U.S. patent application number 17/477385 was filed with the patent office on 2022-01-06 for enhanced large-diameter balloon catheter.
The applicant listed for this patent is Biosense Webster (Israel) Ltd.. Invention is credited to Christopher Thomas Beeckler, Assaf Govari, Kevin Justin Herrera, Joseph Thomas Keyes.
Application Number | 20220000551 17/477385 |
Document ID | / |
Family ID | 1000005843738 |
Filed Date | 2022-01-06 |
United States Patent
Application |
20220000551 |
Kind Code |
A1 |
Govari; Assaf ; et
al. |
January 6, 2022 |
Enhanced Large-Diameter Balloon Catheter
Abstract
A balloon catheter includes a shaft, a balloon made of an
expandable membrane, a flexible substrate, one or more electrodes,
and one or more radiopaque flags. The shaft is configured for
insertion into a heart of a patient. The balloon is fitted at a
distal end of the shaft. The flexible substrate is disposed on the
membrane. The one or more electrodes are disposed over the flexible
substrate and have a fishbone configuration. The one or more
radiopaque flags are coupled to the expandable membrane, wherein
the one or more radiopaque flags include a serpentine pattern so
that the radiopaque flags fold in conformance with flexible
substrate as the balloon is collapsed into a compressed or folded
configuration.
Inventors: |
Govari; Assaf; (Haifa,
IL) ; Beeckler; Christopher Thomas; (Brea, CA)
; Keyes; Joseph Thomas; (Sierra Madre, CA) ;
Herrera; Kevin Justin; (West Covina, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Biosense Webster (Israel) Ltd. |
Yokneam |
|
IL |
|
|
Family ID: |
1000005843738 |
Appl. No.: |
17/477385 |
Filed: |
September 16, 2021 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
15993471 |
May 30, 2018 |
11123135 |
|
|
17477385 |
|
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61B 2218/002 20130101;
A61M 2025/1031 20130101; A61B 2018/0022 20130101; A61B 2018/00577
20130101; A61B 18/1492 20130101; A61B 5/062 20130101; A61B
2090/3966 20160201; A61B 2018/00357 20130101; A61B 2018/0016
20130101; A61M 2025/1079 20130101; A61M 2025/105 20130101; A61M
25/1034 20130101 |
International
Class: |
A61B 18/14 20060101
A61B018/14; A61B 5/06 20060101 A61B005/06; A61M 25/10 20060101
A61M025/10 |
Claims
1. A balloon catheter, comprising: a shaft configured for insertion
into a heart of a patient; an inflatable balloon coupled to a
distal end of the shaft, the balloon extending from a proximal
balloon portion to a distal balloon portion to define an equator of
the balloon about an axis extending from the proximal balloon
portion to the distal balloon portion; ten flexible substrates,
which are disposed on the balloon radially about a center of the
balloon, the flexible substrates extending from the distal balloon
portion of the balloon towards the proximal balloon portion, each
of the flexible substrates having its maximum width disposed
proximate the equator of the balloon; and first, second, third,
fourth, fifth, sixth, seventh, eighth, ninth and tenth radiopaque
flags disposed on respective ten flexible substrates, each of the
flags being disposed adjacent to the equator of the balloon.
2. The balloon catheter according to claim 1, and further
comprising: ten electrodes, which are disposed over each of the
respective ten flexible substrates; and irrigation pores disposed
over the balloon and some of the irrigation pores are distributed
over areas covered with the electrodes, and others of the
irrigation pores are distributed between the areas covered with the
electrodes.
3. The balloon catheter according to claim 1, and further
comprising a magnetic position sensor disposed on the shaft
proximally to the balloon.
4. The balloon catheter according to claim 1, wherein each of the
electrodes has its largest width proximate the equator of the
balloon and its smallest width proximate the distal balloon
portion.
5. The balloon catheter according to claim 1, and further
comprising a yarn disposed between the balloon and the flexible
substrate.
6. The balloon catheter according to claim 5, wherein the yarn is
selected from one of an ultra-high molecular weight fiber or a
liquid crystal polymer fiber.
