U.S. patent application number 16/335394 was filed with the patent office on 2019-09-12 for intracardiac echocardiography (ice) catheter tip assembly.
The applicant listed for this patent is KONINKLIJKE PHILIPS N.V.. Invention is credited to Maritess Minas, Princeton Saroha, Jeremy Stigall, Nathan Andrew Williams.
Application Number | 20190274658 16/335394 |
Document ID | / |
Family ID | 60083260 |
Filed Date | 2019-09-12 |
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United States Patent
Application |
20190274658 |
Kind Code |
A1 |
Stigall; Jeremy ; et
al. |
September 12, 2019 |
INTRACARDIAC ECHOCARDIOGRAPHY (ICE) CATHETER TIP ASSEMBLY
Abstract
An imaging catheter assembly is provided. In one embodiment, the
imaging catheter assembly includes a flexible elongate member
comprising a distal portion and a proximal portion; a tip member
coupled to a distal end of the distal portion of the flexible
elongate member, wherein the tip member includes a tubular body
comprising a closed distal end, an opened proximal end, and a
proximal curved top outer wall extending from the proximal opened
end and tapering into a distal flat top outer wall towards the
closed distal end; and an imaging component mounted within the tip
member. In one embodiment, the imaging catheter assembly includes a
flexible elongate member; a tip member coupled to a distal end of
the flexible elongate member, wherein the tip member includes a
cylindrical body and a uniform outer diameter; and an imaging
component mounted within the tip member.
Inventors: |
Stigall; Jeremy; (Carlsbad,
CA) ; Saroha; Princeton; (Ladera Ranch, CA) ;
Minas; Maritess; (San Diego, CA) ; Williams; Nathan
Andrew; (San Diego, MA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KONINKLIJKE PHILIPS N.V. |
EINDHOVEN |
|
NL |
|
|
Family ID: |
60083260 |
Appl. No.: |
16/335394 |
Filed: |
September 25, 2017 |
PCT Filed: |
September 25, 2017 |
PCT NO: |
PCT/EP2017/074157 |
371 Date: |
March 21, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62401525 |
Sep 29, 2016 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61B 8/12 20130101; A61B
8/445 20130101; A61B 8/4461 20130101; A61B 8/4483 20130101; A61B
8/0883 20130101 |
International
Class: |
A61B 8/12 20060101
A61B008/12; A61B 8/00 20060101 A61B008/00 |
Claims
1. An imaging catheter assembly, comprising: a tip member
comprising a tubular body that includes a closed distal end, an
opened proximal end, and a proximal curved top outer wall extending
from the proximal opened end and tapering into a distal flat top
outer wall towards the closed distal end; a flexible elongate
member comprising a distal portion coupled to the open proximal end
of the tip member; and an imaging component mounted within the tip
member.
2. The imaging catheter assembly of claim 1, wherein the closed
distal end comprises a rounded profile.
3. The imaging catheter assembly of claim 1, wherein the tip member
is constructed from a material including a polyether block
amide.
4. The imaging catheter assembly of claim 1, wherein the tubular
body includes an inner cavity extending from the proximal opened
end towards the distal closed end, and wherein the inner cavity
includes a proximal curved top inner wall opposite the proximal
curved top outer wall and a distal flat top inner wall opposite the
distal flat top outer wall.
5. The imaging catheter assembly of claim 4, wherein the imaging
component comprises a planar element that includes an ultrasound
transducer array.
6. The imaging catheter assembly of claim 5, wherein the distal
flat top outer wall at least partially forms an imaging window for
the ultrasound transducer array.
7. The imaging catheter assembly of claim 5, wherein the imaging
component is positioned within the inner cavity such that the
ultrasound transducer array emits ultrasound beams towards and
through the distal flat top inner wall and the distal flat top
outer wall.
8. The imaging catheter assembly of claim 5, wherein the imaging
component is positioned about parallel to the distal flat top inner
wall, and wherein a wall thickness between the distal flat top
inner wall and the distal flat top outer wall is less than 200
microns.
9. The imaging catheter assembly of claim 5, wherein the imaging
component is enclosed within the inner cavity by a material
including at least one of a polydimethylsiloxane (PDMS),
polyurethane, or ultraviolet (UV) adhesive.
10. The imaging catheter assembly of claim 5, wherein the inner
cavity further includes: a first guiding member extending along a
first inner sidewall of the inner cavity; and a second guiding
member extending along a second inner sidewall of the inner cavity,
wherein the first inner sidewall is radially opposite the second
inner sidewall, and wherein the imaging component is positioned
within the tip member guided by the first guide member and the
second guide member.
11. The imaging catheter assembly of claim 5, wherein the inner
cavity includes a first keyed inner wall surface, wherein the
distal portion of the flexible elongate member further comprises a
connecting member, and wherein the connecting member includes a
second keyed surface inter-engaging with the first keyed inner wall
surface.
12. The imaging catheter assembly of claim 11, further comprising a
plurality of steering lines coupled to the connecting member and
extending along the flexible elongate member, wherein the plurality
of steering lines are oriented relative to the second keyed surface
such that translation of each of the plurality of steering lines
deflects the tip member in an associated pre-defined direction
relative to a longitudinal axis of the flexible elongate
member.
13-22. (canceled)
23. The imaging catheter assembly of claim 1, wherein the tubular
body comprises a substantially uniform diameter between the closed
distal end and the open proximal end, wherein the inner cavity
includes a distal section comprising a first cross-section
configured to receive the imaging component, and a proximal section
comprising a second cross-section configured to receive the distal
portion of the flexible elongate member.
24. The imaging catheter assembly of claim 1, wherein the first
guiding member comprises a first step ledge, and the second guiding
member comprises a second step ledge.
25. The imaging catheter assembly of claim 1, wherein the first
guiding member comprises a first pair of rails, and the second
guiding member comprises a second pair of rails.
Description
TECHNICAL FIELD
[0001] The present disclosure relates generally to ultrasound
catheters, in particular, to steerable ultrasound intracardiac
echocardiography (ICE) catheters having tip members shaped and
sized to optimize ultrasonic imaging performance and to facilitate
alignment during manufacturing.
BACKGROUND
[0002] Diagnostic and therapeutic ultrasound catheters have been
designed for use inside many areas of the human body. In the
cardiovascular system, two common diagnostic ultrasound methods are
intravascular ultrasound (IVUS) and intra-cardiac echocardiography
(ICE). Typically a single rotating transducer or an array of
transducer elements is used to transmit ultrasound at the tips of
the catheters. The same transducers (or separate transducers) are
used to receive echoes from the tissue. A signal generated from the
echoes is transferred to a console which allows for the processing,
storing, display, or manipulation of the ultrasound-related
data.
