U.S. patent application number 17/478205 was filed with the patent office on 2022-01-06 for automated identification and classification of intravascular lesions.
The applicant listed for this patent is PHILIPS IMAGE GUIDED THERAPY CORPORATION. Invention is credited to Jacqueline KELLER, Fergus MERRITT, Andrew TOCHTERMAN.
Application Number | 20220000427 17/478205 |
Document ID | / |
Family ID | 1000005851158 |
Filed Date | 2022-01-06 |
United States Patent
Application |
20220000427 |
Kind Code |
A1 |
MERRITT; Fergus ; et
al. |
January 6, 2022 |
AUTOMATED IDENTIFICATION AND CLASSIFICATION OF INTRAVASCULAR
LESIONS
Abstract
Devices, systems, and methods of mapping a vessel system of a
patient and identifying lesions therein are disclosed. This
includes a method of evaluating a vessel of a patient, the method
comprising obtaining image data for the vessel of the patient,
obtaining physiological measurements for the vessel of the patient,
co-registering the obtained physiological measurements with the
obtained image data such that the physiological measurements are
associated with corresponding portions of the vessel of the
patient, analyzing the co-registered physiology measurements to
determine a classification of a lesion within the vessel of the
patient, and outputting, to a user interface, the classification of
the lesion. Other associated methods, systems, and devices are also
provided herein.
Inventors: |
MERRITT; Fergus; (ESCONDIDO,
CA) ; TOCHTERMAN; Andrew; (CARLSBAD, CA) ;
KELLER; Jacqueline; (SAN DIEGO, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
PHILIPS IMAGE GUIDED THERAPY CORPORATION |
SAN DIEGO |
CA |
US |
|
|
Family ID: |
1000005851158 |
Appl. No.: |
17/478205 |
Filed: |
September 17, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
14961656 |
Dec 7, 2015 |
11123019 |
|
|
17478205 |
|
|
|
|
62089090 |
Dec 8, 2014 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61B 5/02152 20130101;
G16H 20/40 20180101; A61B 5/7271 20130101; A61B 6/12 20130101; A61B
6/032 20130101; A61B 5/066 20130101; A61B 6/504 20130101; A61B
5/0215 20130101; A61B 5/02007 20130101; A61B 1/3137 20130101; A61B
5/7425 20130101; G16H 50/20 20180101; A61B 5/0073 20130101; G16H
30/40 20180101; A61B 8/0891 20130101; A61B 8/12 20130101; A61B
5/026 20130101 |
International
Class: |
A61B 5/00 20060101
A61B005/00; A61B 5/02 20060101 A61B005/02; A61B 5/0215 20060101
A61B005/0215; A61B 5/026 20060101 A61B005/026; A61B 5/06 20060101
A61B005/06; A61B 1/313 20060101 A61B001/313; G16H 20/40 20060101
G16H020/40; G16H 30/40 20060101 G16H030/40; G16H 50/20 20060101
G16H050/20 |
Claims
1. A system, comprising: a guidewire or catheter configured to be
positioned within a blood vessel of a patient, wherein the
guidewire or catheter comprises a pressure sensor configured to
acquire pressure measurements of the blood vessel, wherein the
pressure sensor is coupled to a distal portion of the guidewire or
catheter; and a processor configured for communication with a
display and the guidewire or catheter, wherein the processor is
configured to: communicate with an x-ray imaging device to obtain
an x-ray image of the blood vessel; control the guidewire or
catheter to acquire the pressure measurements via the pressure
sensor; determine, based on the pressure measurements, a plurality
of pressure ratios associated with a plurality of locations within
the blood vessel; co-register the plurality of pressure ratios with
the x-ray image such that each pressure ratio of the plurality of
pressure ratios is associated with a corresponding location of the
blood vessel; identify a position of a lesion within the blood
vessel based on the plurality of co-registered pressure ratios; and
output, to the display, a screen display comprising the x-ray image
and a graphical representation of the position of the lesion,
wherein the graphical representation is disposed at the position of
the lesion in the x-ray image.
2. The system of claim 1, wherein the position of the lesion spans
a length of the blood vessel, and wherein the graphical
representation spans the length of the blood vessel in the x-ray
image.
3. The system of claim 1, wherein the graphical representation is
overlaid on the blood vessel in the screen display.
4. The system of claim 1, wherein the processor is configured to:
receive a user input activating identification of the position of
the lesion; identify the position of the lesion in response to the
user input; and include the graphical representation in the screen
display in response to the user input.
5. The system of claim 4, wherein the screen display comprises an
activation status corresponding to identification of the position
of the lesion, wherein, in response to the user input, the screen
display comprises an on state for the activation status.
6. The system of claim 1, wherein the processor is configured to:
receive a user input deactivating identification of the position of
the lesion; and output the screen display without the graphical
representation.
7. The system of claim 6, wherein the screen display comprises an
activation status corresponding to identification of the position
of the lesion, wherein, in response to the user input, the screen
display comprises an off state for the activation status.
8. The system of claim 1, wherein the processor is configured to
identify the position of the lesion based on a change in the
plurality of co-registered pressure ratios between the plurality of
locations.
9. The system of claim 1, wherein the processor is configured to
analyze the x-ray image to identify an anatomical name for the
blood vessel, and wherein the screen display comprises the
anatomical name.
10. The system of claim 9, wherein the processor utilizes a
computer aided detection algorithm to identify the anatomical name
for the blood vessel.
11. The system of claim 1, wherein the x-ray image includes at
least one of a two-dimensional angiographic image, a
three-dimensional angiographic image, or a computed tomography
angiographic (CTA) image.
12. The system of claim 1, wherein the processor is configured to
determine a classification of the lesion, and wherein the screen
display comprises the classification.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application is continuation of U.S. patent
application Ser. No. 14/961,656, filed Dec. 7, 2015, now U.S. Pat.
No. 11,123,019, which claims priority to and the benefit of the
U.S. Provisional Patent Application No. 62/089,090, filed Dec. 8,
2014, which is hereby incorporated by reference in its
entirety.
TECHNICAL FIELD
[0002] The present disclosure relates generally to the assessment
of vessels for percutaneous coronary intervention (PCI) planning.
For example, some embodiments of the present disclosure are
configured to automatically label vessels of a patient in an image
and identify and/or classify lesions present within the vessels to
assist in diagnosing the. As a result, treatment options can
tailored to the specific characteristics of the patient's lesion(s)
and, thereby, improve the effectiveness of patient treatments.
BACKGROUND
[0003] Currently accepted techniques for assessing the severity of
a stenosis in a blood vessel include obtaining images and
physiological measurements of the vessel. For example, the severity
of a stenosis is sometimes observed visually and roughly estimated
based on user experience. For example, a patient's vasculature can
be visualized using angiography. However, even with experience and
expertise, the locations of stenoses in a vessel can be difficult
to visualize in a grayscale angiographic image. The use of pressure
data can improve the interpretation of information gleaned from an
angiogram. For example, fractional flow reserve (FFR) and/or
instantaneous wave-free ratio (iFR) can be utilized to estimate the
severity of a stenosis. FFR and iFR are calculations of the ratio
of a distal pressure measurement (taken on the distal side of the
stenosis) relative to a proximal pressure measurement (taken on the
proximal side of the stenosis). Both FFR and iFR provide an index
of stenosis severity that allows determination as to whether the
blockage significantly limits blood flow within the vessel to an
extent that treatment is required. Further, a more complete
diagnosis of the patient can be made by also performing
intravascular imaging, such as intravascular ultrasound (IVUS) or
optical coherence tomography (OCT). For example, in some instances
intravascular imaging can be utilized to provide a cross-sectional
image of the vessel and/or characterize the type(s) of
tissue/plaque present in a stenosis. Due to the variations and,
often, lack of clarity in angiographic and intravascular images,
these diagnostic techniques require extensive training and
experience before a user can confidently identify particular
vessels, let alone identify and classify lesions within those
vessels. However, the limited amount of time for training new
medical personnel results in many patients becoming de facto
training cases for the medical personnel, which can result in
misidentification of vessels, failure to identify significant
lesions, and/or misclassification of identified lesions. As a
result, the treatment plans selected for the patient may not be
optimized for the patient's actual medical needs.
[0004] Accordingly, there remains a need for improved devices,
systems, and methods for assessing the severity of a blockage in a
vessel and, in particular, a stenosis in a blood vessel. Moreover,
there remains a need for improved devices, systems, and methods of
automatically mapping vessel systems, identifying potential lesions
in the vessel system, and classifying the identified lesions in a
user friendly manner.
SUMMARY
[0005] Embodiments of the present disclosure are directed to
mapping a vessel system of a patient and identifying lesions
therein. One general aspect includes a method of evaluating a
vessel of a patient, the method comprising: obtaining image data
for the vessel of the patient; obtaining physiological measurements
for the vessel of the patient; co-registering the obtained
physiological measurements with the obtained image data such that
the physiological measurements are associated with corresponding
portions of the vessel of the patient; analyzing the co-registered
physiology measurements to determine a classification of a lesion
within the vessel of the patient; and outputting, to a user
interface, the classification of the lesion.
[0006] In one embodiment, the above method further comprises
analyzing the co-registered physiology measurements to determine a
location of the lesion within the vessel of the patient.
Furthermore, outputting the classification of the lesion to the
user interface may include overlaying a representation of the
classification onto an image of the vessel in proximity of the
location of the lesion. The method may further comprise analyzing
the obtained image data to identify a vessel name for the vessel
and outputting, to the user interface, the vessel name in proximity
to the vessel.