7. The balloon catheter according to claim 1, wherein the flexible
substrate comprises a patterned topography that is configured to
increase adhesion of the flexible substrate to the balloon.
8. The balloon catheter according to claim 1, wherein each flexible
substrate extends from the distal balloon portion to the proximal
balloon portion and a width of the substrate, as measured parallel
to the equator of the balloon, increases gradually from the distal
balloon portion to its greatest width near the equator and
decreases gradually near the proximal portion of the balloon.
9. The balloon catheter according to claim 8, wherein each
electrode extends from a location near the distal balloon portion
towards the equator, the electrode having its greatest width near
the equator.
Description
PRIORITY
[0001] This patent application claims the benefit of priority under
35 USC .sctn. 120 to prior filed U.S. patent application Ser. No.
15/993,471 filed May 30, 2018 (Attorney Docket No. BIO5905USNP),
now allowed, which prior application is hereby incorporated by
reference as if fully set forth herein this application.
FIELD OF THE INVENTION
[0002] The present invention relates generally to medical probes,
and particularly to balloon catheters.
BACKGROUND OF THE INVENTION
[0003] Various known catheter designs have an inflatable ablation
balloon fitted at their distal end. For example, U.S. Patent
Application Publication 2011/0118632 describes a cardiac ablation
device that treats atrial fibrillation by directing and focusing
ultrasonic waves into a ring-like ablation region. The ablation
device can be steered and positioned without reference to
engagement between the device and the pulmonary vein or ostium. In
an embodiment, the device is located inside a structural balloon of
about 32 mm maximum diameter in the inflated condition.
[0004] As another example, U.S. Patent Application Publication
2010/0114269 describes a medical device that may include a catheter
body having proximal and distal portions, a fluid injection lumen
disposed within elongate body, and a guidewire lumen disposed
within the elongate body. A tip portion defining a cavity in fluid
communication with the fluid injection lumen may be coupled to the
distal end of the guidewire lumen, and an expandable element may be
coupled to the distal portion of the catheter body and to the tip
portion, such that the expandable element is in fluid communication
with the fluid injection lumen. A shaping element may at least
partially surround the expandable element, where the shaping
element is configurable in a first geometric configuration and a
second geometric configuration. The first geometric configuration
can include a diameter of approximately 23 mm and the second
geometric configuration can include a diameter of approximately 32
mm.
[0005] U.S. Patent Application Publication 2017/0312022 describes
an irrigated balloon catheter for use in an ostium of a pulmonary
vein, which includes a flexible circuit electrode assembly adapted
for circumferential contact with the ostium when the balloon is
inflated. Adapted for both diagnostic and therapeutic applications
and procedures, the balloon catheter may be used with a lasso
catheter or focal catheter. The flexible circuit electrode assembly
includes a substrate, a contact electrode on an outer surface of
the substrate, the contact electrode having a "fishbone"
configuration with a longitudinally elongated portion and a
plurality of transversal fingers, and a wiring electrode on an
inner surface of the substrate, and conductive vias extending
through the substrate electrically coupling the contact electrode
and the writing electrodes. Microelectrodes with exclusion zones
are strategically positioned relative to the electrodes. The
electrodes may also be split into electrode portions.
[0006] U.S. Patent Application Publication 2002/0160134 describes a
balloon catheter having a main-balloon, and a pilot-balloon system
that visually indicate the state of the inflation of the
main-balloon placed in a human body. The small pilot-balloon is
conveniently manufactured by blow molding utilizing substantially
the same material and has substantially the same structure as the
main balloon. The pilot-balloon is useful for a catheter with
balloon or a tube with cuff where the balloon or the cuff is made
of a very resilient material. The diameters of the main-balloon and
the pilot-balloon at three different inflation pressures were 31 mm
and 16 mm at 25 cm H2O, 32 mm and 17 mm at 34 cm H2O, and 34 mm and
18 mm, at 56 cm H2O, respectively.