[0003] IVUS catheters are typically used in the large and small
blood vessels (arteries or veins) of the body, and are almost
always delivered over a guidewire having a flexible tip. ICE
catheters are usually used to image chambers of the heart and
surrounding structures, for example, to guide and facilitate
medical procedures, such as transseptal lumen punctures, left
atrial appendage closures, atrial fibrillation ablation, and valve
repairs. Commercially-available ICE catheters are not designed to
be delivered over a guidewire, but instead have distal ends which
can be articulated by a steering mechanism located in a handle at
the proximal end of the catheter. For example, an ICE catheter may
be inserted through the femoral or jugular artery when accessing
the anatomy, and steered in the heart to acquire images necessary
to the safety of the medical procedures.
[0004] One type of ICE catheter (EP Medsystems ViewFlex.TM.
Intracardiac Ultrasound Deflectable catheter) has a distal
articulation in a single plane (both directions), operated by a
single wheel that rotates about the lengthwise axis of the handle.
The wheel is turned to a specific position for the desired catheter
shape, staying in place due to the inherent friction on the wheel
mechanism. The catheter is torquable, and can be rotated with the
handle to facilitate steering in a second plane. The motions
required to simultaneously torque and rotate the catheter often
require two-handed operation.
[0005] Another type of ICE catheter (Siemens/ACUSON AcuNav.TM.
Ultrasound Catheter) has an additional steering plane, and each
steering plane is utilized by turning one of two corresponding
wheels on the handle. These wheels rotate about the lengthwise axis
of the handle. A third wheel, which also rotates about the
lengthwise axis of the handle, is a locking mechanism for freezing
each of the two steering wheels in its respective orientation. The
entire catheter need not be torqued. The two steering planes allow
a large combination of possible catheter configurations.
[0006] ICE catheters commonly provide steering through pullwires
secured to the distal portions of the catheters near the tip
assemblies. The pullwires are also referred to as steering lines.
The pullwires extend through the bodies of the catheters and are
coupled to control wheels at handles of the catheters located at
the proximal end of catheters. For example, a pair of pullwires may
provide steering in a left-right plane and another pair of
pullwires may provide steering in an anterior-posterior plane.
Thus, the maneuvering or turning of a control wheel in turn
actuates a corresponding pullwire to deflect the distal portion of
a catheter in a corresponding direction.
[0007] An ICE catheter typically includes an ultrasound imaging
core that generates and receives acoustic energy. The imaging core
may include a linear array of transducer elements or transducer
elements arranged in any suitable configuration. The imaging core
is encased in a tip member located at a furthest distal tip of the
catheter. The tip member is covered with acoustic adhesive
materials. An electrical cable is soldered to the imaging core and
extends through the core of the body of the catheter. The
electrical cable may carry control signals and echo signals to
facilitate imaging of the heart anatomy.
[0008] The tip member acts as a barrier between the imaging core
and the body of a patient. The shape, geometry, and material type
of the tip member may have an impact on the ultrasonic imaging
performance. For example, the tip member may attenuate, distort,
and/or reflect acoustic energy emitted by the transducer elements
and echoes from reflections of the acoustic energy by the body.
SUMMARY
[0009] The invention provides devices, systems, and related methods
that overcome the limitations associated with existing designs and
provide improved ultrasound imaging performance.
[0010] Embodiments of the present disclosure provide a catheter
with a tip member configured to improve ultrasonic imaging
performance and to facilitate alignment during manufacturing. The
outer geometry, the internal cavity, and the wall thickness of the
tip member are shaped to minimize attenuations, distortions, and/or
reflections of acoustic energy along acoustic pathway of an imaging
core encased within the tip member. For example, the tip member is
configured to have a circular shaft and a flat window at the distal
portion at which the imaging core resides such that the thickness
of the wall in the direction of the acoustic waves is minimal The
material of the tip member is selected to further minimize the
attenuations, distortions, and/or reflections. In addition, the tip
member is configured to have a smooth transition from the flat
window to the circular shaft to eliminate any ledges or
perpendicular surfaces on the outer wall. Further, the internal
cavity is configured to function as an alignment agent for aligning
the imaging core to pullwires of the catheter body such that
actuations of the pullwires can orient the image core to provide a
consistent angular view during imaging.
[0011] In one embodiment, an imaging catheter assembly is provided.
The imaging catheter assembly includes a tip member comprising a
tubular body that includes a closed distal end, an opened proximal
end, and a proximal curved top outer wall extending from the
proximal opened end and tapering into a distal flat top outer wall
towards the closed distal end; a flexible elongate member
comprising a distal portion coupled to the open proximal end of the
tip member; and an imaging component mounted within the tip
member.
[0012] In some embodiments, the closed distal end comprises a
rounded profile. In some embodiments, the tip member is constructed
from a material including a polyether block amide. In some
embodiments, the tubular body includes an inner cavity extending
from the proximal opened end towards the distal closed end, and the
inner cavity includes a proximal curved top inner wall opposite the
proximal curved top outer wall and a distal flat top inner wall
opposite the distal flat top outer wall. In some embodiments, the
imaging component comprises a planar element that includes an
ultrasound transducer array. In some embodiments, the distal flat
outer wall at least partially forms an imaging window for the
ultrasound transducer array. In some embodiments, the imaging
component is positioned within the inner cavity such that the
ultrasound transducer array emits ultrasound beams towards and
through the distal flat top inner wall and the distal flat top
outer wall. In some embodiments, the imaging component is
positioned about parallel to the distal flat top inner wall, and a
wall thickness between the distal flat top inner wall and the
distal flat top outer wall is less than 200 microns. In some
embodiments, the imaging component is enclosed within the inner
cavity by a material including at least one of a
polydimethylsiloxane (PDMS), polyurethane, or ultraviolet (UV)
adhesive. In some embodiments, the inner cavity further includes: a
first guiding member extending along a first inner sidewall of the
inner cavity and a second guiding member extending along a second
inner sidewall of the inner cavity, where the first inner sidewall
is radially opposite the second inner sidewall and the imaging
component is positioned within the tip member guided by the first
guide member and the second guide member. In some embodiments, the
inner cavity includes a first keyed inner wall surface positioned
relative to a propagation direction of the ultrasound beams,
wherein the distal portion of the flexible elongate member further
comprises a connecting member, and wherein the connecting member
includes a second keyed surface inter-engaging with the first keyed
inner wall surface. In some embodiments, the imaging catheter
assembly further comprises a plurality of steering lines coupled to
the connecting member and extending along the flexible elongate
member, wherein the plurality of steering lines are oriented
relative to the second keyed surface such that translation of each
of the plurality of steering lines deflects the tip member in an
associated pre-defined direction relative to a longitudinal axis of
the flexible elongate member.
[0013] In one embodiment, an imaging catheter assembly is provided.
The imaging catheter assembly includes a tip member comprising a
cylindrical body that includes a closed distal end and an opened
proximal end, the cylindrical body having a substantially uniform
diameter between the closed distal end and open proximal end and
defining an inner lumen of variable cross-sections, the inner lumen
having a distal section with a first cross-section configured to
receive an imaging component and proximal section having a second
cross-section configured to receive a distal portion of a flexible
elongate member, the second cross-section being different than the
first cross-section; a flexible elongate member coupled to the open
proximal end of the tip member such that at least a distal portion
of the flexible elongate member is received within the proximal
section of the inner lumen of the tip member; and an imaging
component mounted within the distal section of the inner lumen of
the tip member.
