U.S. patent application number 15/285342 was filed with the patent office on 2017-06-15 for intravascular ultrasound systems, catheters, and methods with a manual pullback arrangement.
The applicant listed for this patent is Boston Scientific SciMed, Inc.. Invention is credited to John D. Marshall, Lewis J. Thomas, III, Peter Thornton, JR., Gaylin Mildred Yee, Isaac J. Zacharias.
Application Number | 20170164925 15/285342 |
Document ID | / |
Family ID | 57137308 |
Filed Date | 2017-06-15 |
United States Patent
Application |
20170164925 |
Kind Code |
A1 |
Marshall; John D. ; et
al. |
June 15, 2017 |
INTRAVASCULAR ULTRASOUND SYSTEMS, CATHETERS, AND METHODS WITH A
MANUAL PULLBACK ARRANGEMENT
Abstract
A catheter assembly for an ultrasound system can include an
integrated pullback arrangement. For example, the catheter assembly
can include a telescoping pullback section having a first
telescope, a second telescope, a distal grip coupling one of the
first or second telescope to the distal sheath of the distal
section, and a proximal grip coupled to another of the first or
second telescope so that the first telescope can be retracted into
the second telescope and a sensor to determine a position of the
first telescope. Another example includes the sensor and a pullback
slider arrangement having a housing defining a slit, a coupler
disposed within the housing, and a slider handle extending through
the slit and coupled to the coupler. In another example, the
coupler and housing can be gripped and slid relative to each
other.
Inventors: |
Marshall; John D.; (Los
Gatos, CA) ; Thornton, JR.; Peter; (Los Altos,
CA) ; Thomas, III; Lewis J.; (Palo Alto, CA) ;
Zacharias; Isaac J.; (Pleasanton, CA) ; Yee; Gaylin
Mildred; (Newark, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Boston Scientific SciMed, Inc. |
Maple Grove |
MN |
US |
|
|
Family ID: |
57137308 |
Appl. No.: |
15/285342 |
Filed: |
October 4, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62239736 |
Oct 9, 2015 |
|
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|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61B 8/0891 20130101;
A61B 5/0402 20130101; A61B 8/14 20130101; A61B 8/445 20130101; A61B
8/4245 20130101; A61B 8/4483 20130101; A61B 8/12 20130101 |
International
Class: |
A61B 8/12 20060101
A61B008/12; A61B 5/0402 20060101 A61B005/0402; A61B 8/08 20060101
A61B008/08; A61B 8/14 20060101 A61B008/14; A61B 8/00 20060101
A61B008/00 |
Claims
1. A catheter assembly for an ultrasound system, the catheter
assembly comprising: a distal section comprising a distal sheath; a
proximal extension comprising a proximal sheath; a telescoping
pullback section between the distal section and the proximal
extension, the telescoping pullback section comprising a first
telescope, a second telescope, a distal grip coupling one of the
first or second telescope to the distal sheath of the distal
section, and a proximal grip coupled to another of the first or
second telescope, wherein the first telescope can be retracted into
the second telescope by gripping the distal and proximal grips and
manually moving the distal and proximal grips away from each other;
a sensor disposed along the telescoping pullback section to
determine a position of the first telescope as the first telescope
is moved relative to the sensor; an elongated, rotatable driveshaft
having a proximal end and a distal end and extending along the
distal section, proximal extension, and telescoping pullback
section, wherein the proximal end is configured and arranged for
coupling to a motordrive for rotating the driveshaft; an imaging
device coupled to the distal end of the driveshaft with rotation of
the driveshaft causing a corresponding rotation of the imaging
device, the imaging device comprising at least one transducer
configured and arranged for transforming applied electrical signals
to acoustic signals and also for transforming received echo signals
to electrical signals; and at least one conductor extending along
the distal section, proximal extension, and telescoping pullback
section and coupled to the imaging device for carrying the
electrical signals.
2. The catheter assembly of claim 1, wherein the first telescope is
distal to the second telescope.
3. The catheter assembly of claim 2, further comprising a housing
disposed at a distal end of the second telescope, wherein the
sensor is disposed in the housing.
4. The catheter assembly of claim 2, wherein the proximal grip is
disposed at a distal end of the second telescope.
5. The catheter assembly of claim 1, wherein the sensor is disposed
in the proximal grip.
6. The catheter assembly of claim 1, wherein the sensor is an
optical sensor and the first telescope comprises a set of
alternating stripes of different colors detectable by the optical
sensor to determine a position of the first telescope.
7. The catheter assembly of claim 1, wherein the sensor is a
resistive, capacitive, inductive, or magnetic sensor.
8. The catheter assembly of claim 1, wherein the proximal grip
comprises at least one control button, wherein actuation of a one
of the at least one control button provides a signal related to a
pullback procedure.
9. A catheter assembly for an ultrasound system, the catheter
assembly comprising: a distal section comprising a distal sheath; a
proximal extension comprising a proximal sheath; a pullback slider
arrangement disposed between the distal section and the proximal
extension, the pullback slider arrangement comprising a housing
defining a slit, a coupler disposed within the housing, and a
slider handle extending through the slit and coupled to the
coupler, wherein the slider handle and the coupler can be manually
slid along the slit in the housing; a sensor disposed within the
housing of the pullback slider arrangement to determine a position
of the coupler within the housing; an elongated, rotatable
driveshaft having a proximal end and a distal end and extending
along the distal section, proximal extension, and pullback slider
arrangement, wherein the proximal end is configured and arranged
for coupling to a motordrive for rotating the driveshaft, wherein
the coupler of the pullback slider arrangement is coupled to the
rotatable driveshaft to manually move the rotatable driveshaft
backwards and forwards by moving the slider handle; an imaging
device coupled to the distal end of the driveshaft with rotation of
the driveshaft causing a corresponding rotation of the imaging
device, the imaging device comprising at least one transducer
configured and arranged for transforming applied electrical signals
to acoustic signals and also for transforming received echo signals
to electrical signals; and at least one conductor extending along
the distal section, proximal extension, and telescoping pullback
section and coupled to the imaging device for carrying the
electrical signals.