SUMMARY OF THE INVENTION
[0007] We have encountered certain problems designing large
diameter balloon catheter with diameters greater than 28 mm. Some
of the problems were encountered in compressing such larger size
balloon (i.e., "crimped balloon") into a configuration small enough
so that the crimped balloon can be transported through the narrow
vein (via a catheter of approximately 5 French to approximately 15
French diameters) to the heart during a procedure. We were able to
devise various solutions to these problems, which solutions are set
forth and illustrated herein this application.
[0008] In one approach, we have devised a balloon catheter,
including a shaft, a balloon made of an expandable membrane, a
flexible substrate, one or more electrodes, and one or more
radiopaque flags. The shaft is configured for insertion into a
heart of a patient. The balloon is fitted at a distal end of the
shaft. The flexible substrate is disposed on the membrane. The one
or more electrodes are disposed over the flexible substrate and
have a fishbone configuration. The one or more radiopaque flags are
coupled to the expandable membrane, wherein the one or more
radiopaque flags include a serpentine pattern so that the
radiopaque flags fold in conformance with flexible substrate as the
expandable membrane is collapsed into a compressed or folded
configuration.
[0009] In some embodiments, the balloon catheter further includes
irrigation pores disposed over the membrane, some of the irrigation
pores are distributed over areas covered with the electrodes, and
others of the irrigation pores are distributed between the areas
covered with the electrodes.
[0010] In some embodiments, the radiopaque flags include at least
first and second flags that are patterned with different shapes to
indicate, when X-ray imaged, an orientation of the balloon
catheter.
[0011] In an embodiment, the balloon catheter further includes a
magnetic position sensor that is disposed proximally to the
balloon.
[0012] In another embodiment, the balloon catheter further includes
a yarn disposed between the membrane and the flexible
substrate.
[0013] In some embodiments, the yarn is selected from one of an
ultra-high molecular weight fiber or a liquid crystal polymer
fiber.
[0014] In an embodiment, the flexible substrate includes a
patterned topography that is configured to increase adhesion of the
flexible substrate to the membrane.
[0015] There is additionally provided, in accordance with an
embodiment of the present invention a method for manufacturing a
balloon catheter, the method including providing a shaft that is
configured for insertion into a heart of a patient. A distal end of
the shaft is fitted with a balloon made of an expandable membrane.
A flexible substrate is disposed on the membrane. One or more
electrodes having a fishbone configuration are disposed over the
flexible substrate. One or more radiopaque flags having a
serpentine pattern are disposed over the flexible substrate. The
electrodes and the serpentine radiopaque flags are conformed with
the membrane in a compressed configuration.
[0016] The present invention will be more fully understood from the
following detailed description of the embodiments thereof, taken
together with the drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a schematic, pictorial illustration of a
catheter-based position-tracking and ablation system comprising a
Radiofrequency (RF) ablation balloon, in accordance with an
embodiment of the present invention;
[0018] FIG. 2 is a schematic pictorial illustration of the balloon
catheter from FIG. 1, in accordance with an embodiment of the
present invention;
[0019] FIG. 3 is a detailed schematic pictorial top view of a
flexible circuit electrode assembly, in accordance with an
embodiment of the present invention;
[0020] FIG. 4 is a pictorial top view of the flexible circuit
electrode assembly, in accordance with another embodiment of the
present invention;
[0021] FIG. 5 is a schematic pictorial top view of a spatial
arrangement of radiopaque flags, in accordance with an embodiment
of the present invention; and
[0022] FIG. 6 is a pictorial volume rendering of radiopaque flags
on a balloon, as would be seen with X-ray imaging, in accordance
with an embodiment of the present invention.
DETAILED DESCRIPTION OF EMBODIMENTS
Overview
[0023] An expandable ablation balloon may be fitted at a distal end
of a catheter that is navigated through the cardiovascular system
and inserted into a heart, e.g., for ablating an ostium of a
pulmonary vein. The balloon should be large enough so as not to
inadvertently enter the vein, but also must be packed in a
sufficiently compact form that will allow advancing the balloon
through narrow blood vessels. An additional challenge is to ensure
safe collapse and retraction of such a balloon back into the
catheter sheath in order to remove the balloon from the body after
treatment. As used herein, the terms "about" or "approximately" for
any numerical values or ranges indicate a suitable dimensional
tolerance that allows the part or collection of components to
function for its intended purpose as described herein. More
specifically, "about" or "approximately" may refer to the range of
values.+-.10% of the recited value, e.g. "about 90%" may refer to
the range of values from 81% to 99%. In addition, as used herein,
the terms "patient," "host," "user," and "subject" refer to any
human or animal subject and are not intended to limit the systems
or methods to human use, although use of the subject invention in a
human patient represents a preferred embodiment.