[0014] In some embodiments, the tip member is constructed from a
material including a polyether block amide. In some embodiments,
the closed distal end includes a rounded profile. In some
embodiments, the proximal section of the inner lumen includes a
curved top inner wall and the distal section of the inner lumen
includes a flat top inner wall. In some embodiments, the imaging
component is a planar element including an ultrasound transducer
array, and wherein the imaging component is positioned within the
distal section of the inner lumen such that the ultrasound
transducer array emits ultrasound beams towards and through the
flat top inner wall. In some embodiments, the imaging component is
enclosed within the distal section of the inner lumen by a
material, the material including at least one of a
polydimethylsiloxane (PDMS), polyurethane, or ultraviolet (UV)
adhesive. In some embodiments, the distal section of the inner
lumen further includes a first guiding member extending along a
first inner sidewall and a second guiding member extending along a
second inner sidewall opposite the first inner sidewall, wherein
the imaging component is positioned between the first guide member
and the second guide member. In some embodiments, the distal
portion of the flexible elongate member includes a keyed structure
to mate with the proximal section of the inner lumen of the tip
member in a predefined orientation. In some embodiments, the distal
portion of the flexible elongate member includes a connecting
member and a plurality of steering lines coupled to the connecting
member, the plurality of steering lines extending along the
flexible elongate member to a proximal portion of the flexible
elongate member. In some embodiments, the plurality of steering
lines are oriented relative to the keyed structure such that
translation of each of the plurality of steering lines deflects the
tip member in an associated pre-defined direction relative to a
longitudinal axis of the flexible elongate member.
[0015] Additional aspects, features, and advantages of the present
disclosure will become apparent from the following detailed
description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Illustrative embodiments of the present disclosure will be
described with reference to the accompanying drawings, of
which:
[0017] FIG. 1 is a schematic diagram of an ICE imaging system
according to embodiments of the present disclosure.
[0018] FIG. 2 is a schematic diagram of a portion of an ICE device
according to embodiments of the present disclosure.
[0019] FIG. 3 is a schematic diagram of a portion of an ICE device
under deflection according to embodiments of the present
disclosure.
[0020] FIG. 4 is a schematic diagram illustrating deflections
planes of an ICE device according to embodiments of the present
disclosure.
[0021] FIG. 5 is a schematic diagram illustrating an
interconnection within an ICE device between a tip assembly and a
flexible elongate member according to embodiments of the present
disclosure.
[0022] FIG. 6A is a perspective view of a crown element according
to embodiments of the present disclosure.
[0023] FIG. 6B is a bottom view of a crown element according to
embodiments of the present disclosure.
[0024] FIG. 6C is a side view of a crown element according to
embodiments of the present disclosure.
[0025] FIG. 7 is a side view of a crown element with a pullwire in
position according to embodiments of the present disclosure.
[0026] FIG. 8A is a perspective view of a sleeve element according
to embodiments of the present disclosure.
[0027] FIG. 8B is a top view of a sleeve element according to
embodiments of the present disclosure.
[0028] FIG. 9 is a top view of a sleeve element according to
embodiments of the present disclosure.
[0029] FIG. 10 is a flow diagram of a method of assembling an ICE
device according to aspects of the disclosure.
[0030] FIG. 11 is a schematic diagram illustrating a crown element
fitted over an electrical cable, in a stage of assembly, according
to embodiments of the disclosure.
[0031] FIG. 12 is a schematic diagram illustrating a pair of
pullwires anchored to a crown element, in a stage of assembly,
according to embodiments of the disclosure.
[0032] FIG. 13 is a schematic diagram illustrating a pair of
pullwires anchored to a crown element and threaded through a
flexible elongate member, in a stage of assembly, according to
embodiments of the disclosure.
[0033] FIG. 14 is a schematic diagram illustrating a crown element
positioned for coupling, in a stage of assembly, according to
embodiments of the disclosure.
[0034] FIG. 15 is a schematic diagram illustrating a sleeve element
positioned for coupling, in a stage of assembly, according to
embodiments of the disclosure.
[0035] FIG. 16 is a schematic diagram illustrating a sleeve element
bonded to a tip assembly and a flexible elongate member, in a stage
of assembly, according to embodiments of the disclosure.
[0036] FIG. 17 is a side view of a tip member according to
embodiments of the present disclosure.
[0037] FIG. 18 is a side perspective view of a tip member according
to embodiments of the present disclosure.
[0038] FIG. 19 is a cross-sectional view of a tip member according
to embodiments of the present disclosure.
[0039] FIG. 20 is a cross-sectional view of a tip member according
to embodiments of the present disclosure.
[0040] FIG. 21 is a cross-sectional view of a tip member according
to embodiments of the present disclosure.
[0041] FIG. 22 is a cross-sectional view of a tip member according
to embodiments of the present disclosure.
[0042] FIG. 23 is a back perspective view of a tip member according
to embodiments of the present disclosure.
[0043] FIG. 24 is a back perspective view of a tip member with an
imaging core in position according to embodiments of the present
disclosure.
[0044] FIG. 25 is a cross-sectional side view of an imaging core
according to embodiments of the present disclosure.
[0045] FIG. 26 is a perspective view of a tip assembly and a sleeve
element positioned for coupling according to embodiments of the
present disclosure.
[0046] FIG. 27 is a side perspective view of a tip member according
to embodiments of the present disclosure.
[0047] FIG. 28 is a back perspective view of a tip member with an
imaging core in position according to embodiments of the present
disclosure.
[0048] FIG. 29 is a side perspective view of a tip member according
to embodiments of the present disclosure.
[0049] FIG. 30 is a back perspective view of a tip member with an
imaging core in position according to embodiments of the present
disclosure.
[0050] FIG. 31 is a cross-sectional view of a lined variable
braided differential durometer multi-lumen catheter shaft according
to embodiments of the present disclosure.
[0051] FIG. 32 is a cross-sectional longitudinal view of a lined
variable braided differential durometer multi-lumen catheter shaft
according to embodiments of the present disclosure.
[0052] FIG. 33 is a perspective view of a multi-lumen inner
extrusion in a stage of manufacturing according to embodiments of
the present disclosure.
[0053] FIG. 34 is a perspective view of a braid reinforced inner
extrusion in a stage of manufacturing according to embodiments of
the present disclosure.
[0054] FIG. 35 is a perspective view of a single-lumen outer
extrusion inserted over a braided inner extrusion in a stage of
manufacturing according to embodiments of the present
disclosure.
DETAILED DESCRIPTION
[0055] 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. For example,
while the ICE system is described in terms of cardiovascular
imaging, it is understood that it is not intended to be limited to
this application. The system is equally well suited to any
application requiring imaging within a confined cavity. 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.