10. The catheter assembly of claim 9, wherein the housing of the
pullback slider arrangement comprises at least one control button,
wherein actuation of a one of the at least one control button
provides a signal related to a pullback procedure.
11. The catheter assembly of claim 9, wherein the sensor is an
optical, resistive, capacitive, inductive, or magnetic sensor.
12. The catheter assembly of claim 9, wherein the sensor is a
potentiometer.
13. The catheter assembly of claim 9, wherein the sensor is a
capacitive sensor and comprises a first plate and a second plate
that is coupled to the coupler of the pullback slider arrangement
so that capacitance between the first and second plates varies with
position of the coupler.
14. The catheter assembly of claim 9, wherein the sensor is an
inductive sensor and comprises a coil and a magnetic material that
is coupled to the coupler of the pullback slider arrangement and
moves with the coupler so that inductance of the coil varies with
position of the coupler.
15. The catheter assembly of claim 9, wherein the sensor is an
optical sensor coupled to the coupler and the pullback slider
arrangement comprises a set of alternating stripes of different
colors detectable by the optical sensor and disposed in the housing
to determine a position of the coupler.
16. The catheter assembly of claim 9, wherein the sensor is a
magnetic sensor coupled to the coupler and the pullback slider
arrangement comprises a set of alternating stripes of magnetic
materials detectable by the magnetic sensor and disposed in the
housing to determine a position of the coupler.
17. A catheter assembly for an ultrasound system, the catheter
assembly comprising: a distal section comprising a distal sheath; a
proximal extension comprising a proximal sheath; a pullback slider
arrangement disposed between the distal section and the proximal
extension, the pullback slider arrangement comprising a housing
defining an opening and a coupler disposed partially within the
housing and extending through the opening in the housing, wherein
the coupler can slide relative to the housing to change a size of a
portion of the coupler disposed within the housing; a sensor
disposed within the housing of the pullback slider arrangement to
determine a position of the coupler relative to the housing; an
elongated, rotatable driveshaft having a proximal end and a distal
end and extending along the distal section, proximal extension, and
pullback slider arrangement, wherein the proximal end is configured
and arranged for coupling to a motordrive for rotating the
driveshaft, wherein the coupler of the pullback slider arrangement
is coupled to the rotatable driveshaft to manually move the
rotatable driveshaft backwards and forwards by moving the slider
handle; an imaging device coupled to the distal end of the
driveshaft with rotation of the driveshaft causing a corresponding
rotation of the imaging device, the imaging device comprising at
least one transducer configured and arranged for transforming
applied electrical signals to acoustic signals and also for
transforming received echo signals to electrical signals; and at
least one conductor extending along the distal section, proximal
extension, and telescoping pullback section and coupled to the
imaging device for carrying the electrical signals.
18. The catheter assembly of claim 17, wherein the sensor is an
optical sensor coupled to the housing and the coupler comprises a
set of alternating stripes of different colors detectable by the
optical sensor to determine a position of the coupler.
19. The catheter assembly of claim 17, wherein the sensor is a
magnetic sensor coupled to the housing and the coupler comprises a
set of alternating stripes of magnetic materials detectable by the
magnetic sensor to determine a position of the coupler.
20. The catheter assembly of claim 17, wherein the housing defines
a slit and the coupler comprises a flush port that extends out of
the slit.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit under 35 U.S.C.
.sctn.119(e) of U.S. Provisional Patent Application Ser. No.
62/239,736, filed Oct. 9, 2015, which is incorporated herein by
reference.
TECHNICAL FIELD
[0002] The present invention is directed to the area of ultrasound
imaging systems and methods of making and using the systems. The
present invention is also directed to an ultrasound imaging system
and catheter that includes a manual pullback arrangement, as well
as methods of making and using the ultrasound systems and
catheters.
BACKGROUND
[0003] Ultrasound devices insertable into patients have proven
diagnostic capabilities for a variety of diseases and disorders.
For example, intravascular ultrasound ("IVUS") imaging systems have
been used as an imaging modality for diagnosing blocked blood
vessels and providing information to aid medical practitioners in
selecting and placing stents and other devices to restore or
increase blood flow. IVUS imaging systems have been used to
diagnose atheromatous plaque build-up at particular locations
within blood vessels. IVUS imaging systems can be used to determine
the existence of an intravascular obstruction or stenosis, as well
as the nature and degree of the obstruction or stenosis. IVUS
imaging systems can be used to visualize segments of a vascular
system that may be difficult to visualize using other intravascular
imaging techniques, such as angiography, due to, for example,
movement (e.g., a beating heart) or obstruction by one or more
structures (e.g., one or more blood vessels not desired to be
imaged). IVUS imaging systems can be used to monitor or assess
ongoing intravascular treatments, such as angiography and stent
placement in real (or almost real) time. Moreover, IVUS imaging
systems can be used to monitor one or more heart chambers.
[0004] IVUS imaging systems have been developed to provide a
diagnostic tool for visualizing a variety of diseases or disorders.
An IVUS imaging system can include a control module (with a pulse
generator, an image processor, and a monitor), a catheter, and one
or more transducers disposed in the catheter. The
transducer-containing catheter can be positioned in a lumen or
cavity within, or in proximity to, a region to be imaged, such as a
blood vessel wall or patient tissue in proximity to a blood vessel
wall. The pulse generator in the control module generates
electrical signals that are delivered to the one or more
transducers and transformed to acoustic signals that are
transmitted through patient tissue. Reflected signals of the
transmitted acoustic signals are absorbed by the one or more
transducers and transformed to electric signals. The transformed
electric signals are delivered to the image processor and converted
to an image displayable on the monitor.
[0005] Intracardiac echocardiography ("ICE") is another ultrasound
imaging technique with proven capabilities for use in diagnosing
intravascular diseases and disorders. ICE uses acoustic signals to
image patient tissue. Acoustic signals emitted from an ICE imager
disposed in a catheter are reflected from patient tissue and
collected and processed by a coupled ICE control module to form an
image. ICE imaging systems can be used to image tissue within a
heart chamber.