[0024] Embodiments of the present invention that are described
hereinafter enable reliable collapse, and retraction into the
sheath, of an ablation balloon with a diameter sufficiently large
not to enter a pulmonary vein. In some embodiments, the required
balloon diameter, when inflated, is set to approximately 32
millimeters. Elements disposed on the balloon membrane (i.e.,
wall), such as electrodes and radiopaque flags, are configured to
withstand delaminating forces as the balloon collapses, during
which the larger membrane stretches and/or develops folds.
[0025] In particular, the elements are designed to stretch and/or
fold in a conformal manner so as to accommodate stresses that might
otherwise cause delamination of the elements from the membrane
and/or otherwise prevent sufficient collapsing of the balloon.
Additionally or alternatively, at least some of the elements are
designed to limit stresses, such as might occur due to
overstretching.
[0026] One of the elements is a radiopaque flag, which is disposed
on a flexible substrate, which itself is attached to the balloon
membrane (e.g., glued on an outer surface of the balloon wall). The
radiopaque flag, the flexible substrate, and the membrane, are all
designed, and are attached to each other, so as to stretch and/or
fold together in a manner that allows collapsing the balloon, and
safely withdrawing the balloon, into the sheath of the
catheter.
[0027] In some embodiments, the radiopaque flag is designed with a
serpentine pattern to enable the radiopaque flag to stretch and/or
fold in a conformal manner (i.e., to fold in conformance with
flexible substrate as the expandable membrane is collapsed into a
compressed or folded configuration). For the same reason, the
flexible substrate comprises a patterned topography, such as a
crisscross pattern topography or a matrix or other pattern of blind
holes/shapes, which is configured to increase adhesion of the
flexible substrate to the balloon membrane, and which, after being
glued to the membrane, increases grip area. In this way, the
flexible substrate and the membrane stretch and/or fold in a manner
conformal with each other, remaining intact when the balloon is
collapsed.
[0028] In an embodiment of the present invention, one or more
radiopaque flags are patterned with shapes to indicate the
orientation of the balloon catheter, providing directional and
orientation guidance to the operator, as further elaborated below.
In some embodiments, a magnetic position sensor is disposed within
the catheter shaft, just proximal to the balloon, so that a
magnetic position tracking system can assist navigation of the
balloon.
[0029] In an embodiment, an ablation-electrode, disposed over the
flexible substrate, has a fishbone configuration with a
longitudinally (i.e., parallel to the distal end of the shaft)
elongated portion and a plurality of transversal fingers. This
configuration facilitates the stretching and/or folding of the
electrode so it will not delaminate during the collapse of the
balloon and its retraction back into the sheath.
[0030] In some embodiments, irrigation pores are distributed over
the membrane. Some of the irrigation pores are distributed over
areas covered with the electrodes, while other irrigation pores are
distributed between the areas covered with the electrodes. The
homogenous distribution of the irrigation pores over the surface of
the balloon may ensure more reliable and uniform cooling of tissue
and blood during ablation.
[0031] The disclosed solutions allow the collapsing of a large
balloon into a sufficiently compact form to safely retract the
balloon into a catheter sheath, which otherwise may be very hard to
achieve, and be potentially unsafe to attempt performing, during a
clinical procedure. The disclosed enhanced balloon diameter is
large enough to safely ablate an ostium of a pulmonary vein, and
afterwards to be safely retracted out of the heart of a
patient.