[0056] FIG. 1 is a schematic diagram of an ICE imaging system 100
according to embodiments of the present disclosure. The system 100
may include an ICE device 110, a connector 124, a control and
processing system 130, such as a console and/or a computer, and a
monitor 132. The ICE device 110 includes a tip assembly 102, a
flexible elongate member 108, and a handle 120. The flexible
elongate member 108 includes a distal portion 104 and a proximal
portion 106. The distal end of the distal portion 104 is attached
to the tip assembly 102. The proximal end of the proximal portion
106 is attached to the handle 120 for example, by a resilient
strain reliever 112, for manipulation of the ICE device 110 and
manual control of the ICE device 110. The tip assembly 102 can
include an imaging core with ultrasound transducer elements and
associated circuitry. The handle 120 can include actuators 116, a
clutch 114, and other steering control components for steering the
ICE device 110, such as deflecting the tip assembly 102 and the
distal portion 104, as described in greater details herein.
[0057] The handle 120 is connected to the connector 124 via another
strain reliever 118 and an electrical cable 122. The connector 124
may be configured in any suitable configurations to interconnect
with the processing system 130 and the monitor 132 for processing,
storing, analyzing, manipulating, and displaying data obtained from
signals generated by the imaging core at the tip assembly 102. The
processing system 130 can include one or more processors, memory,
one or more input devices, such as keyboards and any suitable
command control interface device. The processing system 130 can be
operable to facilitate the features of the ICE imaging system 100
described herein. For example, the processor can execute computer
readable instructions stored on the non-transitory tangible
computer readable medium. The monitor 132 can be any suitable
display device, such as liquid-crystal display (LCD) panel or the
like.
[0058] In operation, a physician or a clinician advances the
flexible elongate member 108 into a vessel within a heart anatomy.
The physician or clinician can steer the flexible elongate member
108 to a position near the area of interest to be imaged by
controlling the actuators 116 and the clutch 114 on the handle 120.
For example, one actuator 116 may deflect the tip assembly 102 and
the distal portion 104 in a left-right plane and the other actuator
116 may deflect the tip assembly 102 and the distal portion 104 in
an anterior-posterior plane, as discussed in greater details
herein. The clutch 114 provides a locking mechanism to lock the
positions of the actuators 116 and in turn the deflection of the
flexible elongate member while imaging the area of interest.
[0059] The imaging process may include activating the ultrasound
transducer elements on the tip assembly 102 to produce ultrasonic
energy. A portion of the ultrasonic energy is reflected by the area
of interest and the surrounding anatomy, and the ultrasound echo
signals are received by the ultrasound transducer elements. The
connector 124 transfers the received echo signals to the processing
system 130 where the ultrasound image is reconstructed and
displayed on the monitor 132. In some embodiments, the processing
system 130 can control the activation of the ultrasound transducer
elements and the repletion of the echo signals. In some
embodiments, the processing system 130 and the monitor 132 may be
part of the same system.
[0060] The system 100 may be utilized in a variety of applications
such as transseptal lumen punctures, left atrial appendage
closures, atrial fibrillation ablation, and valve repairs and can
be used to image vessels and structures within a living body.
Although the system 100 is described in the context of ICE
catheterization procedures, the system 100 is suitable for use with
any catheterization procedure. In addition, the tip assembly 102
may include any suitable physiological sensor or component for
diagnostic, treatment, and/or therapy.
[0061] FIG. 2 is a schematic diagram of a portion of the ICE device
110 according to embodiments of the present disclosure. The tip
assembly 102 and the flexible elongate member 108 are shaped and
sized for insertion into vessels of a patient body. The flexible
elongate member 108 can be composed of any suitable material, such
as polyether block amides. The distal portion 104 and the proximal
portion 106 are tubular in shape and may include a primary lumen
and one or more pullwire lumens extending longitudinally along the
flexible elongate member 108. The primary lumen is sized and shaped
to accommodate an electrical cable interconnecting the tip assembly
102 and the connector 124 for transferring echo signals obtained
from the transducer elements. In some embodiments, the primary
lumen can be shaped and sized to accommodate other components for
diagnostic and/or therapy procedures. The pullwire lumens are sized
and shaped to accommodate pullwires, for example, extending from
the distal portion 104 to the handle 120. The pullwires may be
coupled to the actuators 116 and the clutch 114 such that the
flexible elongate member 108 and the tip assembly 102 are
deflectable based on actuations of the actuators 116 and the clutch
114. In an embodiment, the primary lumen is shaped to facilitate
alignment of the pullwire lumens. In addition, the tubular body of
the flexible elongate member 108 may include a lined variable
braided reinforcement layer configured to provide flexibility and
kink resistance. The arrangements and configurations of the
pullwires, the primary lumen, the pullwire lumens, the tip assembly
102, and the lined variable braided reinforcement layer are
described in greater details herein. Dimensions of the flexible
elongate member 108 can vary in different embodiments. In some
embodiments, the flexible elongate member 108 can be a catheter
having an outer diameter between about 8 and about 12 French (Fr)
and can have a total length 206 between about 80 centimeters (cm)
to about 120 cm, where the proximal portion 106 can have a length
204 between about 70 cm to about 118 cm and the distal portion 104
can have a length 202 between about 2 cm to about 10 cm.
[0062] FIG. 3 is a schematic diagram of a portion of the ICE device
110 under deflection according to embodiments of the present
disclosure. For example, the flexible elongate member 108 shown in
FIG. 2 is referred to as a neutral position. In FIG. 3, the tip
assembly 102 and the distal portion 104 of the flexible elongate
member 108 are deflected from the neutral position. In an
embodiment, the distal portion 104 may be deflected up to a bend
radius 305 of about 27 millimeters (mm) to about 28 mm.
[0063] FIG. 4 is a schematic diagram illustrating deflections
planes of the ICE device 110 according to embodiments of the
present disclosure. As shown, the tip assembly 102 and the distal
portion 104 can be deflected along a first plane as shown by the
solid arrows and a second plane as shown by the dotted arrows. In
FIG. 3, the first plane is represented by an x-y plane and the
second plane is represented by an x-z plane. For example, the x-y
plane may correspond to a left-right plane and the x-z plane may
correspond to an anterior-posterior plane for imaging the heart
anatomy.
[0064] FIG. 5 is a schematic diagram illustrating an
interconnection within the ICE device 110 between the tip assembly
102 and the flexible elongate member 108 according to embodiments
of the present disclosure. As shown, the interconnection between
the tip assembly 102 and the distal portion 104 of the flexible
elongate member 108 includes a crown element 520 and a sleeve
element 540. The crown element 520 is coupled to the distal end of
the distal portion 104. The sleeve element 540 is coupled to the
crown element 520 and the proximal end of the tip assembly 102. The
tip assembly 102 includes an imaging core 562 encased in a tip
member 560. For example, the imaging core 562 is a planar element.