[0007] In an aspect, analyzing the obtained image data to identify
the vessel name for the vessel includes utilizing a computer aided
detection algorithm. The obtained image data may include image data
received from an extravascular imaging system. Furthermore, the
obtained image data may include at least one of a two-dimensional
angiographic image, a three-dimensional angiographic image, or a
computed tomography angiographic (CTA) image. The obtained
physiological measurements may include pressure measurements, and
at least some of the obtained pressure measurements may be obtained
at multiple locations along the vessel. The obtained physiological
measurements may also include flow measurements.
[0008] A system for evaluating a vessel of a patient is also
provided, the system comprising: a processing system in
communication with at least one intravascular device, the
processing system configured to: obtain image data for the vessel
of the patient; obtain physiological measurements for the vessel of
the patient; co-register the obtained physiological measurements
with the obtained image data such that the physiological
measurements are associated with corresponding portions of the
vessel of the patient; analyze the co-registered physiology
measurements to determine a classification of a lesion within the
vessel of the patient; and output, to a user interface, the
classification of the lesion.
[0009] In an aspect, the processing system is further configured to
analyze the co-registered physiology measurements to determine a
location of the lesion within the vessel of the patient.
Furthermore, the processing system may be configured to output the
classification of the lesion to the user interface by overlaying a
representation of the classification onto an image of the vessel in
proximity of the location of the lesion. The processing system may
be further configured to analyze the obtained image data to
identify a vessel name for the vessel and output, to the user
interface, the vessel name in proximity to the vessel.
[0010] In one embodiment, the processing system utilizes a computer
aided detection algorithm to identify the vessel name for the
vessel. Furthermore, the obtained image data may include image data
received from an extravascular imaging system, or at least one of a
two-dimensional angiographic image, a three-dimensional
angiographic image, or a computed tomography angiographic (CTA)
image. In an aspect, the at least one intravascular devices
includes a pressure-sensing intravascular device and wherein the
obtained physiological measurements include pressure measurements.
The processing system may be further configured to calculate a
pressure ratio based on the obtained pressure measurements. The at
least one intravascular devices may also include a flow-sensing
intravascular device and wherein the obtained physiological
measurements include flow measurements.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Illustrative embodiments of the present disclosure will be
described with reference to the accompanying drawings, of
which:
[0012] FIG. 1 is a diagrammatic perspective view of a vessel having
a stenosis according to an embodiment of the present
disclosure.
[0013] FIG. 2 is a diagrammatic, partial cross-sectional
perspective view of a portion of the vessel of FIG. 1 taken along
section line 2-2 of FIG. 1.
[0014] FIG. 3 is a diagrammatic, partial cross-sectional
perspective view of the vessel of FIGS. 1 and 2 with instruments
positioned therein according to an embodiment of the present
disclosure.
[0015] FIG. 4 is a diagrammatic, schematic view of a system
according to an embodiment of the present disclosure.
[0016] FIG. 5 is a stylized image of a patient's vasculature as
seen in an angiogram image on a user interface according to an
embodiment of the present disclosure.
[0017] FIG. 6 is an annotated version of a patient's vasculature as
seen in an angiogram image on a user interface according to an
embodiment of the present disclosure.
[0018] FIG. 7 is an annotated version of a patient's vasculature as
seen in an angiogram image on a user interface according to another
embodiment of the present disclosure.
[0019] FIG. 8 is an annotated version of a patient's vasculature as
seen in an angiogram image on a user interface according to another
embodiment of the present disclosure
[0020] FIG. 9 is a graphical user interface screen display
according to an embodiment of the present disclosure.
[0021] FIG. 10 is a series of stylized images of a vessel
illustrating classification of vessel obstructions according to an
embodiment of the present disclosure.
[0022] FIG. 11 is a flow diagram of a method for identify and
classifying lesions with an vessel system according to an
embodiment of the present disclosure.
[0023] These drawings may be better understood by reference to the
following detailed description.
DETAILED DESCRIPTION
[0024] For the purposes of promoting an understanding of the
principles of the present disclosure, reference will now be made to
the embodiments illustrated in the drawings, and specific language
will be used to describe the same. It is nevertheless understood
that no limitation to the scope of the disclosure is intended. Any
alterations and further modifications to the described devices,
systems, and methods, and any further application of the principles
of the present disclosure are fully contemplated and included
within the present disclosure as would normally occur to one
skilled in the art to which the disclosure relates. In particular,
it is fully contemplated that the features, components, and/or
steps described with respect to one embodiment may be combined with
the features, components, and/or steps described with respect to
other embodiments of the present disclosure. For the sake of
brevity, however, the numerous iterations of these combinations
will not be described separately.
[0025] Physiological measurement data and the coronary angiogram
typically behave as complementary, yet segregated sources of
information. The coronary angiogram has been used to make treatment
decisions. More recently, physiological data (including, but not
limited to, pressure and/or flow measurements, both at hyperemia
and rest) have shown that better decisions can be made based on the
severity of a blockage by measuring the change in underlying
physiological conditions from the beginning of a target artery to
the end. Treating a patient based on the severity of this change or
delta has shown to improve outcomes and reduce waste from
unnecessary procedures. In one or more aspects of the present
disclosure, the physiological data, as collected real-time, is
linked or co-registered to a schematic of the coronary arteries or
an angiogram. At this point, a computer aided detection algorithm
can be applied to the data to identify and map coronary vessels.
Physiological measurements obtained from within the vessels can
then be compared to the map to identify lesion locations. Further,
the physiological measurements can be utilized to determine a
length and/or classify the identified lesions. In making the
classification, data representing the lesion sites may also be
visually depicted in a way that allows a clinician to interact and
assess the severity and/or boundaries of the lesion. Furthermore,
the identification and classification of the lesions in the vessel
system can be displayed to a clinician on a user interface. Among
other benefits, the identification and classification of the
lesions can permit a clinician to plan a percutaneous coronary
intervention tailored to the specific lesion characteristics of the
patient.
[0026] Referring to FIGS. 1 and 2, shown therein is a vessel 100
having a stenosis according to an embodiment of the present
disclosure. In that regard, FIG. 1 is a diagrammatic perspective
view of the vessel 100, while FIG. 2 is a partial cross-sectional
perspective view of a portion of the vessel 100 taken along section
line 2-2 of FIG. 1. Referring more specifically to FIG. 1, the
vessel 100 includes a proximal portion 102 and a distal portion
104. A lumen 106 extends along the length of the vessel 100 between
the proximal portion 102 and the distal portion 104. In that
regard, the lumen 106 is configured to allow the flow of fluid
through the vessel. In some instances, the vessel 100 is a blood
vessel. In some particular instances, the vessel 100 is a coronary
artery. In such instances, the lumen 106 is configured to
facilitate the flow of blood through the vessel 100.
[0027] As shown, the vessel 100 includes a stenosis 108 between the
proximal portion 102 and the distal portion 104. Stenosis 108 is
generally representative of any blockage or other structural
arrangement that results in a restriction to the flow of fluid
through the lumen 106 of the vessel 100. Embodiments of the present
disclosure are suitable for use in a wide variety of vascular
applications, including without limitation coronary, peripheral
(including but not limited to lower limb, carotid, and
neurovascular), renal, and/or venous. Where the vessel 100 is a
blood vessel, the stenosis 108 may be a result of plaque buildup,
including without limitation plaque components such as fibrous,
fibro-lipidic (fibro fatty), necrotic core, calcified (dense
calcium), blood, fresh thrombus, and mature thrombus. Generally,
the composition of the stenosis will depend on the type of vessel
being evaluated. In that regard, it is understood that the concepts
of the present disclosure are applicable to virtually any type of
blockage or other narrowing of a vessel that results in decreased
fluid flow.
[0028] Referring more particularly to FIG. 2, the lumen 106 of the
vessel 100 has a diameter 110 proximal of the stenosis 108 and a
diameter 112 distal of the stenosis. In some instances, the
diameters 110 and 112 are substantially equal to one another. In
that regard, the diameters 110 and 112 are intended to represent
healthy portions, or at least healthier portions, of the lumen 106
in comparison to stenosis 108. Accordingly, these healthier
portions of the lumen 106 are illustrated as having a substantially
constant cylindrical profile and, as a result, the height or width
of the lumen has been referred to as a diameter. However, it is
understood that in many instances these portions of the lumen 106
will also have plaque buildup, a non-symmetric profile, and/or
other irregularities, but to a lesser extent than stenosis 108 and,
therefore, will not have a cylindrical profile. In such instances,
the diameters 110 and 112 are understood to be representative of a
relative size or cross-sectional area of the lumen and do not imply
a circular cross-sectional profile.
[0029] As shown in FIG. 2, stenosis 108 includes plaque buildup 114
that narrows the lumen 106 of the vessel 100. In some instances,
the plaque buildup 114 does not have a uniform or symmetrical
profile, making angiographic evaluation of such a stenosis
unreliable. In the illustrated embodiment, the plaque buildup 114
includes an upper portion 116 and an opposing lower portion 118. In
that regard, the lower portion 118 has an increased thickness
relative to the upper portion 116 that results in a non-symmetrical
and non-uniform profile relative to the portions of the lumen
proximal and distal of the stenosis 108. As shown, the plaque
buildup 114 decreases the available space for fluid to flow through
the lumen 106. In particular, the cross-sectional area of the lumen
106 is decreased by the plaque buildup 114. At the narrowest point
between the upper and lower portions 116, 118 the lumen 106 has a
height 120, which is representative of a reduced size or
cross-sectional area relative to the diameters 110 and 112 proximal
and distal of the stenosis 108. Note that the stenosis 108,
including plaque buildup 114 is exemplary in nature and should be
considered limiting in any way. In that regard, it is understood
that the stenosis 108 has other shapes and/or compositions that
limit the flow of fluid through the lumen 106 in other instances.