System Description
[0032] FIG. 1 is a schematic, pictorial illustration of a
catheter-based position-tracking and ablation system 20 comprising
an RF ablation balloon 40, in accordance with an embodiment of the
present invention. System 20 comprises a catheter 21, wherein, as
seen in inset 25, a distal end 22a of shaft 22 of catheter 21 is
inserted through a sheath 23 into a heart 26 of a patient 28 lying
on a table 29. As further shown in inset 25, distal end 22a
comprises a magnetic sensor 39, contained within distal end 22a
just proximally to balloon 40.
[0033] The proximal end of catheter 21 is connected to a control
console 24. In the embodiment described herein, catheter 21 may be
used for any suitable therapeutic and/or diagnostic purpose, such
as electrical sensing and/or ablation of tissue in heart 26.
[0034] During navigation of distal end 22a in heart 26, console 24
receives signals from magnetic sensor 39 in response to magnetic
fields from external field generators 36, for example, for the
purpose of measuring the position of ablation balloon 40 in the
heart and, optionally, presenting the tracked position on a display
27. Magnetic field generators 36 are placed at known positions
external to patient 28, e.g., below patient table 29. Console 24
also comprises a driver circuit 34, configured to drive magnetic
field generators 36.
[0035] In an embodiment, position signals received from position
sensor 39 are indicative of the position of ablation balloon 40 in
the coordinate system of position tracking and ablation system 20.
The method of position sensing using external magnetic fields is
implemented in various medical applications, for example, in the
CARTO.TM. system, produced by Biosense-Webster Inc. (Irvine,
Calif.), and is described in detail in U.S. Pat. Nos. 5,391,199,
6,690,963, 6,484,118, 6,239,724, 6,618,612 and 6,332,089, in PCT
Patent Publication WO 96/05768, and in U.S. Patent Application
Publications 2002/0065455 A1, 2003/0120150 A1 and 2004/0068178 A1,
whose disclosures are all incorporated herein by reference.
[0036] Physician 30 navigates the distal end of shaft 22 to a
target location in heart 26 by manipulating shaft 22 using a
manipulator 32 near the proximal end of the catheter and/or
deflection from the sheath 23. During the insertion of shaft 22,
balloon 40 is maintained in a collapsed configuration by sheath 23.
By containing balloon 40 in a collapsed configuration, sheath 23
also serves to minimize vascular trauma along the way to target
location.
[0037] Control console 24 comprises a processor 41, typically a
general-purpose computer, with suitable front end and interface
circuits 38 for receiving signals from catheter 21, as well as for
applying treatment via catheter 21 in heart 26 and for controlling
the other components of system 20. Processor 41 typically comprises
a general-purpose computer with software programmed to carry out
the functions described herein. The software may be downloaded to
the computer in electronic form, over a network, for example, or it
may, alternatively or additionally, be provided and/or stored on
non-transitory tangible media, such as magnetic, optical, or
electronic memory.
[0038] The example configuration shown in FIG. 1 is chosen purely
for the sake of conceptual clarity. The disclosed techniques may
similarly be applied using other system components and settings.
For example, system 20 may comprise other components and perform
non-cardiac ablative treatments.
Enhanced Large Diameter Balloon Catheter
[0039] FIG. 2 is a schematic pictorial illustration of balloon
catheter 40 from FIG. 1, in accordance with an embodiment of the
present invention. As seen, balloon 40 is fitted at distal end 22a
(of shaft 22) that protrudes from sheath 23. Magnetic position
sensor 39 is contained within distal end 22a just proximally to
balloon 40. Expandable balloon 40 has an exterior wall or membrane
43 of a bio-compatible material, for example, formed from a plastic
such as polyethylene terephthalate (PET), polyurethane or
PEBAX.RTM.. Ablation-electrodes 46 are disposed in circumference
over balloon 40, on flexible substrates 44.
[0040] Balloon 40 has a distal end and a proximal end defining a
longitudinal axis. In some embodiments, balloon 40 is expanded and
contracted (i.e., collapsed) using a "balloon advancer" rod (not
shown). The rod may be extended outwardly from shaft 22 to
longitudinally elongate balloon 40 into an oblong shape. It may be
withdrawn to provide the balloon with a spherical shape. The
balloon advancer rod is the primary mechanism for changing the
shape of balloon 40 between spherical and oblong configurations,
while filling the balloon with saline further tightens the skin of
the balloon to the spherical shape.