The tip assembly 102 can include an alignment portion (not shown)
shaped to facilitate alignment during manufacturing, as described
in greater detail herein. The imaging core 562 is connected to an
electrical cable 566 via an electrical interconnection 564. The
electrical cable 566 extends longitudinally along the flexible
elongate member 108. The crown element 520 and the sleeve element
540 are fitted around the electrical cable 566.
[0065] A more detailed view of the crown element 520 is illustrated
in FIG. 6A and dimensions of the crown element 520 are illustrated
in FIGS. 6B and C. The crown element 520 functions as an anchor for
pullwires 507 such that the tip assembly 102 and the distal portion
104 may be deflectable upon actuations of the pullwires 507 in the
proximal direction as shown in FIGS. 3 and 4 and described in
greater detail herein. The anchoring of the pullwires 507 to the
crown element 520 is illustrated in FIG. 7. The sleeve element 540
functions as an alignment agent to align the crown element 520 and
the pullwires 507 such that the deflection may provide predictable
or predetermined articulation views as described in greater detail
herein. A more detailed view of the sleeve element 540 is
illustrated in FIG. 8A. The alignment between the sleeve element
540 and the tip assembly 102 is illustrated in FIG. 26.
[0066] In an embodiment, the flexible elongate member 108 may
include a lined variable braided enforcement layer to provide
flexibility and kink resistance as described in greater detail
herein. In such an embodiment, the interconnection further includes
a braid containment 502 positioned between an anchoring segment 503
and the distal end of the flexible elongate member 108. The braid
containment 502 may be composed of material such as polyethylene
terephthalate (PET) or any suitable material. The anchoring segment
503 can be composed of similar material as the flexible elongate
member 108. The braid containment 502 functions as a termination
for the braided reinforcement layer. The braid containment 502
encases the termination of the materials (e.g., stainless steel
wires) of the braided reinforcement layer to prevent exposure of
the materials outside of the ICE device 110. The structure of the
flexible elongate member 108 and the braided reinforcement layer
are described in greater detail herein. The anchoring segment 503
couples the braid containment 502 to the crown element 520 and the
sleeve element 540 to allow for thermal reflow when bonding the
components at the interconnection.
[0067] The interconnection may further include support members 508
and 509, which are thin sleeves, to provide protection over
connections of different components. The support members 508 and
509 may be composed of any suitable polymeric material. As shown,
the support member 508 is positioned over the connections among the
sleeve element 540, the tip assembly 102, the crown element 520,
and the anchoring segment 503. The support member 509 is positioned
over the connections among the braid containment 502, the anchoring
segment 503, and the distal portion 104 of the flexible elongate
member 108.
[0068] FIG. 6A is a perspective view of the crown element 520
according to embodiments of the present disclosure. FIG. 6B is a
bottom view of the crown element 520 according to embodiments of
the present disclosure. FIG. 6C is a side view of the crown element
520 taken along the line 601 of FIG. 6B according to embodiments of
the present disclosure. The crown element 520 includes an annular
ring 522 and support legs or posts 528 and 529. The crown element
520 is composed of a material dissimilar or incompatible with the
material of the flexible elongate member 108. For example, the
crown element 520 is composed of a thermoset material such as metal
or plastic polymer. The annular ring 522 includes a top surface 524
and a bottom surface 526. The posts 528 and 529 are positioned
about radially opposite of each other on the annular ring 522 and
extend about perpendicularly from the bottom surface 526. Each of
the posts 528 and 529 has a hole 530 positioned at an end of each
of the posts 528 and 529, respectively, away from the annular ring
522 and along a central axis of the posts 528 and 529,
respectively. A pair of pullwires such as the pullwires 507 can be
secured to the crown element 520, one at each of the posts 528 and
529. The edges of the annular ring 522 are curved or rounded, for
example, with small radii, to eliminate breakage of the pullwires
during multiple actuations.
[0069] Dimensions of the crown element 520 can vary in different
embodiments depending on the dimensions of the flexible elongate
member 108. In some embodiments, the annular ring 522 can have an
outer radius 611 between about 5 FR and about 11 FR and an inner
radius 612 between about 4 FR and about 10 FR. Each of the posts
528 and 529 can have a height 613 between about 1 mm and 3 mm and a
width 614 between about 0.25 mm and 1.5 mm. Each hole 530 can have
a radius 615 between about 0.05 mm and 0.7 mm. In some embodiments,
the outer radius 611 can be less than the outer diameter of the
flexible elongate member 108 while the inner radius 612 can be
greater than the radius of the primary lumen of the flexible
elongate member 108.
[0070] FIG. 7 is a side view of the crown element 520 taken along
the line 601 of FIG. 6B with a pullwire 700 similar to the
pullwires 507 in position according to embodiments of the present
disclosure. The pullwire 700 can be composed of metal, hard
plastic, or any suitable material. As shown, the pullwire 700 is
anchored to the crown element 520 by forming a knot 710 at the post
528 creating segments 721 and 722 separated by the post 528. The
post 528 provides connection security and stability when the
segments 721 and 722 are actuated. The separation of the segments
721 and 722 by the post 528 allows actuations of the segments 721
and 722 to be independent of each other, and thus provides
consistent bending of the ICE device 110 over multiple actuations
of the segments 721 and 722. For example, an actuation of the
segment 721 deflects the ICE device 110 in one direction and
actuation of the segment 722 deflects the ICE device 110 in another
direction. Another pullwire similar to the pullwires 700 and 507
can be anchored to the crown element 520 at the other post 529
using similar mechanisms to provide deflection of the ICE device
110 along a different plane. Thus, the crown element 520 enables
independent and consistent actuations of the pullwire segments. In
addition, the head 711 of the knot 710 is placed at the inner wall
of the crown element 520 to minimize the amount of dissimilar
material outside of the crown element 520 that can weaken the joint
between the crown element 520 and the sleeve element 540 after
bonding.
[0071] FIG. 8A is a perspective view of the sleeve element 540
according to embodiments of the present disclosure. FIG. 8B is a
top view of the sleeve element 540 according to embodiments of the
present disclosure. The sleeve element 540 has a tubular body and
includes flat outer surface portions 542 and 544 and curved outer
surface portions 546 and 548. The sleeve element 540 is composed of
a material compatible to the flexible elongate member 108 and the
tip assembly 102. For example, the sleeve element 540 can be
composed of a plastic polymer. The flat outer surface portions 542
and 544 have about the same surface area. The curved outer surface
portions 546 and 548 have about the same surface area. The flat
outer surface portion 542 is adjacent to the curved outer surface
portions 546 and 548. The flat outer surface portion 544 is
adjacent to the curved outer surface portions 546 and 548. The flat
outer surface portions 542 and 544 are about radially opposite of
each other. The sleeve element 540 further includes slots 551 and
552 extending longitudinally along the tubular body. The slot 551
is positioned proximal to the flat outer surface portion 542 and
curved outer surface portion 546. The slot 552 is positioned
proximal to the flat outer surface portion 544 and curved outer
surface portion 548.