BRIEF SUMMARY
[0006] One embodiment is a catheter assembly for an ultrasound
system that includes a distal section having a distal sheath; a
proximal extension having a proximal sheath; and a telescoping
pullback section between the distal section and the proximal
extension and having a first telescope, a second telescope, a
distal grip coupling one of the first or second telescope to the
distal sheath of the distal section, and a proximal grip coupled to
another of the first or second telescope. The first telescope can
be retracted into the second telescope by gripping the distal and
proximal grips and manually moving the distal and proximal grips
away from each other. The catheter assembly also includes a sensor
disposed along the telescoping pullback section to determine a
position of the first telescope as the first telescope is moved
relative to the sensor; an elongated, rotatable driveshaft having a
proximal end and a distal end and extending along the distal
section, proximal extension, and telescoping pullback section with
the proximal end configured and arranged for coupling to a
motordrive for rotating the driveshaft; an imaging device coupled
to the distal end of the driveshaft with rotation of the driveshaft
causing a corresponding rotation of the imaging device, the imaging
device including at least one transducer for transforming applied
electrical signals to acoustic signals and also for transforming
received echo signals to electrical signals; and at least one
conductor extending along the distal section, proximal extension,
and telescoping pullback section and coupled to the imaging device
for carrying the electrical signals.
[0007] In at least some embodiments, the first telescope is distal
to the second telescope. In at least some embodiments, the catheter
assembly further includes a housing disposed at a distal end of the
second telescope with the sensor disposed in the housing. In at
least some embodiments, the proximal grip is disposed at a distal
end of the second telescope. In at least some embodiments, the
sensor is disposed in the proximal grip.
[0008] In at least some embodiments, the sensor is an optical
sensor and the first telescope includes a set of alternating
stripes of different colors detectable by the optical sensor to
determine a position of the first telescope. In at least some
embodiments, the sensor is a resistive, capacitive, inductive, or
magnetic sensor. In at least some embodiments, the proximal grip
includes at least one control button, where actuation of one of the
at least one control button provides a signal related to a pullback
procedure.
[0009] Another embodiment is a catheter assembly for an ultrasound
system that includes a distal section having a distal sheath; a
proximal extension having a proximal sheath; and a pullback slider
arrangement disposed between the distal section and the proximal
extension. The pullback slider arrangement includes a housing
defining a slit, a coupler disposed within the housing, and a
slider handle extending through the slit and coupled to the
coupler, wherein the slider handle and the coupler can be manually
slid along the slit in the housing. The catheter assembly also
includes a sensor disposed within the housing of the pullback
slider arrangement to determine a position of the coupler within
the housing; an elongated, rotatable driveshaft having a proximal
end and a distal end and extending along the distal section,
proximal extension, and pullback slider arrangement with the
proximal end configured and arranged for coupling to a motordrive
for rotating the driveshaft, where the coupler of the pullback
slider arrangement is coupled to the rotatable driveshaft to
manually move the rotatable driveshaft backwards and forwards by
moving the slider handle; an imaging device coupled to the distal
end of the driveshaft with rotation of the driveshaft causing a
corresponding rotation of the imaging device, the imaging device
including at least one transducer configured and arranged for
transforming applied electrical signals to acoustic signals and
also for transforming received echo signals to electrical signals;
and at least one conductor extending along the distal section,
proximal extension, and telescoping pullback section and coupled to
the imaging device for carrying the electrical signals.
[0010] In at least some embodiments, the housing of the pullback
slider arrangement includes at least one control button, where
actuation of one of the at least one control button provides a
signal related to a pullback procedure. In at least some
embodiments, the sensor is an optical, resistive, capacitive,
inductive, or magnetic sensor. In at least some embodiments, the
sensor is a potentiometer. In at least some embodiments, the sensor
is a capacitive sensor and includes a first plate and a second
plate that is coupled to the coupler of the pullback slider
arrangement so that capacitance between the first and second plates
varies with position of the coupler. In at least some embodiments,
the sensor is an inductive sensor and includes a coil and a
magnetic material that is coupled to the coupler of the pullback
slider arrangement and moves with the coupler so that inductance of
the coil varies with position of the coupler.
[0011] In at least some embodiments, the sensor is an optical
sensor coupled to the coupler and the pullback slider arrangement
includes a set of alternating stripes of different colors
detectable by the optical sensor and disposed in the housing to
determine a position of the coupler. In at least some embodiments,
the sensor is a magnetic sensor coupled to the coupler and the
pullback slider arrangement includes a set of alternating stripes
of magnetic materials detectable by the magnetic sensor and
disposed in the housing to determine a position of the coupler.
[0012] Yet another embodiment is a catheter assembly for an
ultrasound system that includes a distal section having a distal
sheath; a proximal extension having a proximal sheath; and a
pullback slider arrangement disposed between the distal section and
the proximal extension. The pullback slider arrangement includes a
housing defining an opening and a coupler disposed partially within
the housing and extending through the opening in the housing, where
the coupler can slide relative to the housing to change a size of a
portion of the coupler disposed within the housing. The catheter
assembly further includes a sensor disposed within the housing of
the pullback slider arrangement to determine a position of the
coupler relative to the housing; an elongated, rotatable driveshaft
having a proximal end and a distal end and extending along the
distal section, proximal extension, and pullback slider
arrangement, where the proximal end is configured and arranged for
coupling to a motordrive for rotating the driveshaft, where the
coupler of the pullback slider arrangement is coupled to the
rotatable driveshaft to manually move the rotatable driveshaft
backwards and forwards by moving the slider handle; an imaging
device coupled to the distal end of the driveshaft with rotation of
the driveshaft causing a corresponding rotation of the imaging
device, the imaging device including at least one transducer
configured and arranged for transforming applied electrical signals
to acoustic signals and also for transforming received echo signals
to electrical signals; and at least one conductor extending along
the distal section, proximal extension, and telescoping pullback
section and coupled to the imaging device for carrying the
electrical signals.
