. The gain on the ultrasound was
reduced until the catheter was no longer visible to simulate
imaging deep within the body. An oscillating motor was attached to
the catheter about 24 inches from the imaging site. The motor
rotated through 30 degrees of movement at about 500 Hz causing the
catheter to vibrate in large standing waves that had about 5 mm of
amplitude outside the phantom. Inside the phantom it was estimated
that the catheter moved approximately 1 mm in a transverse
vibration. Under ultrasound with the Doppler mode, this movement
was seen as a large colored area that had a distinct end point to
it. After the gain of the ultrasound was reduced, it was possible
to see exactly where the catheter was located. The end of the
catheter signal moved in and out clearly with catheter movement
from outside.
[0074] Subsequently, the catheter was "life tested" to determine
the fatigue that the vibrations may impose on the catheter. The
catheter, a 600 um quartz endovenous probe, was vibrated for an
additional one hour without any signs of degradation. The vibration
time in vivo should be a minute or less. The simulated life test
was considered successful, and further testing will determine mean
time before failure, usable life expectancy, etc. Tests also show
that the 365 um fiber works better inside the leg than the thicker
600 um fiber.
[0075] Guideline for the Use of Sonic Vibrator
[0076] Pre Operation:
[0077] 1. Make sure that handle is charged. A full charge will last
for about 30 mm of use as indicated by 3 or more green leds on the
handle.
[0078] 2. Sterilize fiber clip by autoclaving in pouch for 270
degrees F. for 3 mm or 250 deg F. for 15 mm.
[0079] Sterile Field:
[0080] 1. Place sonic handle in sterile Ultrasound probe bag.
[0081] 2. Place fiber clip onto handle through sterile bag. Make
sure that it is tight onto handle.
[0082] 3. Advance fiber through sheath in vein until it is
approximately at the proper place.
[0083] 4. Set Ultra Sound to doppler mode and image the
location.
[0084] 5. Choose a location on the fiber about 2 inches outside
sheath to place the sonic vibrator.
[0085] 6. Slide the fiber into the slot at the end of fiber clip
making sure that it is fully engaged and tight in the slot.
[0086] 7. Press light green "ON" button on the sonic handle to
vibrate fiber. It may be necessary to tape or hold the free side of
the fiber to prevent it from vibrating excessively outside the leg.
The fiber should stay attached in the slot in the fiber clip. If it
falls out, push it back in.
[0087] 8. The sonic handle may turn off by itself in about 1
minute. Simply press the light green button to re start it. The
handle may also pause occasionally but re-start by itself.
[0088] 9. Locate the end of the fiber by locating the color pattern
generated by the Doppler image. Turn down the gain of the US if
necessary to get better resolution. The tip of the fiber should
show as a clean end to the color return. Move the fiber in or out
of the sheath to position the fiber in the vein.
[0089] 10. Turn the sonic handle off by pressing the light green
button again and remove the fiber from the holder.
[0090] 11. Slip a white donut marker over the fiber at the end of
the sheath to mark the fiber position.
[0091] 12. Proceed with the endovenous ablation.
[0092] 13. The fiber clip may be reused.
[0093] Unless defined otherwise, all technical and scientific terms
used herein have the same meaning as commonly understood by one of
ordinary skill in the art to which the present invention belongs.
Although any methods and materials similar or equivalent to those
described can be used in the practice or testing of the present
invention, the preferred methods and materials are now described.
All publications and patent documents referenced in the present
invention are incorporated herein by reference.
[0094] While the principles of the invention have been made clear
in illustrative embodiments, there will be immediately obvious to
those skilled in the art many modifications of structure,
arrangement, proportions, the elements, materials, and components
used in the practice of the invention, and otherwise, which are
particularly adapted to specific environments and operative
requirements without departing from those principles. The appended
claims are intended to cover and embrace any and all such
modifications, with the limits only of the true purview, spirit and
scope of the invention.
* * * * *