While the vessel 100 is illustrated in FIGS. 1 and 2 as having a
single stenosis 108 and the description of the embodiments below is
primarily made in the context of a single stenosis, it is
nevertheless understood that the devices, systems, and methods
described herein have similar application for a vessel having
multiple stenosis regions.
[0030] Referring now to FIG. 3, the vessel 100 is shown with
instruments 130 and 132 positioned therein according to an
embodiment of the present disclosure. In general, instruments 130
and 132 may be any form of device, instrument, or probe sized and
shaped to be positioned within a vessel. In the illustrated
embodiment, instrument 130 is generally representative of a guide
wire, while instrument 132 is generally representative of a
catheter. In that regard, instrument 130 extends through a central
lumen of instrument 132. However, in other embodiments, the
instruments 130 and 132 take other forms. In that regard, the
instruments 130 and 132 are of similar form in some embodiments.
For example, in some instances, both instruments 130 and 132 are
guide wires. In other instances, both instruments 130 and 132 are
catheters. On the other hand, the instruments 130 and 132 are of
different form in some embodiments, such as the illustrated
embodiment, where one of the instruments is a catheter and the
other is a guide wire. Further, in some instances, the instruments
130 and 132 are disposed coaxial with one another, as shown in the
illustrated embodiment of FIG. 3. In other instances, one of the
instruments extends through an off-center lumen of the other
instrument. In yet other instances, the instruments 130 and 132
extend side-by-side. In some particular embodiments, at least one
of the instruments is as a rapid-exchange device, such as a
rapid-exchange catheter. In such embodiments, the other instrument
is a buddy wire or other device configured to facilitate the
introduction and removal of the rapid-exchange device. Further
still, in other instances, instead of two separate instruments 130
and 132 a single instrument is utilized. In some embodiments, the
single instrument incorporates aspects of the functionalities
(e.g., data acquisition) of both instruments 130 and 132.
[0031] Instrument 130 is configured to obtain diagnostic
information about the vessel 100. In that regard, the instrument
130 includes one or more sensors, transducers, and/or other
monitoring elements configured to obtain the diagnostic information
about the vessel. The diagnostic information includes one or more
of pressure, flow (velocity and/or volume), images (including
images obtained using ultrasound (e.g., IVUS), OCT, thermal, and/or
other imaging techniques), temperature, and/or combinations
thereof. The one or more sensors, transducers, and/or other
monitoring elements are positioned adjacent a distal portion of the
instrument 130 in some instances. In that regard, the one or more
sensors, transducers, and/or other monitoring elements are
positioned less than 30 cm, less than 10 cm, less than 5 cm, less
than 3 cm, less than 2 cm, and/or less than 1 cm from a distal tip
134 of the instrument 130 in some instances. In some instances, at
least one of the one or more sensors, transducers, and/or other
monitoring elements is positioned at the distal tip of the
instrument 130.
[0032] The instrument 130 can include at least one element
configured to monitor pressure within the vessel 100. The pressure
monitoring element can take the form a piezo-resistive pressure
sensor, a piezo-electric pressure sensor, a capacitive pressure
sensor, an electromagnetic pressure sensor, a fluid column (the
fluid column being in communication with a fluid column sensor that
is separate from the instrument and/or positioned at a portion of
the instrument proximal of the fluid column), an optical pressure
sensor, and/or combinations thereof. In some instances, one or more
features of the pressure monitoring element are implemented as a
solid-state component manufactured using semiconductor and/or other
suitable manufacturing techniques. Examples of commercially
available guide wire products that include suitable pressure
monitoring elements include, without limitation, the Verrata.RTM.
pressure guide wire, the PrimeWire Prestige.RTM. PLUS pressure
guide wire, and the ComboWire.RTM. XT pressure and flow guide wire,
each available from Volcano Corporation, as well as the
PressureWire' Certus guide wire and the PressureWire.TM. Aeris
guide wire, each available from St. Jude Medical, Inc. Generally,
the instrument 130 is sized such that it can be positioned through
the stenosis 108 without significantly impacting fluid flow across
the stenosis, which would impact the distal pressure reading.
Accordingly, in some instances the instrument 130 has an outer
diameter of 0.018'' or less. In some embodiments, the instrument
130 has an outer diameter of 0.014'' or less. In some embodiments,
the instrument 130 has an outer diameter of 0.035'' or less.
[0033] Instrument 132 is also configured to obtain diagnostic
information about the vessel 100. In some instances, instrument 132
is configured to obtain the same diagnostic information as
instrument 130. In other instances, instrument 132 is configured to
obtain different diagnostic information than instrument 130, which
may include additional diagnostic information, less diagnostic
information, and/or alternative diagnostic information. The
diagnostic information obtained by instrument 132 includes one or
more of pressure, flow (velocity and/or volume), images (including
images obtained using ultrasound (e.g., IVUS), OCT, thermal, and/or
other imaging techniques), temperature, and/or combinations
thereof. Instrument 132 includes one or more sensors, transducers,
and/or other monitoring elements configured to obtain this
diagnostic information. In that regard, the one or more sensors,
transducers, and/or other monitoring elements are positioned
adjacent a distal portion of the instrument 132 in some instances.
In that regard, the one or more sensors, transducers, and/or other
monitoring elements are positioned less than 30 cm, less than 10
cm, less than 5 cm, less than 3 cm, less than 2 cm, and/or less
than 1 cm from a distal tip 136 of the instrument 132 in some
instances. In some instances, at least one of the one or more
sensors, transducers, and/or other monitoring elements is
positioned at the distal tip of the instrument 132.
[0034] Similar to instrument 130, instrument 132 can also include
at least one element configured to monitor pressure within the
vessel 100. The pressure monitoring element can take the form a
piezo-resistive pressure sensor, a piezo-electric pressure sensor,
a capacitive pressure sensor, an electromagnetic pressure sensor, a
fluid column (the fluid column being in communication with a fluid
column sensor that is separate from the instrument and/or
positioned at a portion of the instrument proximal of the fluid
column), an optical pressure sensor, and/or combinations thereof.
In some instances, one or more features of the pressure monitoring
element are implemented as a solid-state component manufactured
using semiconductor and/or other suitable manufacturing techniques.
Currently available catheter products suitable for use with one or
more of Siemens AXIOM Sensis, Mennen Horizon XVu, and Philips Xper
IM Physiomonitoring 5 and include pressure monitoring elements can
be utilized for instrument 132 in some instances.
[0035] In accordance with aspects of the present disclosure, at
least one of the instruments 130 and 132 is configured to monitor a
pressure within the vessel 100 distal of the stenosis 108 and at
least one of the instruments 130 and 132 is configured to monitor a
pressure within the vessel proximal of the stenosis. In that
regard, the instruments 130, 132 are sized and shaped to allow
positioning of the at least one element configured to monitor
pressure within the vessel 100 to be positioned proximal and/or
distal of the stenosis 108 as necessary based on the configuration
of the devices. In that regard, FIG. 3 illustrates a position 138
suitable for measuring pressure distal of the stenosis 108. In that
regard, the position 138 is less than 5 cm, less than 3 cm, less
than 2 cm, less than 1 cm, less than 5 mm, and/or less than 2.5 mm
from the distal end of the stenosis 108 (as shown in FIG. 2) in
some instances. FIG. 3 also illustrates a plurality of suitable
positions for measuring pressure proximal of the stenosis 108. In
that regard, positions 140, 142, 144, 146, and 148 each represent a
position that is suitable for monitoring the pressure proximal of
the stenosis in some instances. In that regard, the positions 140,
142, 144, 146, and 148 are positioned at varying distances from the
proximal end of the stenosis 108 ranging from more than 20 cm down
to about 5 mm or less. Generally, the proximal pressure measurement
will be spaced from the proximal end of the stenosis. Accordingly,
in some instances, the proximal pressure measurement is taken at a
distance equal to or greater than an inner diameter of the lumen of
the vessel from the proximal end of the stenosis. In the context of
coronary artery pressure measurements, the proximal pressure
measurement is generally taken at a position proximal of the
stenosis and distal of the aorta, within a proximal portion of the
vessel. However, in some particular instances of coronary artery
pressure measurements, the proximal pressure measurement is taken
from a location inside the aorta. In other instances, the proximal
pressure measurement is taken at the root or ostium of the coronary
artery.
[0036] In some embodiments, at least one of the instruments 130 and
132 is configured to monitor pressure within the vessel 100 while
being moved through the lumen 106. In some instances, instrument
130 is configured to be moved through the lumen 106 and across the
stenosis 108. In that regard, the instrument 130 is positioned
distal of the stenosis 108 and moved proximally (i.e., pulled back)
across the stenosis to a position proximal of the stenosis in some
instances. In other instances, the instrument 130 is positioned
proximal of the stenosis 108 and moved distally across the stenosis
to a position distal of the stenosis. Movement of the instrument
130, either proximally or distally, is controlled manually by
medical personnel (e.g., hand of a surgeon) in some embodiments. In
other embodiments, movement of the instrument 130, either
proximally or distally, is controlled automatically by a movement
control device (e.g., a pullback device, such as the Trak Back.RTM.