[0013] In at least some embodiments, the sensor is an optical
sensor coupled to the housing and the coupler includes a set of
alternating stripes of different colors detectable by the optical
sensor to determine a position of the coupler. In at least some
embodiments, the sensor is a magnetic sensor coupled to the housing
and the coupler includes a set of alternating stripes of magnetic
materials detectable by the magnetic sensor to determine a position
of the coupler. In at least some embodiments, the housing defines a
slit and the coupler includes a flush port that extends out of the
slit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Non-limiting and non-exhaustive embodiments of the present
invention are described with reference to the following drawings.
In the drawings, like reference numerals refer to like parts
throughout the various figures unless otherwise specified.
[0015] For a better understanding of the present invention,
reference will be made to the following Detailed Description, which
is to be read in association with the accompanying drawings,
wherein:
[0016] FIG. 1 is a schematic view of one embodiment of an
intravascular ultrasound imaging system, according to the
invention;
[0017] FIG. 2 is a schematic side view of one embodiment of an
imaging module of an intravascular ultrasound imaging system,
according to the invention;
[0018] FIG. 3 is a schematic perspective view of one embodiment of
a distal end of the catheter shown in FIG. 1 with an imaging core
disposed in a lumen defined in the catheter, according to the
invention;
[0019] FIG. 4 is a schematic side view of a portion of one
embodiment of a catheter with a telescoping pullback section,
according to the invention;
[0020] FIG. 5 is a schematic side view of a portion of another
embodiment of a catheter with a telescoping pullback section,
according to the invention;
[0021] FIG. 6A is a schematic side view of a portion of one
embodiment of a catheter with a pullback slider arrangement,
according to the invention;
[0022] FIG. 6B is a top view of the portion of the catheter of FIG.
6A, according to the invention;
[0023] FIG. 6C is a side cross-sectional view of the catheter of
FIG. 6A, according to the invention;
[0024] FIG. 7 is a schematic cross-sectional view of a portion of a
second embodiment of a catheter with a pullback slider arrangement
and a resistive sensor, according to the invention;
[0025] FIG. 8 is a schematic cross-sectional view of a portion of a
third embodiment of a catheter with a pullback slider arrangement
and a rotary resistive sensor, according to the invention;
[0026] FIG. 9 is a schematic cross-sectional view of a portion of a
fourth embodiment of a catheter with a pullback slider arrangement
and a capacitive sensor, according to the invention;
[0027] FIG. 10 is a schematic cross-sectional view of a portion of
a fifth embodiment of a catheter with a pullback slider arrangement
and an inductive sensor, according to the invention;
[0028] FIG. 11 is a schematic cross-sectional view of a portion of
a sixth embodiment of a catheter with a pullback slider arrangement
and a magnetic or optical sensor, according to the invention;
and
[0029] FIG. 12 is a schematic cross-sectional view of a portion of
a seventh embodiment of a catheter with a pullback slider
arrangement and a magnetic or optical sensor, according to the
invention.
DETAILED DESCRIPTION
[0030] The present invention is directed to the area of ultrasound
imaging systems and methods of making and using the systems. The
present invention is also directed to an ultrasound imaging system
and catheter that includes a manual pullback arrangement, as well
as methods of making and using the ultrasound systems and
catheters.
[0031] Suitable ultrasound imaging systems utilizing catheters
include, for example, intravascular ultrasound ("IVUS") and
intracardiac echocardiography ("ICE") systems. These systems may
include one or more transducers disposed on a distal end of a
catheter configured and arranged for percutaneous insertion into a
patient. Examples of IVUS imaging systems with catheters are found
in, for example, U.S. Pat. Nos. 6,945,938; 7,246,959; and
7,306,561; as well as U.S. Patent Application Publication Nos.
2006/0100522; 2006/0106320; 2006/0173350; 2006/0253028;
2007/0016054; and 2007/0038111; all of which are incorporated
herein by reference in their entireties.
[0032] In at least some embodiments, the imaging core may move
longitudinally (i.e., translate) along the blood vessel within
which the catheter is inserted to obtain a series of images along
the axial length of the blood vessel. In at least some embodiments,
during an imaging procedure the imaging core is retracted (i.e.,
pulled back) along the longitudinal length of the catheter. In many
conventional IVUS imaging systems this pullback procedure is
automated with a pullback arrangement coupled to a motor to pull
back the imaging core when directed by the clinician. It may be
desirable, however, to manually perform the pullback. An IVUS
catheter with an integrated pullback arrangement can be used for
manually performing a pullback procedure. In at least some
embodiments, the IVUS imaging system may also be capable of
performing an automated pullback procedure. In other embodiments,
the IVUS imaging system may only be capable of a manual pullback
procedure.
[0033] FIG. 1 illustrates an IVUS imaging system 100 having an IVUS
catheter 102 with an integrated pullback arrangement, a motordrive
104, and an imaging module 106. At least some of the components of
the IVUS imaging system 100 are placed near an operating table 108.
In at least some embodiments, the integrated pullback arrangement
of the IVUS catheter 102 is a manual pullback arrangement to allow
a clinician to manually control the pullback.
[0034] The imaging module 106 may include, for example, a processor
292, a pulse generator 290, and one or more displays 294, as
illustrated in FIG. 2. In at least some embodiments, the pulse
generator 290 generates electric signals that may be input to one
or more transducers (312 in FIG. 3) disposed in the catheter 102 so
that the one or more transducers generate acoustic signals for
imaging. In at least some embodiments, the processor 292 directs
the motordrive 104 (FIG. 1) to rotate an imaging core (306 in FIG.
3) disposed in the catheter 102.
[0035] In at least some embodiments, electrical signals transmitted
from the one or more transducers (312 in FIG. 3) and generated in
response to acoustic echoes may be input to the processor 292 for
processing. In at least some embodiments, the processed electrical
signals from the one or more transducers (312 in FIG. 3) may be
displayed as one or more images on the one or more displays 294. In
at least some embodiments, the processor 292 may also be used to
control the functioning of one or more of the other components of
the imaging module 106 or imaging system 100. For example, the
processor 292 may be used to control at least one of the frequency
or duration of the electrical signals transmitted from the pulse
generator 290, the rotation rate of the imaging core (306 in FIG.