[0041] In some embodiments balloon 40 comprises irrigation pores
47a and 47b, through which saline solution is irrigated for cooling
tissue and blood during ablation. Pores 47a are located in areas
covered by electrodes 46, whereas pores 47b are located over
membrane 43 between areas covered by electrodes 46.
[0042] In some embodiments, radiopaque flags 52 are patterned in
different serpentine shapes. In an embodiment of the present
invention, the differently shaped radiopaque flags 52 provide
orientation and directional guidance, as further elaborated below.
An electrophysiology catheter disposed with two or more radiopaque
markers having distinct forms of each other is described in U.S.
patent application Ser. No. 15/939,154, filed Mar. 28, 2018,
entitled "Irrigated Electrophysiology Catheter with Distinguishable
Electrodes for Multi-Electrode Identification and Orientation Under
2-D Visualization," which is assigned to the assignee of the
present patent application and whose disclosure is incorporated
herein by reference.
[0043] The diameter of balloon 40, when inflated, is defined by an
equator 45 over the exterior of membrane 43, wherein the equator
lies in a plane perpendicular to the axis of distal end 22a. In
some embodiments, when inflated, the balloon equatorial diameter
(i.e., the diameter of equator 45) measures approximately
thirty-two millimeters.
[0044] An inset 42 of FIG. 2 shows a cross sectional view of
balloon 40 in a collapsed state (e.g., ready to be retracted into
sheath 23). As seen in inset 42, when the balloon is collapsed,
membrane 43 and flexible substrate 44, while mainly stretched as
elongated by the extender rod, may still develop folds. Such folds
put stress on flexible substrate 44, or on elements disposed over
flexible substrate 44, which might result in delamination. As
balloon diameter increases, more pronounced folding may occur as
the balloon is forcibly collapsed, thus increasing the delaminating
forces. Moreover, if some disposed elements are too rigid, either
axially or transversely, they may hinder collapsing the balloon
sufficiently to retract it safely into sheath 23. In some
embodiments of the present invention, elements disposed on the
membrane are designed so they, and the membrane, will axially
stretch and/or transversely fold in a mutually conformal manner, as
explained in the detailed description of FIG. 3, so as to avoid the
problems described above.
[0045] An irrigated balloon ablation catheter is described in U.S.
Publication No. 2017/0312022, titled "Irrigated balloon catheter
with flexible circuit electrode assembly," the entire content of
which is incorporated herein by reference.
[0046] The example illustration shown in FIG. 2 is chosen purely
for the sake of conceptual clarity. Other sizes of balloon 40 and
various configurations of its components, such as of
ablation-electrodes 46, are possible. When inflated, the equatorial
diameter of balloon 40 can be larger or smaller than thirty-two
millimeters.
[0047] FIG. 3 is a detailed schematic pictorial top view of a
flexible circuit electrode assembly, in accordance with an
embodiment of the present invention. In an embodiment, an ablation
electrode 46 has a form of a "fishbone," advantageously increasing
the circumferential or equatorial contact surface of electrode 46
with tissue. At the same time, a fishbone form more easily
stretches and/or folds in a conformal manner so as to allow the
collapse of balloon 40 into a sufficiently tight form about distal
end 22a.
[0048] As seen in FIG. 3, radiopaque flags or markers 52 are
patterned in serpentine shapes, in order to allow radiopaque flags
52 to fold in a manner conformal with flexible substrate 44 as
balloon 40 is collapsed. Also seen are irrigation pores 47a, which
are located in areas not covered by electrodes 46.
[0049] In an embodiment, a yarn or fiber 60 made of Liquid Crystal
Polymer (LCP) such as, for example, Vectran.RTM. or Ultra High
Molecular Weight Polyethylene (UHMWPE) such as, for example,
Dyneema.RTM., runs between membrane 43 and flexible substrate 44
from one end of flexible substrate 44 to the other. Due to the high
elastic modulus of yarn 60, the yarn or fiber limits any axial
stretch, while balloon 40 collapses, that might otherwise cause
delamination. The yarn also prevents tearing of the flexible
substrate 44 at its narrow distal tail, which does not have any
metal to limit the elongation. The yarn allows the application of
significant distal force with a balloon advancer rod on the lumen
(by surrounding membrane 43), so as to evacuate the internal saline
solution without risk of damaging any electrical circuits attached
to flexible substrate 44.