II Device available from Volcano Corporation). In that regard, the
movement control device controls the movement of the instrument 130
at a selectable and known speed (e.g., 2.0 mm/s, 1.0 mm/s, 0.5
mm/s, 0.2 mm/s, etc.) in some instances. Movement of the instrument
130 through the vessel is continuous for each pullback or push
through, in some instances. In other instances, the instrument 130
is moved step-wise through the vessel (i.e., repeatedly moved a
fixed amount of distance and/or a fixed amount of time). Some
aspects of the visual depictions discussed below are particularly
suited for embodiments where at least one of the instruments 130
and 132 is moved through the lumen 106. Further, in some particular
instances, aspects of the visual depictions discussed below are
particularly suited for embodiments where a single instrument is
moved through the lumen 106, with or without the presence of a
second instrument.
[0037] The instruments 130 and/or 132 can be used to conduct
medical sensing procedures associated with Instant Wave-Free
Ratio.TM. Functionality (iFR.RTM. Functionality) (both trademarks
of Volcano Corp.) and those disclosed in U.S. patent application
Ser. No. 13/460,296, entitled "DEVICES, SYSTEMS, AND METHODS FOR
ASSESSING A VESSEL," hereby incorporated by reference in its
entirety, which discloses the use of pressure ratios that are
available without application of a hyperemic agent. Further,
medical sensing procedures associated with compensated Pd/Pa ratios
suitable for estimating iFR.RTM., FFR, and/or other accepted
diagnostic pressure ratios as disclosed in U.S. Provisional Patent
Application No. 62/024,005, filed Jul. 14, 2014 and entitled
"DEVICES, SYSTEMS, AND METHODS FOR TREATMENT OF VESSELS," which is
hereby incorporated by reference in its entirety, can be conducted
using the instruments 130 and/or 132.
[0038] Referring now to FIG. 4, shown therein is a system 150
according to an embodiment of the present disclosure. In that
regard, FIG. 4 is a diagrammatic, schematic view of the system 150.
As shown, the system 150 includes an instrument 152. In that
regard, in some instances instrument 152 is suitable for use as at
least one of instruments 130 and 132 discussed above. Accordingly,
in some instances the instrument 152 includes features similar to
those discussed above with respect to instruments 130 and 132 in
some instances. In the illustrated embodiment, the instrument 152
is a guide wire having a distal portion 154 and a housing 156
positioned adjacent the distal portion. In that regard, the housing
156 is spaced approximately 3 cm from a distal tip of the
instrument 152. The housing 156 is configured to house one or more
sensors, transducers, and/or other monitoring elements configured
to obtain the diagnostic information about the vessel. In the
illustrated embodiment, the housing 156 contains at least a
pressure sensor configured to monitor a pressure within a lumen in
which the instrument 152 is positioned. A shaft 158 extends
proximally from the housing 156. A torque device 160 is positioned
over and coupled to a proximal portion of the shaft 158. A proximal
end portion 162 of the instrument 152 is coupled to a connector
164. A cable 166 extends from connector 164 to a connector 168. In
some instances, connector 168 is configured to be plugged into an
interface 170. In that regard, interface 170 is a patient interface
module (PIM) in some instances. In some instances, the cable 166 is
replaced with a wireless connection. In that regard, it is
understood that various communication pathways between the
instrument 152 and the interface 170 may be utilized, including
physical connections (including electrical, optical, and/or fluid
connections), wireless connections, and/or combinations
thereof.
[0039] The interface 170 is communicatively coupled to a computing
device 172 via a connection 174. Computing device 172 is generally
representative of any device suitable for performing the processing
and analysis techniques discussed within the present disclosure. In
some embodiments, the computing device 172 includes a processor,
random access memory, and a storage medium. In that regard, in some
particular instances the computing device 172 is programmed to
execute steps associated with the data acquisition and analysis
described herein. Accordingly, it is understood that any steps
related to data acquisition, data processing, instrument control,
and/or other processing or control aspects of the present
disclosure may be implemented by the computing device using
corresponding instructions stored on or in a non-transitory
computer readable medium accessible by the computing device. In
some instances, the computing device 172 is a console device. In
some particular instances, the computing device 172 is similar to
the s5 Imaging System or the s5i Imaging System, each available
from Volcano Corporation. In some instances, the computing device
172 is portable (e.g., handheld, on a rolling cart, etc.). In some
instances, all or a portion of the computing device 172 can be
implemented as a bedside controller such that one or more
processing steps described herein can be performed by processing
component(s) of the bedside controller. An exemplary bedside
controller is described in U.S. Provisional Application No.
62/049,265, titled "Bedside Controller for Assessment of Vessels
and Associated Devices, Systems, and Methods," and filed Sep. 11,
2014, the entirety of which is hereby incorporated by reference
herein. Further, it is understood that in some instances the
computing device 172 comprises a plurality of computing devices. In
that regard, it is particularly understood that the different
processing and/or control aspects of the present disclosure may be
implemented separately or within predefined groupings using a
plurality of computing devices. Any divisions and/or combinations
of the processing and/or control aspects described below across
multiple computing devices are within the scope of the present
disclosure.
[0040] Together, connector 164, cable 166, connector 168, interface
170, and connection 174 facilitate communication between the one or
more sensors, transducers, and/or other monitoring elements of the
instrument 152 and the computing device 172. However, this
communication pathway is exemplary in nature and should not be
considered limiting in any way. In that regard, it is understood
that any communication pathway between the instrument 152 and the
computing device 172 may be utilized, including physical
connections (including electrical, optical, and/or fluid
connections), wireless connections, and/or combinations thereof. In
that regard, it is understood that the connection 174 is wireless
in some instances. In some instances, the connection 174 includes a
communication link over a network (e.g., intranet, internet,
telecommunications network, and/or other network). In that regard,
it is understood that the computing device 172 is positioned remote
from an operating area where the instrument 152 is being used in
some instances. Having the connection 174 include a connection over
a network can facilitate communication between the instrument 152
and the remote computing device 172 regardless of whether the
computing device is in an adjacent room, an adjacent building, or
in a different state/country. Further, it is understood that the
communication pathway between the instrument 152 and the computing
device 172 is a secure connection in some instances. Further still,
it is understood that, in some instances, the data communicated
over one or more portions of the communication pathway between the
instrument 152 and the computing device 172 is encrypted.
[0041] The system 150 also includes an instrument 175. In that
regard, in some instances instrument 175 is suitable for use as at
least one of instruments 130 and 132 discussed above. Accordingly,
in some instances the instrument 175 includes features similar to
those discussed above with respect to instruments 130 and 132 in
some instances. In the illustrated embodiment, the instrument 175
is a catheter-type device. In that regard, the instrument 175
includes one or more sensors, transducers, and/or other monitoring
elements adjacent a distal portion of the instrument configured to
obtain the diagnostic information about the vessel. In the
illustrated embodiment, the instrument 175 includes a pressure
sensor configured to monitor a pressure within a lumen in which the
instrument 175 is positioned. The instrument 175 is in
communication with an interface 176 via connection 177. In some
instances, interface 176 is a hemodynamic monitoring system or
other control device, such as Siemens AXIOM Sensis, Mennen Horizon
XVu, and Philips Xper IM Physiomonitoring 5. In one particular
embodiment, instrument 175 is a pressure-sensing catheter that
includes fluid column extending along its length. In such an
embodiment, interface 176 includes a hemostasis valve fluidly
coupled to the fluid column of the catheter, a manifold fluidly
coupled to the hemostasis valve, and tubing extending between the
components as necessary to fluidly couple the components. In that
regard, the fluid column of the catheter is in fluid communication
with a pressure sensor via the valve, manifold, and tubing. In some
instances, the pressure sensor is part of interface 176. In other
instances, the pressure sensor is a separate component positioned
between the instrument 175 and the interface 176. The interface 176
is communicatively coupled to the computing device 172 via a
connection 178.
[0042] The computing device 172 is communicatively coupled to a
display device 180 via a connection 182. In some embodiments, the
display device 172 is a component of the computing device 172,
while in other embodiments, the display device 172 is distinct from
the computing device 172. In some embodiments, the display device
172 is implemented as a bedside controller having a touch-screen
display as described, for example, in U.S. Provisional Application
No. 62/049,265, titled "Bedside Controller for Assessment of
Vessels and Associated Devices, Systems, and Methods," and filed
Sep. 11, 2014, the entirety of which is hereby incorporated by
reference herein. The computing device 172 can generate screen
displays including data collected by the instruments 152 and 175
and other instruments, quantities computed based on the collected
data, visualizations of the vessel in which the data is collected,
and visualizations based on the collected data and computed
quantities. Exemplary screen displays are illustrated in FIGS. 5
and 7. The computing device 172 can provide the display data
associated with the screen displays to the display device 180.
[0043] The computing device 172 can additionally be communicatively
coupled to a user interface device. The user interface device
permits a user to interact with the screen displays on the display
device 180. For example, the user can provide a user input to
modify all or a portion of the screen display using the user
interface device. Exemplary user inputs and the corresponding
modifications to the screen display are illustrated in FIGS. 5 and
7. In some embodiments, the user interface device is a separate
component from the display device 180. In other embodiments, the
user interface device is part of the display device 180. For
example, the user interface device can be implemented as a bedside
controller having a touch-screen display as described, for example,
in U.S. Provisional Application No. 62/049,265, titled "Bedside
Controller for Assessment of Vessels and Associated Devices,
Systems, and Methods," and filed Sep. 11, 2014, the entirety of
which is hereby incorporated by reference herein. In such
embodiments, a user input can be a touch input received on the
touch sensitive display of the bedside controller.