3) by the motordrive 104, or one or more properties of one or more
images formed on the one or more displays 294.
[0036] FIG. 3 is a schematic perspective view of one embodiment of
the distal end 208 of the catheter 102. The catheter 102 includes a
sheath 302 having a distal portion 352 and a proximal portion (not
shown). The sheath 302 defines a lumen 304 extending along the
sheath. An imaging core 306 is disposed in the lumen 304. The
imaging core 306 includes an imaging device 308 coupled to a distal
end of a driveshaft 310.
[0037] The sheath 302 may be formed from any flexible,
biocompatible material suitable for insertion into a patient.
Examples of suitable materials include, for example, polyethylene,
polyurethane, plastic, spiral-cut stainless steel, nitinol
hypotube, and the like or combinations thereof.
[0038] One or more transducers 312 may be mounted to the imaging
device 308 and employed to transmit and receive acoustic signals.
In a preferred embodiment (as shown in FIG. 3), an array of
transducers 312 are mounted to the imaging device 308. In other
embodiments, a single transducer may be employed. In at least some
embodiments, multiple transducers in an irregular-array may be
employed. Any number of transducers 312 can be used. For example,
there can be one, two, three, four, five, six, seven, eight, nine,
ten, twelve, fifteen, sixteen, twenty, twenty-five, fifty, one
hundred, five hundred, one thousand, or more transducers. As will
be recognized, other numbers of transducers may also be used.
[0039] The one or more transducers 312 may be formed from one or
more known materials capable of transforming applied electrical
signals into pressure distortions on the surface of the one or more
transducers 312, and vice versa. Examples of suitable materials
include piezoelectric ceramic materials, piezocomposite materials,
piezoelectric plastics, barium titanates, lead zirconate titanates,
lead metaniobates, polyvinylidenefluorides, and the like.
[0040] The pressure distortions on the surface of the one or more
transducers 312 form acoustic signals of a frequency based on the
resonant frequencies of the one or more transducers 312. The
resonant frequencies of the one or more transducers 312 may be
affected by the size, shape, and material used to form the one or
more transducers 312. The one or more transducers 312 may be formed
in any shape suitable for positioning within the catheter 102 and
for propagating acoustic signals of a desired frequency in one or
more selected directions. For example, transducers may be
disc-shaped, block-shaped, rectangular-shaped, oval-shaped, and the
like. The one or more transducers may be formed in the desired
shape by any process including, for example, dicing, dice and fill,
machining, microfabrication, and the like.
[0041] In at least some embodiments, the one or more transducers
312 can be used to form a radial cross-sectional image of a
surrounding space. Thus, for example, when the one or more
transducers 312 are disposed in the catheter 102 and inserted into
a blood vessel of a patient, the one more transducers 312 may be
used to form a composite image of the walls of the blood vessel and
tissue surrounding the blood vessel by stitching together a
plurality of individual image frames.
[0042] The imaging core 306 is rotated about a longitudinal axis of
the catheter 102 while being disposed in the distal portion 352 of
the sheath 302. As the imaging core 306 rotates, the one or more
transducers 312 emit acoustic signal in different radial
directions. When an emitted acoustic signal with sufficient energy
encounters one or more medium boundaries, such as one or more
tissue boundaries, a portion of the emitted acoustic signal is
reflected back to the emitting transducer as an echo signal. Each
echo signal that reaches a transducer with sufficient energy to be
detected is transformed to an electrical signal in the receiving
transducer. The one or more transformed electrical signals are
transmitted to the imaging module (106 in FIG. 1) where the
processor 292 (FIG. 2) processes the electrical-signal
characteristics to generate a displayable image frame of the imaged
region based, at least in part, on a collection of information from
each of the acoustic signals transmitted and the echo signals
received.
[0043] In at least some embodiments, the rotation of the one or
more transducers 312 is driven by the motordrive 104 (FIG. 1) via
the driveshaft 310 extending along the catheter 102. The motordrive
104 is coupled to the proximal end of the catheter 102 and the
driveshaft 310 and rotates the driveshaft. Any suitable motordrive
104 can be used including those described in U.S. Pat. Nos.
6,004,271; 6,319,227; 6,413,222; 6,454,717; 6,475,224; and
6,517,528; and U.S. Patent Application Publication No.
2008/0167560, all of which are incorporated herein by reference in
their entireties. Another suitable motordrive is the MDU 5+
Motordrive from Boston Scientific Corporation (Natick, Mass.). It
will be recognized that some of these motordrives may also
incorporate automated pullback systems that may also be useful with
the manual pullback arrangement described herein to provide
clinicians with a choice between manual or automated pullback.
[0044] As the one or more transducers 312 rotate about the
longitudinal axis of the catheter 102 emitting acoustic signals, a
plurality of image frames are formed that collectively form a
composite radial cross-sectional image of a portion of the region
surrounding the one or more transducers 312, such as the walls of a
blood vessel of interest and the tissue surrounding the blood
vessel. In at least some embodiments, one or more of the image
frames can be displayed on the one or more displays 294 (FIG. 2).
In at least some embodiments, the radial cross-sectional composite
image can be displayed on the one or more displays 294 (FIG.
2).
[0045] The quality of imaging at different depths from the one or
more transducers 312 may be affected by one or more factors
including, for example, bandwidth, transducer focus, beam pattern,
as well as the frequency of the acoustic signal. The frequency of
the acoustic signal output from the one or more transducers 312 may
also affect the penetration depth of the acoustic signal output
from the one or more transducers 312. In general, as the frequency
of an acoustic signal is lowered, the depth of the penetration of
the acoustic signal within patient tissue increases. In at least
some embodiments, the IVUS imaging system 100 operates within a
frequency range of 5 MHz to 60 MHz.
[0046] One or more conductors 314 (for example, wires, cables,
traces, or the like) electrically couple the transducers 312 to the
imaging module 106 (FIG. 1). In at least some embodiments, the one
or more conductors 314 extend along the driveshaft 310.