[0072] During assembly or manufacturing, the posts 528 and 529 of
the crown element 520 are fitted into the slots 551 and 552,
respectively, and thermally bonded. After the bonding, the holes
530 are filled with the material of the sleeve element 540. Thus,
the holes 530 allow for a stronger bond and improve tensile
strength at the joint between the crown element 520 and the sleeve
element 540. Since the pullwires are anchored at the posts 528 and
529 and the posts 528 and 529 are fitted into the slots 551 and
552, respectively, the positioning of the slots 551 and 552
relative to the flat outer surface portions 542 and 544 can
facilitate alignment of the pullwires to the imaging core 562 such
that actuations of the pullwires can provide consistent
articulation views, as described in greater detail herein.
[0073] Dimensions of the sleeve element 540 can vary in different
embodiments depending on the dimensions of the flexible elongate
member 108. For example, the outer diameter 814 may be smaller than
the inner diameter of the proximal opening 568 of the tip member
560 such that the sleeve element 540 may be fitted into the
proximal opening 568 of the tip member 560. The widths 813 of the
slots 551 and 552 may be greater than the widths 614 of the posts
528 and 529 such that the posts 528 and 529 may be inserted into
the slots 551 and 552, respectively. For example, the material of
the sleeve element 540 may be pliable and may conform to the
inserted posts 528 and 529.
[0074] FIG. 9 is a top view of a sleeve element 900 according to
embodiments of the present disclosure. The sleeve element 900 can
be employed by the ICE device 110 in place of the sleeve element
540. The sleeve element 900 is similar to the sleeve element 540,
but has a curved outer surface 910 without any flat portion as in
the sleeve element 540. The sleeve element 900 can include slots
921 and 922 similar to the slots 551 and 552, which can be used for
fitting the posts 528 and 529, respectively, when bonded with the
crown element. The sleeve element 900 can be used when the tip
assembly 102 does not include an alignment portion for alignment.
In some embodiments, a sleeve element can be shaped to have an
outer surface portion different from remaining outer surface to
allow for alignment, where the outer surface portion can be in any
shape suitable for alignment.
[0075] A method 1000 of assembling the ICE device 110 is described
with reference made to FIGS. 10-16. FIG. 10 is a flow diagram of a
method 1000 of assembling the ICE device 110 according to aspects
of the disclosure. It is understood that additional steps can be
provided before, during, and after the steps of method 1000, and
some of the steps described can be replaced or eliminated for other
embodiments of the method. The steps of the method 1000 can be
carried out by a manufacturer of an ICE device. FIG. 11 is a
schematic diagram illustrating the crown element 520 fitted over
the electrical cable 566, in a stage of assembly, according to
embodiments of the disclosure. FIG. 12 is a schematic diagram
illustrating a pair of pullwires 700 and 740 anchored to the crown
element 520, in a stage of assembly, according to embodiments of
the disclosure. FIG. 13 is a schematic diagram illustrating the
pair of pullwires 700 and 740 anchored to the crown element 520 and
threaded through the flexible elongate member 108, in a stage of
assembly, according to embodiments of the disclosure. FIG. 14 is a
schematic diagram illustrating the crown element 520 positioned for
coupling, in a stage of assembly, according to embodiments of the
disclosure. FIG. 15 is a schematic diagram illustrating the sleeve
element 540 positioned for coupling, in a stage of assembly,
according to embodiments of the disclosure. FIG. 16 is a schematic
diagram illustrating the sleeve element 540 bonded to the tip
assembly 102 and the flexible elongate member 108, in a stage of
assembly, according to embodiments of the disclosure.
[0076] Referring to the step 1005 of the method 1000, in an
embodiment, the tip assembly 102 coupled to the electrical cable
566 is obtained. Referring to the step 1010 of the method 1000 and
FIG. 11, in an embodiment, the crown element 520 is positioned
around the electrical cable 566. FIG. 11 illustrates the electrical
cable 566 pre-loaded with the crown element 520. As shown, the
crown element 520 is positioned such that the posts 528 and 529
extend towards the tip assembly.
[0077] Referring to the step 1015 of the method 1000 and FIG. 12,
in an embodiment, the pullwire 700 is secured to the crown element
520 by looping the pullwire 700 around the annular ring 522 at the
post 528 to form the two segments 721 and 722. FIG. 12 illustrates
a pair of pullwires 700 and 740 anchored to the crown element 520.
The pullwire 700 is anchored to the annular ring 522 at the post
528 using similar knotting mechanisms shown in FIG. 7. Similarly,
the pullwire 740 is anchored to the annular ring 522 at the post
529 by forming a Larks knot 743, which creates segments 741 and
742. It should be noted that the heads of the knots 710 and 743 are
placed adjacent to the inner wall of the crown element 520. In an
embodiment, the segments 721 and 722 are for steering the distal
portion 104 and the tip assembly 102 in a left direction and an
anterior direction, respectively. The segments 741 and 742 are for
steering the distal portion 104 and the tip assembly 102 in a right
direction and a posterior direction, respectively.
[0078] Referring to the step 1020 of the method 1000 and FIG. 13,
in an embodiment, each segment 721 or 722 is positioned within one
of a plurality of pullwire lumens 582 of the flexible elongate
member 108. FIG. 13 illustrates the pair of pullwires 700 and 740
anchored to the crown element 520 and threaded through the flexible
elongate member 108. As shown, the segment 721 is threaded through
one of the pullwire lumens 582 of the flexible elongate member 108.
Although not shown, each of the segments 722, 741, and 742 can be
thread through one of the pullwire lumens 582.
[0079] Referring to the step 1025 of the method 1000 and FIGS. 14
and 15, in an embodiment, the sleeve element 540 is positioned
between the crown element 520 and the tip assembly 102. FIG. 14
illustrates the crown element 520 positioned for coupling. As
shown, the crown element 520 is positioned abutting the distal end
of the flexible elongate member 108. FIG. 15 illustrates the sleeve
element 540 positioned for coupling. As shown, the sleeve element
540 is positioned between the crown element 520 and the tip
assembly 102.
[0080] Referring to the step 1030 of the method 1000, in an
embodiment, the posts 528 and 529 are fitted into the slots 551 and
552, respectively, of the sleeve element 540.
[0081] Referring to the step 1035 of the method 1000, in an
embodiment, the sleeve element 540 is cut lengthwise.
[0082] Referring to the step 1040 of the method 1000, in an
embodiment, the sleeve element 540 is wrapped around the electrical
cable 566.
[0083] Referring to the step 1045 of the method 1000, in an
embodiment, the flat outer surface portions 542 and 544 are aligned
to the flat portions of the tip assembly 102. The alignment is
described in greater detail herein.