[0044] Similar to the connections between instrument 152 and the
computing device 172, interface 176 and connections 177 and 178
facilitate communication between the one or more sensors,
transducers, and/or other monitoring elements of the instrument 175
and the computing device 172. However, this communication pathway
is exemplary in nature and should not be considered limiting in any
way. In that regard, it is understood that any communication
pathway between the instrument 175 and the computing device 172 may
be utilized, including physical connections (including electrical,
optical, and/or fluid connections), wireless connections, and/or
combinations thereof. In that regard, it is understood that the
connection 178 is wireless in some instances. In some instances,
the connection 178 includes a communication link over a network
(e.g., intranet, internet, telecommunications network, and/or other
network). In that regard, it is understood that the computing
device 172 is positioned remote from an operating area where the
instrument 175 is being used in some instances. Having the
connection 178 include a connection over a network can facilitate
communication between the instrument 175 and the remote computing
device 172 regardless of whether the computing device is in an
adjacent room, an adjacent building, or in a different
state/country. Further, it is understood that the communication
pathway between the instrument 175 and the computing device 172 is
a secure connection in some instances. Further still, it is
understood that, in some instances, the data communicated over one
or more portions of the communication pathway between the
instrument 175 and the computing device 172 is encrypted.
[0045] It is understood that one or more components of the system
150 are not included, are implemented in a different
arrangement/order, and/or are replaced with an alternative
device/mechanism in other embodiments of the present disclosure.
For example, in some instances, the system 150 does not include
interface 170 and/or interface 176. In such instances, the
connector 168 (or other similar connector in communication with
instrument 152 or instrument 175) may plug into a port associated
with computing device 172. Alternatively, the instruments 152, 175
may communicate wirelessly with the computing device 172. Generally
speaking, the communication pathway between either or both of the
instruments 152, 175 and the computing device 172 may have no
intermediate nodes (i.e., a direct connection), one intermediate
node between the instrument and the computing device, or a
plurality of intermediate nodes between the instrument and the
computing device.
[0046] In some embodiments, the system 150 can additionally include
a bedside controller, such as the bedside controller described in
U.S. Provisional Application No. 62/049,265, titled "Bedside
Controller for Assessment of Vessels and Associated Devices,
Systems, and Methods," and filed Sep. 11, 2014, the entirety of
which is hereby incorporated by reference herein. The bedside
controller may be utilized by a clinician to control instruments
152 and 175 to acquire pressure data during a procedure, watch
real-time medical pressure measurements (e.g., visual
representations of pressure data, such as pressure waveforms,
numerical values, etc.), compute pressure ratio(s) based on the
collected pressure data, and interact with the obtained medical
sensing data, a visual representation of the obtained medical
sensing data and/or computed pressure ratio(s), a visualization
based on the obtained medical sensing data and/or computed pressure
ratio(s), and/or a visual representation of the vessel 100. In that
regard, the bedside controller can be communicatively coupled to
the computing device 172, the interfaces 170 and 176, and/or the
instruments 152 and 175.
[0047] In some embodiments, the system 150 can include an inventory
database 190 associated with a clinical environment, such as a
hospital or other healthcare facility at which a PCI would be
carried out on a patient. The inventory database can store various
data about stents that are available to a clinician for use. The
data can include manufacturer names, length, diameter, material,
quantity available at the hospital, quantity available for
immediate use, resupply frequency, next shipment date, and other
suitable information. The computing device 172 can compile a
plurality of stent options based on the inventory database 190 and
provide a selection menu to the clinician. The computing device 172
can provide automatically recommend a particular stent (e.g., a
stent from a particular manufacturer, with a particular length,
diameter, and/or material) based on the PCI planning conducted
using the graphical user interface. The computing device 172 can
also receive a user input selecting a particular stent and provide
it into the graphical user interface such that a clinician can
assess the efficacy of treatment using the selected stent. The
computing device 172 is communicatively coupled to the inventory
database 190 via a connection 192. The connection 192 can be
representative of one or more network connections that
communicatively couple the computing device 172 with a computing
system of the healthcare facility.
[0048] The diagnostic information and/or data obtained by
instruments 130, 132, 152, and/or 175 are correlated or
co-registered to angiographic image(s) and/or other two-dimensional
or three-dimensional depictions of a patient's vasculature obtained
by an external imaging system. In various embodiments, the
diagnostic information obtained by the external imaging system can
include externally-obtained angiographic images, x-ray images, CT
images, PET images, MM images, SPECT images, and/or other
two-dimensional or three-dimensional extraluminal depictions of a
patient's vasculature. Spatial co-registration can be completed
using techniques disclosed in U.S. Pat. No. 7,930,014, titled
"VASCULAR IMAGE CO-REGISTRATION," which is hereby incorporated by
reference in its entirety, based on the known pullback
speed/distance, based on a known starting point, based on a known
ending point, and/or combinations thereof. For example, a
mechanical pullback device can be used to conduct the
pressure-sensing procedure. The mechanical pullback device can move
the pressure-sensing device through the vessel at a fixed, known
rate. The location of the pressure measurements and/or the pressure
ratio(s) can be determined based on the rate of the pullback and a
known location of the pressure-sensing device (e.g., a start
position, a mid-point position, an end position, available from
angiography data). In some embodiments, diagnostic information
and/or data is correlated to vessel images using techniques similar
to those described in U.S. Provisional Patent Application No.
61/747,480, titled "SPATIAL CORRELATION OF INTRAVASCULAR IMAGES AND
PHYSIOLOGICAL FEATURES" and filed Dec. 31, 2012, which is hereby
incorporated by reference in its entirety. In some embodiments,
co-registration and/or correlation can be completed as described in
U.S. Provisional Patent Application No. 61/856,509, titled
"DEVICES, SYSTEMS, AND METHODS FOR ASSESSMENT OF VESSELS" and filed
Jul. 19, 2013, which is hereby incorporated by reference in its
entirety.
[0049] In some embodiments, diagnostic information and/or data is
correlated to vessel images using techniques similar to those
described in U.S. patent application Ser. No. 14/144,280, titled
"DEVICES, SYSTEMS, AND METHODS FOR ASSESSMENT OF VESSELS" and filed
Dec. 31, 2012, which is hereby incorporated by reference in its
entirety. In some embodiments, co-registration and/or correlation
can be completed as described in U.S. Provisional Patent
Application No. 61/856,509, titled "DEVICES, SYSTEMS, AND METHODS
FOR ASSESSMENT OF VESSELS" and filed Jul. 19, 2013, which is hereby
incorporated by reference in its entirety. In other embodiments,
co-registration and/or correlation can be completed as described in
International Application No. PCT/IL2011/000612, titled "CO-USE OF
ENDOLUMINAL DATA AND EXTRALUMINAL IMAGING" and filed Jul. 28, 2011,
which is hereby incorporated by reference in its entirety. Further,
in some embodiments, co-registration and/or correlation can be
completed as described in International Application No.
PCT/IL2009/001089, titled "IMAGE PROCESSING AND TOOL ACTUATION FOR
MEDICAL PROCEDURES" and filed Nov. 18, 2009, which is hereby
incorporated by reference in its entirety. Additionally, in other
embodiments, co-registration and/or correlation can be completed as
described in U.S. patent application Ser. No. 12/075,244, titled
"IMAGING FOR USE WITH MOVING ORGANS" and filed Mar. 10, 2008, which
is hereby incorporated by reference in its entirety.
[0050] Referring now to FIG. 5, shown therein is an exemplary
depiction of angiogram data as may be provided to the clinician in
a user interface 500, such as may be provided by the computing
device 172 of FIG. 4. The user interface 500 includes a window 502
that may be presented in the display 182 as seen in FIG. 4. The
window displays angiogram data that includes cardiac tissue 506 and
vasculature 508 obtained using a contrast agent. In some
embodiments, the angiogram 504 may be a three-dimensional angiogram
that may be manipulated by the clinician to provide different
views, including different perspective views and/or cross-sectional
views, of the patient's vasculature. During subsequent procedures,
the clinician may navigate the instruments 130 and/or 132 through
the patient's vasculature, collecting physiology measurements
therein. The physiology measurements may be stored in a memory of
the computing device 172 and also displayed on the display 182. The
image-based physiology measurements may include a dominance
classification, a degree of occlusion of a lesion, which may be
expressed as a percent diameter stenosis, a classification of a
lesion, a degree of bending of a vessel of the vessel system, a
length of a lesion, and/or a degree of calcification of a lesion.
In particular, the status of the system in regards to vessel
mapping, lesion identification, and lesion classification may be
seen in the windows 510, 520, 530 of the user interface 500. These
windows may display the status of the various features with an
on/off indicator as shown in FIGS. 5-8. The user interface 500 also
allows for selection of a certain area of the image. In this case,
no specific area is selected.
[0051] After obtaining the angiogram data, the data may be parsed
by an image-processing component provided by the system 150 of FIG.
4 to segment the patient's vasculature and estimate certain
features thereof. The parsing of the data may be performed to
extract image-based physiology measurements which may be
automatically displayed without the continued interaction of a
clinician. For example, the image-based physiology measurements may
be extracted after an angiogram collection process is complete.