[0047] The imaging device 308 is inserted in the lumen of the
catheter 102. In at least some embodiments, the catheter 102 (and
imaging device 308) may be inserted percutaneously into a patient
via an accessible blood vessel, such as the femoral artery or vein,
at a site remote from a target imaging location. The catheter 102
may then be advanced through patient vasculature to the target
imaging location, such as a portion of a selected blood vessel
(e.g., a peripheral blood vessel, a coronary blood vessel, or other
blood vessel), or one or more chambers of the patient's heart.
[0048] Returning to FIG. 1, the IVUS catheter 102 has a distal
section 110, a telescoping pullback section 112, and a proximal
extension 114. The distal section 110 includes the rotating imaging
core and a portion of the rotating driveshaft surrounded by a
stationary distal sheath. A portion of the distal section 110 is
the part of the IVUS catheter 102 that is inserted into the
patient. The proximal extension 114 includes a portion of the
rotating driveshaft and a stationary proximal sheath. The proximal
extension 114 of the catheter is coupled to the motordrive 104.
[0049] FIG. 4 illustrates a portion of one embodiment of an IVUS
catheter and integrated pullback arrangement. The telescoping
pullback section 112 is disposed between the distal section 110 and
the proximal extension 114 and makes use of a first telescope 120
sliding within a second telescope 122 to cause the rotating imaging
core to slide proximally or distally within the distal sheath. In
the illustrated embodiments, the first telescope 120 is distal to
the second telescope, but it will be understood that this
arrangement could be reversed with the first telescope proximal to
the second telescope. The driveshaft extends along the telescoping
pullback section 112 including through the first and second
telescopes 120, 122. It will be understood that the driveshaft can
be a single unitary structure or can include multiple elements that
are coupled together.
[0050] In at least some embodiments, one or both of the telescoping
pullback section 112 and distal section 110 can be flushed with
sterile saline via a port 124 disposed within the telescoping
section. In FIG. 4, the flush port 124 is depicted at the proximal
end of the second telescope 122, but it will be understood that the
port can be placed elsewhere along the telescoping pullback section
112 or distal section 110. The first and second telescopes 120, 122
join at a housing 126 which optionally contains a seal to allow the
telescoping action without leakage of the saline.
[0051] The telescoping pullback section 112 also includes a distal
grip 128 coupling one of the telescopes 120, 122 to the distal
sheath of the distal section 110 and a proximal grip 130 coupled to
the other of the telescopes 120, 122. During pullback, the distal
and proximal grips 128, 130 are gripped and moved away from each
other (for example, the distal grip 128 is held stationary while
the proximal grip 130 is pulled back). This action causes the
imaging device (e.g., one or more transducers) situated at the
distal tip of the imaging core to move in a proximal direction
within the distal section 110 to image successively more proximal
sections of the vascular anatomy. This arrangement allows for
manual pullback instead of the automated pullback of conventional
IVUS imaging systems.
[0052] The telescoping pullback section 112 of the catheter 102
also includes a sensor 136 capable of providing accurate pullback
position information to the imaging module 106 (FIG. 1). For
example, the sensor 136 can indicate a position of the first
telescope 120 relative to the second telescope 122. In the
embodiment of FIG. 4, the sensor 136 can be disposed, for example,
in the housing 126 or in the proximal grip 130. Any suitable sensor
136 can be used including, but not limited to, resistive,
capacitive, magnetic, optical or other sensors that can sense the
position of the first telescope 120 relative to the second
telescope 122 or sense the position of the one of the telescopes
120, 122 to a fixed position. Examples of sensors are described
below.
[0053] In the illustrated embodiment of FIG. 4, the sensor 136 can
observe stripes 138 on the first telescope 120. For example, these
stripes 138 may be alternating bands of dark and light pigment to
be read by an optical sensor or may be stripes of alternating
magnetically polarized material to be read by a magnetic sensor.
Communications between the sensor 136 and the proximal grip 130 are
made via an electrical cable or wire contiguous with the second
telescope 122. The cable or wire may be disposed alongside the
second telescope or may be embedded in the wall of the second
telescope or may be connected via some other path away from the
second telescope.
[0054] The proximal grip 130 may also incorporate one or more
control buttons 132, 134. The control buttons 132, 134 may be
operated during pullback to individually control a function such as
"imaging start/stop", "pullback recording start/stop", "zero
position", or "place bookmark".
[0055] Returning to FIG. 1, the proximal extension 114 includes a
portion of the rotating driveshaft and the conductor (for conveying
imaging signals between the imaging module and the ultrasound
transducers) surrounded by a stationary sheath. The proximal
extension 114 includes a connector to join it to the motordrive 104
and it may be larger in diameter than the distal portion 110 of the
catheter. In some embodiments, the proximal extension 114 also
supports a stationary (nonrotating) multi-conductor electrical
cable joined to the stationary sheath to convey signals from the
position sensor 136 (FIG. 4) and control buttons 132, 134 (FIG. 4)
to the imaging module 106.
[0056] FIG. 5 illustrates another embodiment of an IVUS catheter
with an integrated pullback sensor. In this embodiment, the
proximal grip 130 is disposed between the first telescope 120 and
the second telescope 122 and the flush port 124 is disposed between
the second telescope 122 and the proximal extension 114. The sensor
136 can be positioned within the proximal grip 130 (as illustrated)
or in the housing 126 that coupled the proximal grip 130 to the
first telescope 122.
[0057] FIGS. 6A-6C illustrate a portion of another embodiment of an
IVUS catheter 602 with an integrated pullback arrangement. In this
arrangement, the catheter includes a pullback slider arrangement
150 disposed between the distal section 110 and proximal extension
114 of the IVUS catheter. The proximal extension 114 includes a
proximal driveshaft 152 disposed within a proximal sheath 156. The
distal section 110 includes a distal driveshaft 154 disposed in a
distal sheath 158. The proximal and distal driveshafts 152, 154 are
coupled together. In the illustrated embodiment, the proximal and
distal driveshafts 152, 154 are coupled together within the
pullback slider arrangement 150 using an optional intermediate
driveshaft 153 (such as a hypotube).