[0084] Referring to the step 1050 of the method 1000 and FIG. 16,
in an embodiment, thermal reflow is applied to the sleeve element
540 to bond the sleeve element 540 to the tip assembly 102, the
crown element 520, and the flexible elongate member 108. In FIG.
16, the bonding forms a joint 1610 between the tip assembly 102 and
the flexible elongate member 108. As described above, the sleeve
element 540 is composed of a material similar to the materials of
the flexible elongate member 108 and the tip assembly 102 while the
crown element 520 is composed of a dissimilar material that is
thermoset. Thus, the thermal reflow can fuse the sleeve element 540
the flexible elongate member 108 and the tip assembly 102 together
while the crown element 520 is embedded within the fused material.
As such, the sleeve element 540 can fill the gap and/or space at
the joint 1610. The sleeve element 540 can prevent collapse at the
joint 1610 after the reflowing of different parts. In addition, the
sleeve element 540 functions as a stopper in adding adhesive to the
joint 1610 to maintain adhesive level at the surface of the joint.
Further, the sleeve element 540 can increase the tensile strength
of the joint 1610. In some embodiments, the crown element 520 and
the sleeve element 540 are concentrically aligned to a primary
lumen of the flexible elongate member 108.
[0085] The crown element 520 and the sleeve element 540 provide
several benefits. The crown element 520 provides connection
security and stability for individual pullwire segments 721, 722,
741, and 742 when the pullwire segments 721, 722, 741, or 742 is
actuated in a proximal direction to deflect the tip assembly 102
and the distal portion 104 in a corresponding direction. In
addition, the anchoring of the pullwires 700 and 740 at the posts
528 and 529, respectively, allow actuations of the pullwire
segments 721, 722, 741, and 742 to provide consistent deflection
angles. The holes 530 allow for bonding of the sleeve element 540
to the crown element 520 during the thermal reflow, and thus
increasing the tensile strength. Further, the crown element 520 is
shaped with rounded edges to prevent breakage of the pullwires 700
and 740 over actuations or increase the lifetime of the ICE device
110. The sleeve element 540 is shaped with the flat outer surface
portions 542 and 544 to allow for easy, precise, and consistent
alignment of the pullwires 700 and 740 to the imaging core 562.
Thus, the employment of the sleeve element 540 allow for consistent
angle of articulations. In addition, the sleeve element 540 can
improve tensile strength at the joint between the tip assembly 102
and the flexible elongate member 108.
[0086] FIG. 17 is a side view of a tip member 1700 according to
embodiments of the present disclosure. The tip member 1700 can be
employed by the tip assembly 102 in place of the tip member 560.
The tip member 1700 has a tubular body 1728 with a closed round
distal tip 1720 and an opened proximal end 1732. The tip member
1700 includes a distal portion 1702, a tapered portion 1704, and a
proximal portion 1706 coupled in order from the closed round distal
tip 1720 to the opened proximal end 1732. The tip member 1700
includes a curved bottom outer wall 1734 coupled to a proximal
curved top outer wall 1730 at the proximal portion 1706 that
smoothly transitions into a distal flat top outer wall 1722 at the
distal portion 1702. The smooth radius transition at the tapered
portion 1704 eliminates the need of a perpendicular surface to join
the distal flat top outer wall 1722 and the proximal curved top
outer wall 1730. As such, the outer geometry of the tip member 1700
reduces friction and provides smooth surfaces to avoid catching on
tissue structures when the tip member 1700 traverses through a
patient body and reduces trauma to the patient. In some
embodiments, the tip member 1700 can additionally be treated with a
hydrophilic material to further reduce friction.
[0087] The tubular body 1728 can be composed of a thermoplastic
elastomer material or any suitable biocompatible material that has
acoustic impedance matching to blood within a vessel of a patient
body when in use. In an embodiment, the tip member 1700 is
constructed from a polyether block amide. For example, the
polyether block amide can be a thermoplastic elastomer comprising a
flexible polyether and rigid polyimide, such as Pebax.RTM. 3533 SA
01 MED. Dimensions of the tip member 1700 can vary in different
embodiments. Dimensions of the tip member 1700 can vary in
different embodiments. In some embodiments, the tip member 1700 can
include a length 1714 between about 15 mm to about 30 mm. The
distal flat top outer wall 1722 can extend a length 1712 between
about 5 mm to about 15 mm. In this regard, the flat top outer wall
1722 can define all or at least a portion of an imaging window for
an ultrasound transducer array positioned within the tip member
1700. The tip member 1700 can include a height 1710 proportional to
the outer diameter 1711 of the tip member 1700. In some embodiment,
the height 1710 is at least about 50% of the outer diameter 1711,
with some particular embodiments between about 50% to about 75% of
the outer diameter 1711. The tapered portion 1704 can extend a
length 1716 between about 0.5 mm to about 2 mm and tapers at an
angle 1718 between about 15 degrees to about 75 degrees relative to
a central longitudinal axis of the tip member 1700.
[0088] FIG. 18 is a side perspective view of the tip member 1700
according to embodiments of the present disclosure. The tip member
1700 includes an inner cavity 1800 having an interface portion
1846, an alignment portion 1844, and a receiving portion 1842
coupled in order from the opened proximal end 1732 towards the
closed round distal tip 1720. In addition, the inner cavity 1800
includes a chamber 1834 adjacent and distal to the receiving
portion 1842 used for accommodating kerf seal as described in
greater detail herein.
[0089] The interface portion 1846 is sized and shaped to couple to
the flexible elongate member 108, for example, via the sleeve
element 540. The alignment portion 1844 is sized and shaped to
align to the sleeve element 540 or any suitable connecting member.
In an embodiment, the alignment portion 1844 is molded to form
alignment members 1830 and 1832 along an inner wall portion of the
inner cavity 1800. In an embodiment, the alignment members 1830 and
1832 are configured to have first keyed surfaces inter-engaging
with second keyed surfaces (e.g., flat outer surface portions 542
and 544) of the sleeve element 540. Accordingly, the distal portion
of the flexible elongate member can include a keyed structure
configured to mate with a proximal section of an inner lumen of the
tip member in a predefined orientation.
[0090] The receiving portion 1842 is sized and shaped to receive
the imaging core 562. The geometry of the receiving portion 1842 is
configured to facilitate the alignment and positioning of the
imaging core 562. The receiving portion 1842 includes a proximal
curved top inner wall 1828 that smoothly transitions into a distal
flat top inner wall 1826. The proximal curved top inner wall 1828
is opposite the proximal curved top outer wall 1730 and the distal
flat top inner wall 1826 is opposite the distal flat top outer wall
1722. In an embodiment, the receiving portion 1842 is molded to
form a guide member 1820 having a stepped ledge with a first step
1822 and a second step 1824 extending longitudinally along a
sidewall portion of the receiving portion 1842. The receiving
portion 1842 can include another guide member 1850 (shown in FIG.
19) similar to the guide member 1820 extending longitudinally along
a radially opposite sidewall portion of the receiving portion 1842.