[0052] When processing the angiogram data, quantitative coronary
angiography (QCA) may be used to assess and identify blockages from
the image-based data. A QCA process may be initiated automatically
to identify any blockages. While the clinician may provide a
qualitative evaluation based on his or her own experience, the
information from the QCA process may be used in subsequent steps to
automatically generate an objective intervention recommendation. As
is discussed in further detail below, co-registration techniques
incorporated herein by reference and others that may be known to
those of skill in the art may be used to co-register physiology
measurements to specific positions in a model of the patient's
vasculature 508 generated from the angiogram 504 presented in the
window 502.
[0053] Now referring to FIG. 6, the user interface 500 displays
data from the various sources as collected and analyzed by the
system 150. In particular, the vessel of the patient is actively
mapped according to the co-registered data. The status of the
system is shown as "on" in the window 510 pertaining to vessel
mapping. The user interface 500 may display the mapped vessels as a
colored region. The user is able to look at specific regions of the
mapped area to observe associated pressure readings and lesion
identification and classification. Further, as a result of the
vessel mapping the system may label the vessels accordingly. For
example, in the illustrated embodiment, the right coronary artery
is labeled "RCA," the left main artery is labeled "Left Main," the
left circumflex artery is labeled "LCX," the marginal branches are
labeled "M1" and "M2," the left anterior descending artery is
labeled "LAD," and the diagonal branch is labeled "D1." It is
understood that any vessels, including arteries and veins, may be
labeled in a similar manner. Further, a user may select the vessels
of interest such that only those vessels are labeled by the
system.
[0054] Automatic mapping of the vessel system by the system 150 may
be accomplished upon performing an image-recognition process on the
angiogram information such as that depicted in the user interface
500 of FIG. 5. The angiogram information may include information
characterizing or describing features of the vessel system such as
the contours, location, branches, and other features of the vessels
to automatically identify individual vessels within the patient's
vasculature. In this way, a model of the patient's vasculature may
be generated and parsed to identify specific sections which a user
may observe. Particular vessels which may be identified and mapped
by the system 150 include, but are not limited to, right coronary
artery (RCA), left main coronary artery (LCA), circumflex coronary
artery, left anterior descending (LAD), RCA proximal, RCA mid, RCA
distal, LAD proximal, LAD mid, LAD apical, first diagonal,
additional first diagonal, second diagonal, additional second
diagonal, proximal circumflex, intermediate/anterolateral, obtuse
marginal, distal circumflex, left posterolateral, posterior
descending, among others.
[0055] Markers 540 may be used in conjunction with the mapping of
the vessel system. As seen in FIG. 6, an FFR reading is shown at
the selected area of the LCA with marker 540. Other physiological
readings or anatomical labels may be displayed by markers 540.
Markers 540 can also be positioned automatically based on the
physiology measurements. The system can be configured to select
locations within the vessel that are clinically significant based
on the diagnostic information (e.g., locations where the physiology
measurements change significantly, such as points at which pressure
changes). Similarly, the markers 540 may be provided for various
predefined segments of the patient's vasculature. Markers 540 may
also be automatically generated based on the angiogram data using
image-recognition and modeling techniques. In some embodiments,
markers 540 are included automatically by the system 150 upon
performing an image-recognition process on the angiogram
information. The angiogram information may include, information
characterizing or describing features of the vessel system such as
the contours, location, branches, and other features of the
vessel(s) to automatically identify individual vessels within the
patient's vasculature. In this way, a model of the patient's
vasculature may be generated and parsed to identify specific
sections warranting the appropriate label.
[0056] It is understood that numerous other visualization
techniques may be utilized to convey the information of FIG. 6 in
the context of an angiographic image or other image of the vessel
(including both intravascular and extravascular imaging techniques,
such as IVUS, OCT, ICE, CTA, etc.) to help the user evaluate the
vessel. In that regard, while the examples of the present
disclosure are provided with respect to angiographic images, it is
understood that the concepts are equally applicable to other types
of vessel imaging techniques, including intravascular and
extravascular imaging. In some instances, a user is able to select
what information should be included or excluded from the displayed
image. In that regard, it should be noted that these visualization
techniques related to conveying the pressure measurement data in
the context of an angiographic or other image of the vessel can be
utilized individually and in any combinations. For example, in some
implementations a user is able to select what visualization mode(s)
and/or portions thereof will be utilized and the system outputs the
display accordingly. Further, in some implementations the user is
able to manually annotate the displayed image to include notes
and/or input one or more of the measured parameters.
[0057] The images of vessels in FIG. 6 can include
three-dimensional, two-dimensional, angiographic, a computed
tomography angiographic (CTA), and/or other suitable forms of
images. In some embodiments, a three-dimensional image may be
rotated about a vertical axis. In some embodiments, a
two-dimensional image may include multiple views about a vertical
axis such that different two-dimensional views are shown when the
image is rotated. In some implementations, the three dimensional
model is displayed adjacent to a corresponding two dimensional
depiction of the vessel. In that regard, the user may select both
the type of depiction(s) (two dimensional (including imaging
modality type) and/or three dimensional) along with what
visualization mode(s) and/or portions thereof will be utilized. The
system will output a corresponding display based on the user's
preferences/selections and/or system defaults.
[0058] FIG. 7 shows an exemplary user interface 500 with the vessel
mapping and lesion identification features activated. As in FIG. 6,
the windows 510, 520 corresponding to the features are labeled as
"on." In the embodiment shown, the lesion identification feature
displays regions of interest 522, 524 where lesions are likely to
be located. The identification of these area may be based on
physiology measurements. The system 150 can be configured to select
locations within the vessel that are clinically significant based
on the diagnostic information (e.g., locations where the physiology
measurements change significantly, such as points at which pressure
changes). Similarly, the one or more regions of interest may be
based on anatomical data the signals heightened risk of lesions,
such as the narrowing of a vessel. As seen in FIG. 7, regions of
interest 522, 524 can be identified without classifying the lesions
that are likely to exist at the defined areas. In this case, window
530 remains blank.
[0059] Referring now to FIG. 8, shown therein is a depiction of a
user interface 600 with activated features of vessel mapping,
lesion identification, and lesion classification. In this example,
the system 150 has identified two regions of interest 522, 524 and
has further classified the potential lesions on window 530 and in
on the user interface 500 with prompts 580, 590. The classification
of the diffuse lesions is based on the steady pressure drop over a
long portion of the vessel, while the classification of the focal
lesion is based on a sharp pressure drop at certain location on the
vessel. Markers 540, 560 may be used in lesion classification.
Additionally, markers 540, 560 may be used to further study the
identified lesions. For example, maker 560 shows a low pressure
reading at the center of the region of interest 524 which may
further define the classification as a severe focal lesion.
Classifications of lesions will be further discussed in relation to
FIG. 9.
[0060] Referring now to FIG. 9, shown therein is a depiction of a
user interface 600 for evaluating a vessel based on obtained
physiology measurements (as depicted, pressure measurements, but
may also include flow volume, flow velocity, and/or other
intravascular physiology measurements or calculations based
thereon) according to embodiments of the present disclosure. The
user interface may be displayed on a touch-sensitive display. A
clinician can view, analyze, and interact with the pressure data
and/or visual representations of the pressure data.
[0061] Referring more specifically to FIG. 9, shown therein is a
screen display 200 according to an embodiment of the present
disclosure. The screen display 200 includes multiple tabs,
including an iFR tab 202, an FFR tab 204, a patient tab 206, and a
settings tab 208. In FIG. 9, the iFR tab 202 has been selected and
displayed to a user. As shown, the iFR tab 202 includes a graph 210
and a corresponding pressure waveform plot 212. The screen display
200 also includes a window 214 that shows a calculated pressure
ratio (e.g., FFR, iFR, or otherwise). The screen display 200 also
includes a window 216 showing the runs or pullbacks available for
display to the user. In the illustrated embodiment, two different
runs are available and identified by a corresponding time stamp. In
that regard, a user can select the desired run from the window 216
and the data shown in the graph 210 and pressure waveform plot 212
will update accordingly.
[0062] The screen display 200 also includes zoom buttons 218, 220
that allow a user to zoom out or in, respectively, on the graph 210
and the pressure waveform plot 212. To this end, the screen display
200 includes a ruler 222 showing the relative scale of the graph
210 and the pressure waveform plot 212. In some instances, the
ruler 222 provides a dimensional scale of the graphical display of
the graph 210 and/or the pressure waveform plot 212 relative to the
vessel length and/or the pullback length. The scale of the ruler
222 automatically updates in response to selective actuation of the
zoom buttons 218, 220 in some implementations.
[0063] The screen display 200 also includes a slider 224. The
slider 224 allows the user to move along the length of the vessel
and/or the corresponding pullback data. For example, in some
instances the left end of the slider 224 corresponds to the
beginning of the pullback and the right end of the slider
corresponds to the end of the pullback. By moving the slider 224
between the first and second ends, a user can see corresponding
portions of the pressure data in the graph 210 and the pressure
waveform plot 212. Accordingly, a user can focus on certain
portions of the vessel and pullback data using the zoom buttons
218, 220 in combination with the slider 224. In some instances, the
numerical value of the pressure ratio displayed in window 214 is
updated based on the position of the slider and/or. In that regard,
in some instances the numerical value of the pressure ratio
displayed in window 214 is based solely on the pressure data being
displayed in the graph 210 and the pressure waveform plot 212.
However, in other instances the numerical value of the pressure
ratio displayed in window 214 is based one of or a combination of
the pressure data being displayed in the graph 210 and the pressure
waveform plot 212 and pressure data not displayed in the graph 210
and the pressure waveform plot 212.