[0050] A zoom-in on an edge area 44a of flexible substrate 44 shows
a crisscross pattern 50 topography (i.e., "waffle" pattern) put
into edge area 44a to increase adhesion of flexible substrate 44 to
membrane 43, after flexible substrate 44 is glued to membrane 43.
The waffle pattern provides the necessary adhesion by increasing
grip area for the adhesive, which both strengthens the bond and
withstands delaminating forces acting on substrate 44 that occur as
balloon 40 is collapsed for retraction into sheath 23. As is
further seen in FIG. 3, in a zoom-in on flexible substrate 44, a
plurality of perforations 50 is patterned, wherein perforations 50
are configured to receive an adhesive for affixing the substrate 44
to the membrane 43.
[0051] The example top view shown in FIG. 3 is chosen purely for
the sake of conceptual clarity. Other materials may be used, for
example, yarn 60 may be made of a para-aramid. In an alternative
embodiment for radiopaque flags 52, seen in FIG. 4, a different
solution to withstanding delamination is exemplified, as explained
below.
[0052] FIG. 4 is a pictorial top view of the flexible circuit
electrode assembly, in accordance with another embodiment of the
present invention. As seen, a radiopaque flag 53 is split into
radiopaque flags 53a and 53b, in order to allow the radiopaque
flags to stretch more easily in the longitudinal direction.
Additionally, radiopaque flag 53a has a form of a voided triangle,
to indicate an orientation when imaged by X-ray.
[0053] FIG. 5 is a schematic pictorial top view of the spatial
arrangement of radiopaque flags 52, in accordance with an
embodiment of the present invention. Light gray outlines of
flexible substrates 44 can also be seen. To indicate an
orientation, some of the ten shown radiopaque flags 52 are
patterned with unique features. As shown in FIG. 5, radiopaque
flags 52 (seen numbered 1 to 10) can be divided into a first type
and a second type of flags. Flags of a first type, such as flag
52a, have a distinct feature. Flags of a second type are identical
one with the other, e.g., all comprising a plain line. Flags 52 are
designed this way to indicate to physician 30 an orientation of
electrodes 46, and, in that way, of balloon 40 as a whole, inside a
chamber of heart 26. For example, radiopaque flag 52a includes the
pattern of a hollow arrow, while radiopaque flag 52b includes a
pattern of full arrow.
[0054] The example shown in FIG. 5 is chosen purely for the sake of
conceptual clarity. Other patterns may be designed and used. The
number and the arrangement of uniquely patterned radiopaque flags
in FIG. 5 is brought by way of example, and may generally vary.
[0055] FIG. 6 is a pictorial volume rendering of radiopaque flags
52 on a balloon, as would be seen with X-ray imaging, in accordance
with an embodiment of the present invention. As FIG. 6 shows, an
X-ray image of balloon 40 may resolve radiopaque flags 52a and 52b
to indicate to physician 30 a sense of spatial orientation of
balloon 40.
[0056] Although the embodiments described herein mainly address
cardiac balloon catheters, the methods and systems described herein
can also be used in other applications, such as in otolaryngology
or neurology procedures.
[0057] It will thus be appreciated that the embodiments described
above are cited by way of example, and that the present invention
is not limited to what has been particularly shown and described
hereinabove. Rather, the scope of the present invention includes
both combinations and sub-combinations of the various features
described hereinabove, as well as variations and modifications
thereof which would occur to persons skilled in the art upon
reading the foregoing description and which are not disclosed in
the prior art. Documents incorporated by reference in the present
patent application are to be considered an integral part of the
application except that to the extent any terms are defined in
these incorporated documents in a manner that conflicts with the
definitions made explicitly or implicitly in the present
specification, only the definitions in the present specification
should be considered.
* * * * *