[0058] The pullback slider arrangement 150 includes a housing 160
defining a slot 166 through the housing, a coupler 162 within the
housing, and a slider handle 164 attached to the coupler and
extending out of the housing. The coupler 162 is coupled to one or
both of the proximal or distal driveshafts 152, 154 to move the
driveshafts 152, 154 while still allowing the driveshafts 152, 154
to rotate within the coupler and housing 160. The coupler 162 may
be attached to the proximal sheath 156 as illustrated in FIG. 6C,
and may include bearings or other suitable components for coupling
to one or both of the driveshafts. By manually moving the slider
handle 164 along the slot 166 in the housing, the distal driveshaft
154 (and the imaging device attached to the distal end of the
driveshaft) is moved. A pullback procedure can be performed by
pulling the slider handle 164 along the slot 166 away from the
distal section 110 of the catheter.
[0059] In at least some embodiments, the distal section 110 can be
flushed with sterile saline via a port 124 on the pullback slider
arrangement 150 or distal section 110. The housing 160 which
optionally contains a seal 125 to allow flushing without leakage of
the saline.
[0060] The slider handle 164 or housing 160 may also incorporate
one or more control buttons 132, 134. The control buttons 132, 134
may be operated during pullback to individually control functions
such as "imaging start/stop", "pullback recording start/stop",
"zero position", or "place bookmark".
[0061] Pullback position measurement for the catheter 602 may be
accomplished using any suitable sensor and method of measurement.
It will also be understood the sensors and methods described below
can also be incorporated into the catheter 102 of FIGS. 4 and
5.
[0062] FIG. 7 illustrates one embodiment of a resistive sensor 136
used in a potentiometer configuration in which a voltage is
generated that is proportional to the coupler 162 position. This
can be accomplished using, for example, a slide potentiometer like
those used to control signal levels on, for example, an audio
mixing desk. The slide potentiometer 170 is actuated using the
coupler 162 and slider handle 164. Conductors 172 from the
potentiometer can be coupled to the imaging module 106 (FIG. 1) and
may be separate from the proximal extension 114 or run along or
within the sheath 156 of the proximal extension 114 or in any other
suitable arrangement.
[0063] FIG. 8 illustrates another embodiment of a resistive sensor
136 using a rotary potentiometer. The potentiometer is rotated
using a rack 174, a pinion 176, and one or more optional reduction
gears 178 to form a rotary potentiometer. Conductors 172 from the
potentiometer can be coupled to the imaging module 106 (FIG. 1) and
may be separate from the proximal extension 114 or run along or
within the sheath 156 of the proximal extension 114 or in any other
suitable arrangement.
[0064] In at least some embodiments, the potentiometer
configurations of FIGS. 7 and 8 use three wires to operate.
However, other resistive sensor can be used that measures a
resistance in proportion to position and would only use two
wires.
[0065] FIG. 9 illustrates one embodiment of a capacitive sensor 136
that includes a top plate 180 and a bottom plate 182 that overlap
over a distance defined by the position of the coupler 162 to form
a variable capacitor. Excess length of the top plate 180 is taken
up on a roller 184 (for example, a spring loaded or "windowshade"
roller). This configuration produces a capacitance that varies with
pullback position. Conductors 172 from the sensor can be coupled to
the imaging module 106 (FIG. 1) and may be separate from the
proximal extension 114 or run along or within the sheath 156 of the
proximal extension 114 or in any other suitable arrangement. Again,
as with the resistive sensor, a geared rotary variable capacitor
could also be used.
[0066] FIG. 10 illustrate one embodiment of an inductive sensor 136
that includes a coil 186 around a portion of the distal sheath 158
(FIG. 6C) with a highly magnetic material 188 embedded in a portion
of the rotating driveshaft 153, 154 (FIG. 6C) or a rotating sheath
(not shown) on the driveshaft. In this way, the inductance of coil
186 would vary as the magnetic material 188 is slid in or out of
the sheath 158. The inductance varies in a predictable way with the
overlap distance between the coil 186 and magnetic material 188.
Conductors 172 from the sensor can be coupled to the imaging module
106 (FIG. 1) and may be separate from the proximal extension 114 or
run along or within the sheath 156 of the proximal extension 114 or
in any other suitable arrangement. Again, as with the resistive
sensor, a geared rotary variable capacitor could also be used.
[0067] Capacitive and inductive sensors may be operated at some RF
frequency (for example, about 10 to 100 MHz) for purposes of
measuring their position-variable capacitance or inductance values.
In some alternative embodiments, it may be advantageous if the
ultrasound transmitting and receiving electronics are used to
interrogate the sensor. For example, a variable inductance sensor
could be coupled in parallel to a fixed capacitor and then the
combination placed in parallel with the transducer's RF
transmission line. If the resonant frequency of the sensor is
designed to be far from the transducer frequency (say, using a 10
MHz sensor with a 40 MHz transducer) then the sensor can be
interrogated by issuing a carefully designed transmit pulse between
imaging periods. The sensor inductance (and therefore the pullback
position) can be inferred from the resonant frequency of the LC
circuit. This configuration has an advantage that no additional
wiring may be needed for the pullback sensor instead of including
the conductors 172 illustrated in FIGS. 9 and 10. On the other
hand, such an arrangement may not be able to produce an accurate
position measurement without distorting the imaging signals.
[0068] FIG. 11 illustrates one embodiment of a magnetic or optical
sensor 136. In some embodiments, the sensor 136 is a magnetic
sensor (for example, a quadrature magneto-resistive sensor (such as
the MLS1000HD, available from Measurement Specialties, Inc./TE
Sensor Solutions of Middletown, Pa.)). The sensor 136 reads
magnetic stripes 138 manufactured with a well-defined pitch on a
strip 190 disposed in the housing 160. Alternatively, the sensor
136 is an optical sensor that reads black and white (or any other
differentiable colors) stripes 138 on the strip 190. A pair of such
sensors 136 (quadrature sensors) could be used to enable the
direction of position movement to be detected. As with the
resistive sensor, a geared rotary optical or magnetic sensor could
also be used. Conductors from the sensor 136 can be coupled to the
imaging module 106 (FIG. 1) and may be separate from the proximal
extension 114 or run along or within the sheath of the proximal
extension 114 or in any other suitable arrangement.