[0064] In that regard, the graph 210 and pressure waveform plot 212
of screen display 200 illustrate aspects of pressure measurements
obtained as one instrument is moved through the vessel and another
instrument is maintained at a fixed location. In that regard, in
some instances the pressure measurements are representative of a
pressure ratio between a fixed location within the vessel and the
moving position of the instrument as the instrument is moved
through the vessel. For example, in some instances a proximal
pressure measurement is obtained at a fixed location within the
vessel while the instrument is pulled back through the vessel from
a first position distal of the position where the proximal pressure
measurement is obtained to a second position more proximal than the
first position (i.e., closer to the fixed position of the proximal
pressure measurement). For clarity in understanding the concepts of
the present disclosure, this arrangement will be utilized to
describe many of the embodiments of the present disclosure.
However, it is understood that the concepts are equally applicable
to other arrangements. For example, in some instances, the
instrument is pushed through the vessel from a first position
distal of the proximal pressure measurement location to a second
position further distal (i.e., further away from the fixed position
of the proximal pressure measurement). In other instances, a distal
pressure measurement is obtained at a fixed location within the
vessel and the instrument is pulled back through the vessel from a
first position proximal of the fixed location of the distal
pressure measurement to a second position more proximal than the
first position (i.e., further away from the fixed position of the
distal pressure measurement). In still other instances, a distal
pressure measurement is obtained at a fixed location within the
vessel and the instrument is pushed through the vessel from a first
position proximal of the fixed location of the distal pressure
measurement to a second position less proximal than the first
position (i.e., closer the fixed position of the distal pressure
measurement).
[0065] The pressure differential between the two pressure
measurements within the vessel (e.g., a fixed location pressure
measurement and a moving pressure measurement) is calculated as a
ratio of the two pressure measurements (e.g., the moving pressure
measurement divided by the fixed location pressure measurement), in
some instances. In some instances, the pressure differential is
calculated for each heartbeat cycle of the patient. In that regard,
the calculated pressure differential is the average pressure
differential across a heartbeat cycle in some embodiments. For
example, in some instances where a hyperemic agent is applied to
the patient, the average pressure differential across the heartbeat
cycle is utilized to calculate the pressure differential. In other
embodiments, only a portion of the heartbeat cycle is utilized to
calculate the pressure differential. The pressure differential is
an average over the portion or diagnostic window of the heartbeat
cycle, in some instances.
[0066] In some embodiments a diagnostic window is selected using
one or more of the techniques described in U.S. patent application
Ser. No. 13/460,296, filed Apr. 30, 2012 and titled "DEVICES,
SYSTEMS, AND METHODS FOR ASSESSING A VESSEL," which is hereby
incorporated by reference in its entirety. As discussed therein,
the diagnostic windows and associated techniques are particularly
suitable for use without application of a hyperemic agent to the
patient. In general, the diagnostic window for evaluating
differential pressure across a stenosis without the use of a
hyperemic agent is identified based on characteristics and/or
components of one or more of proximal pressure measurements, distal
pressure measurements, proximal velocity measurements, distal
velocity measurements, ECG waveforms, and/or other identifiable
and/or measurable aspects of vessel performance. In that regard,
various signal processing and/or computational techniques can be
applied to the characteristics and/or components of one or more of
proximal pressure measurements, distal pressure measurements,
proximal velocity measurements, distal velocity measurements, ECG
waveforms, and/or other identifiable and/or measurable aspects of
vessel performance to identify a suitable diagnostic window.
[0067] In the illustrated embodiment of FIG. 9, the graph 210 shows
the pressure ratio over time. In particular, the graph 210 shows
the pressure ratio calculated over the time of a pullback. More
specifically, the graph 210 shows an iFR pressure ratio value
during a pullback. In that regard, the iFR pressure ratio may be
calculated as described in one or more of PCT Patent Application
Publication No. WO 2012/093260, filed Jan. 6, 2012 and titled
"APPARATUS AND METHOD OF CHARACTERISING A NARROWING IN A FLUID
FILLED TUBE," PCT Patent Application Publication No. WO
2012/093266, filed Jan. 6, 2012 and titled "APPARATUS AND METHOD OF
ASSESSING A NARROWING IN A FLUID FILLED TUBE," U.S. patent
application Ser. No. 13/460,296, filed Apr. 30, 2012 and titled
"DEVICES, SYSTEMS, AND METHODS FOR ASSESSING A VESSEL," PCT Patent
Application Publication No. WO 2013/028612, filed Aug. 20, 2012 and
titled "DEVICES, SYSTEMS, AND METHODS FOR VISUALLY DEPICTING A
VESSEL AND EVALUATING TREATMENT OPTIONS," U.S. Provisional Patent
Application No. 61/856,509, filed Jul. 19, 2013 and titled
"DEVICES, SYSTEMS, AND METHODS FOR ASSESSMENT OF VESSELS," and U.S.
Provisional Patent Application No. 61/856,518, filed Jul. 19, 2013
and titled "DEVICES, SYSTEMS, AND METHODS FOR ASSESSING A VESSEL
WITH AUTOMATED DRIFT CORRECTION," each of which is hereby
incorporated by reference in its entirety.
[0068] The graph 210 can illustrate the pressure ratio and/or the
underlying pressure measurements in any suitable way. Generally
speaking, the representation of the data in graph 210 can be
utilized to identify gradients/changes in the pressure ratio and/or
the underlying pressure measurements that can be indicative of a
significant lesion in the vessel. In that regard, the visual
representation of the data can include the pressure measurement(s);
a ratio of the pressure measurements; a difference in the pressure
measurements; a gradient of the pressure measurement(s), the ratio
of the pressure measurements, and/or the difference in the pressure
measurements; first or second derivatives of the pressure
measurement(s), the ratio of the pressure measurements, and/or the
difference in the pressure measurements; and/or combinations
thereof.
[0069] Likewise, the pressure waveform plot 212 shows the
corresponding pressure data. In that regard, the pressure waveform
plot 212 can include the pressure waveform for the pressure sensing
device moved through the vessel during the pullback, the pressure
waveform for the stationary pressure sensing device, or both. In
the illustrated embodiment, the pressure waveform plot 212 includes
the pressure waveforms for both. In some instances the pressure
waveform plot 212 is augmented to highlight or otherwise accentuate
the pressure data corresponding to the diagnostic window utilized
for the pressure ratio calculations.
[0070] As shown in FIG. 9, the screen display 200 includes a button
226 indicating that the data is being displayed in a "Live" mode,
which indicates that the screen display 200, including graph 210,
pressure waveform plot 212, and/or the window 214, is being updated
in real time as a procedure is being performed. In other instances,
the button 226 of the screen display 200 will indicated that it is
in "Playback" or "Review" mode, which indicates that the screen
display 200 is showing data obtained previously. With respect to
the "Live" mode, it should be noted that the determination of the
diagnostic window and/or the calculation of the pressure
differential are performed in approximately real time or live to
identify the diagnostic window of the heartbeat cycle and calculate
the pressure differential. In that regard, calculating the pressure
differential in "real time" or "live" within the context of the
present disclosure is understood to encompass calculations that
occur within 10 seconds of data acquisition. It is recognized,
however, that often "real time" or "live" calculations are
performed within 1 second of data acquisition. In some instances,
the "real time" or "live" calculations are performed concurrent
with data acquisition. In some instances the calculations are
performed by a processor in the delays between data acquisitions.
For example, if data is acquired from the pressure sensing devices
for 1 ms every 5 ms, then in the 4 ms between data acquisitions the
processor can perform the calculations. It is understood that these
timings are for example only and that data acquisition rates,
processing times, and/or other parameters surrounding the
calculations will vary. In other embodiments, the pressure
differential calculation is performed 10 or more seconds after data
acquisition. For example, in some embodiments, the data utilized to
identify the diagnostic window and/or calculate the pressure
differential are stored for later analysis.
[0071] By comparing the calculated pressure differential to a
threshold or predetermined value, a physician or other treating
medical personnel can determine what, if any, treatment should be
administered. In that regard, in some instances, a calculated
pressure differential above a threshold value (e.g., 0.80 on a
scale of 0.00 to 1.00) is indicative of a first treatment mode
(e.g., no treatment, drug therapy, etc.), while a calculated
pressure differential below the threshold value is indicative of a
second, more invasive treatment mode (e.g., angioplasty, stent,
etc.). In some instances, the threshold value is a fixed, preset
value. In other instances, the threshold value is selected for a
particular patient and/or a particular stenosis of a patient. In
that regard, the threshold value for a particular patient may be
based on one or more of empirical data, patient characteristics,
patient history, physician preference, available treatment options,
and/or other parameters.
[0072] Also shown on FIG. 9 is region of interest 630. The region
of interest 630 may be assigned by the system 150 based on
anomalous readings from the instruments such as drastic pressure
changes in the vessel. In this embodiment, the region of interest
630 is centered around a sharp pressure change in the vessel. When
such an region of interest 630 is identified by the system 150, the
screen display 200 may show one or more options for taking further
diagnostic measurements of the region of interest 630. Therefore,
the screen display 200 as shown in FIG. 9 prompts a medical
professional to perform an IVUS measurement on the identified
section of the vessel which may be further confirmed by a
three-dimensional angiogram.
[0073] The coloring and/or other visually distinguishing aspect of
the pressure differential measurements depicted in graph 210 and/or
window 214 of the screen display 200 of FIG. 9 are configured based
on the threshold value in some instances. For example, a first
color (e.g., green, white, or otherwise) can be utilized to
represent values well above the threshold value (e.g., where the
threshold value is 0.80 on a scale of 0.00 to 1.00, values above
0.90), a second color (e.g., yellow, gray, or otherwise) can be
utilized to represent values near but above the threshold value
(e.g., where the threshold value is 0.80 on a scale of 0.00 to
1.00, values between 0.81 and 0.90), and a third color (e.g., red,
black, or otherwise) can be utilized to represent values equal to
or below the threshold value (e.g., where the threshold value is
0.80 on a scale of 0.00 to 1.00, values of 0.80 and below).
Further, in some instances the graph 210 includes one or more
horizontal lines or other depictions representing the threshold
value(s). It is appreciated that any number of color combinations,
scalings, categories, and/or other characteristics can be utilized
to visually represent the relative value of the pressure
differential to the threshold value. However, for the sake of
brevity Applicants will not explicitly describe the numerous
variations herein.
[0074] FIG. 10 shows diagrams of several classifications of lesions
that may be identified by the system 150, including "focal,"
"moderate," "severe," "diffuse," "long," "short," "multiple," and
"multi." Lesion 810 is made up of plaque buildup on both an upper
portion 116 and lower portion 118 of a vessel 100. A decrease in
the distance 802 between the upper and lower portions 116, 118 of
the plaque buildup leads to a decrease in pressure because the
plaque buildup decreases the available space for fluid to flow
through the vessel 100. This pressure drop may also be referred to
a as the functional intensity of the lesion. The classification of
the lesion can be derived from the functional intensity and the
length of the pressure drop across the vessel 100. In particular,
the functional intensity or slope of the pressure loss may be
mapped to a length of the vessel using techniques such as
co-registration of physiologic measurements such as FFR, iFR, CFR,
and angiography, and the results of the analysis may be compared to
a classification index containing the lesions classifications as
described below.
[0075] Lesion 810 causes a sharp pressure loss over a relatively
short length and is classified as "focal." Focal lesions may vary
greatly in severity, and may be further classified according to how
much they decrease the cross section if the vessel 100. This may be
measured by either a distance 802 or a percentage of the vessel
that is constricted. Because lesions may occur in vessels of many
different sizes, classification by a percentage may be favored. In
some cases, "moderate" focal lesions narrow the vessel 100 by
20-60%, whereas "severe" focal lesions narrow the vessel 100 by
60-100%.
[0076] In contrast to the focal lesion focal lesions, other lesions
cause a gradual pressure drop over a longer length of the vessel.
For example, lesion 820 is classified as "diffuse." As shown,
diffuse lesions often exhibit uneven plaque buildup along the
length of the vessel 100. Diffuse lesions may be further classified
based on their length 806 (i.e., the distance along the vessel 100
that the plaque extends on both sides of the vessel). In one
embodiment, lesions with a length of over 5 mm are classified as
"long," while lesions measuring 5 mm or less are classified as
"short." In some instances, multiple lesions exist within a vessel
100, such as those shown in example 830. Where the lesions are
close together, example 830 may be considered as a "multiple"
lesion classification. The distance 808 between lesions may
determine if they are separate focal lesions or a combined multiple
lesion. In one embodiment, where the lesions are less than 10 mm
apart, they may be considered as a multiple lesion. Lesion 840
shows complex plaque buildup forms on both sides of the vessel 100.
In this case, two lesions overlap within the vessel and the lesion
840 may be classified as "multi." This classification includes
multiple lesions located close together so that there is no
distance 808 between their areas of plaque buildup, while narrowed
sections occur at two or more points along the vessel 100. The
classification process of the present disclosure may involve
examining the vessel anatomy at the point of the suspected lesion.
In particular, the presence of plaque around a vessel bifurcation
can lead to anomalous classifications because pressure reading may
vary widely as a result of the bifurcation.
[0077] FIG. 11 is a flow diagram of a method 1000 of evaluating a
vessel system of a patient to identify and classify a lesion in the
vessel of a patient according to an embodiment of the present
disclosure. Method 1000 can be implemented by a system described
herein, such as system 150 of FIG. 4. As illustrated in FIG. 11,
the method 1000 is illustrated as a plurality of enumerated steps
or operations. Embodiments of the method 1000 may include
additional steps or operations before, after, in between, or as
part of the enumerated steps. At step 1002, method 1000 can include
obtaining image data from an image of a vessel system. This may be
done by contacting networked storage such as an electronic health
record storage system to obtain image data, such as angiogram data.
The angiogram data may include a two dimensional angiographic
image, a three dimensional angiographic image, and/or a computed
tomography angiographic (CTA) image. An example of the angiogram
data may be seen in the user interface 500 of FIGS. 5-8, which
includes the angiogram 504.
[0078] At step 1004, the method 1000 can include obtaining
physiology measurements from a first instrument and a second
instrument positioned within the vessel of the patient while the
second instrument is moved longitudinally through the vessel from a
first position to a second position. One or more diagnostic
measurements (e.g., pressure-based including FFR and iFR,
flow-based including CFR, etc.) can be used to gather the
physiology measurements to characterize the existence and/or
severity of a lesion or lesions within the vasculature of a
patient. For example, when FFR is used, areas of a patient's
vasculature that have a relatively high FFR (e.g., greater than
0.80) are characterized as not having a lesion or stenosis, while
areas with a relatively low FFR (e.g., less than 0.80) are
characterized as having a lesion or stenosis. The physiology
measurements may be obtained in a manner that provides at least
some location information associated with the measurements.
[0079] At step 1006, the method 1000 can include co-registering the
physiology measurements with the image data to produce
co-registered physiology measurements. The co-registered physiology
measurements can be displayed in an overlaid fashion, such that the
physiology measurements may be visualized in association with the
angiogram image data. An example may be seen in the user interface
500 of FIGS. 5-8. By co-registering the physiology measurements
with the image data, the system 150 may provide additional
perspective to a clinician or clinicians. The imagery may indicate
the physical dimensions of the patient's vasculature, which may be
sufficient to identify one or more lesions therein, while the
physiology measurements indicate the impact or effect of lesions
with the vasculature. In some embodiments, co-registering the
physiology measurements with the image data may include
associating, in a data file, each physiology measurement with a
location within the vessel system, identifying a corresponding
location for each physiology measurement with the image data, and
associating in the co-registered physiology measurements data file,
each physiology measurement with its corresponding location within
the image of the vessel system. In some embodiments, co-registering
the physiology measurements may produce a new data file that
includes the co-registered physiology measurements.
[0080] Co-registration may also be accomplished by overlaying the
data from imaging systems (such as angiographic images, x-ray
images, CT images, PET images, MM images, SPECT images, and/or
other two-dimensional or three-dimensional extraluminal depictions
of a patient's vasculature) with data obtained by instruments 130,
132, 152, and/or 175 of the system 150 (as shown in FIG. 4). In
some cases, information characterizing or describing features of
the vessel system such as the contours, location, branches, and
other features of the vessels are used to automatically identify
individual vessels within the patient's vasculature and serve as a
baseline for compiling a complete vessel map for a patient.
[0081] At step 1008, the method 1000 can include analyzing the
co-registered physiological measurements to determine the
classification of a lesion within the vessel. Potential regions of
interest where a lesion may be located are identified by the system
150 based on co-registered pressure readings and anatomical context
of the readings. Potential lesion locations may also be based on
anatomical physiological data such as unexpected narrowing of a
vessel or the existence of a side branch near a stenosis. Further
physiology information that may be considered in the identification
includes dominance classification, a degree of occlusion of the
lesion area, a degree of bending of a vessel of the vessel system,
a degree of calcification of the lesion area, etc. The
identification may also be based on a comparison of current
physiological measurements with previously recorded physiological
measurements from a database. Other sources of information that
form part of the analysis and formulation of the recommendation
include patient history such as age, gender, or preexisting
conditions such as diabetes or hypertension. After identifying
potential lesions, the system 150 classifies the lesions based on
functional parameters. Generally, the classification relies on the
cardiovascular pressure intensity and lesion length measurements.
Classifications of lesions that may be identified by the system 150
include "focal," "moderate," "severe," "diffuse," "long," "short,"
"multiple," "multi," or other suitable classification. The criteria
for making each of these classifications is discussed in
conjunction with FIG. 10.
[0082] At step 1010, the method 1000 can include displaying the
identification and classification of the lesion to a user. In some
embodiments, this information is automatically displayed on a user
interface 500 such as that shown in FIGS. 5-8. The identification
and classification may be read by medical professionals during the
course of a procedure to help guide diagnoses. Additionally, the
identification and classification may be used as an educational
too. For instance, the identification of the lesion and factors
used by the system 150 in the analysis used to formulate the
identification may be presented to a patient, or the family members
or guardian of a patient to help explain the reasoning of the
medical professional or the likelihood of future procedures.
[0083] Persons skilled in the art will also recognize that the
apparatus, systems, and methods described above can be modified in
various ways. Accordingly, persons of ordinary skill in the art
will appreciate that the embodiments encompassed by the present
disclosure are not limited to the particular exemplary embodiments
described above. In that regard, although illustrative embodiments
have been shown and described, a wide range of modification,
change, and substitution is contemplated in the foregoing
disclosure. It is understood that such variations may be made to
the foregoing without departing from the scope of the present
disclosure. Accordingly, it is appropriate that the appended claims
be construed broadly and in a manner consistent with the present
disclosure.
* * * * *