[0069] FIG. 12 illustrates another embodiment using a magnetic or
optical sensor 136. In this embodiment, a housing 160 is affixed to
the proximal extension 114. The proximal extension also contains
conductors 172 for the position sensor 136. The distal section 110
extends into a coupler 162 that also includes a seal and flush port
124 disposed extending out of a slot (not shown) in the housing
160. The coupler 162 also contains a strip 190 which is situated so
it can communicate with the position sensor 136 in the housing 160.
The sensor 136 can be a magnetic sensor that reads magnetic stripes
on the strip 190 or an optical sensor that reads black and white
(or any other differentiable colors) stripes on the strip 190.
[0070] The sensors 136 described above can be used to determine a
position of the imaging core during a pullback or other procedure
and can be used to align resulting imaging data. It will be
understood that the sensors 136 can also be used in conjunction
with an automated pullback device to also determine position of the
imaging core during an automated pullback procedure.
[0071] Pullback is performed by gripping the housing 160 in one
hand and the distal end of the coupler 162 in the other hand and
pulling back the coupler (or pushing forward the housing).
Alternatively, the flush port 124 may be used to slide the coupler
162 backwards.
[0072] Several of these embodiments illustrate one or more
conductors 172 coupling the sensor 136 to the imaging module 106
(FIG. 1) directly or via the motordrive 104 (FIG. 1) or the imaging
module 106 (FIG. 1). Alternatively or additionally, wireless
communication can be used between the imaging module 106 and the
sensor 136 using Bluetooth.TM. or other wireless technologies.
Alternatively or additionally, a wired connection may be provided
between the sensor 136 and the motordrive 104 with wireless
communication between the motordrive and the imaging module 106.
Similar methods of wired or wireless (or combination thereof)
communication can be used between the control buttons 132, 134 and
the imaging module 106. The housing 160 may also incorporate one or
more control buttons 132. The control buttons 132 may be operated
during pullback to individually control functions such as "imaging
start/stop", "pullback recording start/stop", "zero position", or
"place bookmark". It will be recognized that similar control
buttons can be used on any of the embodiments described above.
Moreover, it will be recognized that this embodiment can be
modified to use any of the other sensors described above.
[0073] As indicated above, the IVUS imaging system is capable of
recording multiple ultrasound frames while the imaging core is
pulled back inside the distal sheath. The resulting data set (a
longview data set) can represent a 3D view of a section of the
anatomy where the imaging catheter is disposed. In conventional
IVUS imaging systems, a longview data set is acquired using a
motorized pullback at a constant velocity (for example, about 0.5
or 1 mm/sec). IVUS frames are recorded at constant intervals (for
example, 30 frames/sec), so the frames may be positioned accurately
within the longview data set. Pullback velocities of 0.5 or 1
mm/sec, coupled with a frame capture rate of 30 frames/sec, produce
a longview resolution of 30 or 60 frames/mm.
[0074] For a manual pullback procedure, as described above, the
sensor can be used to determine correct frame positioning to
produce a longview data set regardless of pullback speed or
variability during the manual pullback procedure. In at least some
embodiments, an IVUS imaging system is configured to recognize a
"pullback" operation as different from a "push forward" operation
and IVUS frames are only acquired during a pullback procedure. Such
an arrangement may reduce or eliminate a problem of "backlash" in
the pullback system and facilitate correct position measurements.
If there were no backlash in the mechanical system, it can be
possible to record longview IVUS frames during pullback or push
forward.
[0075] One embodiment of a method for producing a longview data set
during a manual pullback procedure can include the following steps:
1. A control button (e.g., control buttons 132, 134 in FIG. 4, 5,
or 6B) is pressed on the catheter or imaging module, or a command
is issued, to the imaging module 106 to initiate a recording of
IVUS data (e.g., a longview recording.)
[0076] 2. The imaging core is pulled back (for example, at a
moderate to high speed, such as 10 to 30 mm/sec) and the system
acquires IVUS frames to produce a longview data set with relatively
low resolution (for example, 1 to 3 frames per mm with a frame
capture rate of 30 frames/sec). In at least some embodiments, the
clinician may stop pulling back and then pushes the imaging core
forward to revisit a region of interest (ROI) in the anatomy. The
system does not acquire IVUS frames during the push forward. In
some embodiments, the region of the pullback recording that has
been pushed back over may be colored or otherwise marked in the
IVUS display to denote that it may be overwritten during the next
pullback operation.
[0077] 3. After the imaging core is repositioned distal to the ROI,
manual pullback is resumed at, for example, a slower speed (such as
0.5 to 5 mm/sec) and the system recognizes that pullback has been
resumed and responds by reacquiring frames over the ROI. In at
least some embodiments, the longview data set is repainted over the
ROI at a greater longview resolution (about 6 to 60 frames/mm).
Acquisition may also be paused or restarted by pressing a control
button (e.g., control buttons 132, 134 in FIG. 4, 5, or 6B) on the
catheter or the imaging module. This feature allows reexamination
of portions of the anatomy without rerecording pullback data if so
desired.
[0078] 4. The IVUS imaging system is commanded to end the pullback
recording operation by pressing another control button (e.g.,
control buttons 132, 134 in FIG. 4, 5, or 6B) on the catheter or
the imaging module. The recorded pullback data set is then
available for review or archiving. The resulting longview data set
may contain regions with varying longview resolution (frames/mm).
The frames are correctly positioned along the longview axis because
accurate position data from the sensor were acquired along with the
IVUS frames.
[0079] The above specification, examples and data provide a
description of the manufacture and use of the composition of the
invention. Since many embodiments of the invention can be made
without departing from the spirit and scope of the invention, the
invention also resides in the claims hereinafter appended.
* * * * *