The distal flat top inner wall 1826 and the guide members 1820 and
1850 restrict the positioning of the imaging core 562 within the
receiving portion 1842. In an embodiment, the imaging core 562
includes an array of ultrasound transducer elements and is
positioned such that ultrasonic waves propagates towards and
through the distal flat top inner wall 1826 and the distal flat top
outer wall 1722 as shown by the dashed arrows and described in
greater details herein. The alignment members 1830 and 1832 are
positioned in a pre-defined relation to an orientation of the
imaging core 562.
[0091] Dimensions of the tip member 1700 can vary in different
embodiments. In some embodiments, the tip member 1700 includes a
uniform thickness 1810 between the distal flat top inner wall 1826
and the distal flat top outer wall 1722 of less than 200 microns
such that distortion such as reflection and attenuation of the
ultrasonic waves may be minimized. The receiving portion 1842 can
extend a length 1812 between about 10 mm to about 28 mm. The
alignment portion 1844 can extend a length 1814 between about 1 mm
to about 5 mm. The interface portion 1846 can extend a length 1816
between about 1 mm to about 5 mm.
[0092] FIG. 19 is a cross-sectional view of the tip member 1700
taken along the line 1801 of FIG. 18 according to embodiments of
the present disclosure. FIG. 19 illustrates the opened proximal end
1732 with interface portion 1846 of the inner cavity 1800.
Dimensions of the opened proximal end 1732 can vary in different
embodiments. In some embodiments, the proximal opened end 1732 has
a substantially circular shape. The outer diameter 1711 and the
inner diameter 1713 may be sized to match the body of a catheter
shaft (e.g., the flexible elongate member 108) such that the tip
member 1700 can be coupled to the catheter shaft. For example, a
catheter shaft body between about 8 FR and about 12 FR may have a
wall thickness between about 100 microns and about 400 microns. To
couple to such a catheter shaft, the outer diameter 1711 may be
between about 8 FR and about 12 FR and a difference between outer
diameter 1711 and the inner diameter 1713 may be between about 100
microns and about 400 microns.
[0093] FIG. 20 is a cross-sectional view of the tip member 1700
taken along the line 1802 of FIG. 18 according to embodiments of
the present disclosure. FIG. 20 illustrates the alignment portion
1844 of the inner cavity 1800. The tip member 1700 is molded to
form the alignment members 1830 and 1832 along portions of the
inner wall of the alignment portion 1844. For example, the
alignment members 1830 and 1832 are ledges extending transversely
across the portions of the inner wall and positioned radially
opposite of each other. Each ledge has a flat surface 2020 about
perpendicular to the ultrasonic beam propagate direction of the
imaging core 562. Dimensions of the alignment members 1830 and 1832
can vary in different embodiments. For example, the alignment
members 1830 and 1832 may be shaped and sized to adapt to the
sleeve element 540 (e.g., the flat outer surface portions 542 and
544) such that the sleeve element 540 and the tip member 1700 may
be aligned by inter-engaging the alignment members 1830 and 1832
with the flat outer surface portions 542 and 544.
[0094] FIG. 21 is a cross-sectional view of the tip member 1700
taken along the line 1803 according to embodiments of the present
disclosure. FIG. 21 illustrates the receiving portion 1842 of the
inner cavity 1800, where the tip member 1700 has the proximal
curved top outer wall 1730 and the proximal curved top inner wall
1828. The tip member 1700 is molded to form the guide members 1820
and 1850 along portions of the inner wall of the receiving portion
1842. The guide members 1820 and 1850 are positioned radially
opposite of each other within the receiving portion 1842. The guide
member 1820 includes the step ledge with the first step 1822 and
the second step 1824. Similarly, the guide member 1850 includes a
step ledge with a first step 1852 and a second step 1854. In
addition, the tip member 1700 is molded to form a raised U-shaped
bottom inner wall 1856 extending longitudinally along the receiving
portion 1842 and coupled to the guide members 1820 and 1850. As
described in greater detail herein, the guide members 1820 and 1850
restrict the positioning of the imaging core 562 (not shown).
Dimensions of the guide members 1820 and 1850 and the raised
U-shaped bottom inner wall 1856 can vary in different embodiments.
For example, the dimensions of the guide members 1820 and 1850 and
the separation distance 2112 between the guide members 1820 and
1850 are shaped and sized to accommodate the imaging core 562. The
wall thickness of the raised U-shaped bottom inner wall 1856 is
configured to minimize acoustic attenuation.
[0095] FIG. 22 is a cross-sectional view of the tip member 1700
taken along the line 1804 according to embodiments of the present
disclosure. FIG. 22 illustrates the receiving portion 1842 of the
inner cavity 1800, where the tip member 1700 has the distal flat
top outer wall 1722 and the distal flat top inner wall 1826. The
guide members 1820 and 1850 and the distal flat top inner wall 1826
restrict the positioning of the imaging core 562. For example, the
imaging core 562 can be positioned in the tip member 1700 guided by
the guide members 1820 and 1850 and the distal flat top inner wall
1826 as shown by the dashed box. The guide members 1820 and 1850
restrict the positioning of the imaging core 562 along a first axis
and in a first direction along a second axis about perpendicular to
the first axis. In FIG. 22, the first axis is shown as the x-axis
and the second axis is shown as the y-axis. The distal flat top
inner wall 1826 restricts the positioning of the imaging core 562
in an opposite direction along the second axis. As described above,
the tip member 1700 is sized such that the thickness 1810 between
the distal flat top outer wall 1722 and the distal flat top inner
wall 1826 is less than 200 micron to minimize distortions such as
reflections and/or deflections of ultrasonic waves (dashed arrows)
produced by the imaging core 562 during operation.
[0096] FIG. 23 is a back perspective view of the tip member 1700
according to embodiments of the present disclosure. FIG. 23
illustrates the structure of the inner cavity 1800 viewing from the
opened proximal end 1732 as shown by the line 1801. As shown, the
inner cavity 1800 includes the alignment member 1830 and 1832, the
raised U-shaped bottom inner wall 1856, the guide members 1820 and
1850, and the distal flat top inner wall 1826. The raised U-shaped
bottom inner wall 1856 is adjacent and distal to the alignment
member 1832 and coupled to the guide members 1820 and 1850.
[0097] FIG. 24 is a back perspective view of the tip member 1700
with the imaging core 562 in position according to embodiments of
the present disclosure. FIG. 24 illustrates the positioning of the
imaging core 562 in the inner cavity 1800 viewing from the opened
proximal end 1732 as shown by the line 1801. The imaging core 562
is encased within the inner cavity 1800 guided by the guide members
1820 and 1850 and the distal flat top inner wall 1826. The imaging
core 562 can include a transducer circuit layer 2414 embedded
between an acoustic stack 2412 and a backing material layer 2416.
The transducer circuit layer 2414 includes ultrasound transducer
elements and associated circuitry. The acoustic stack 2412 is
composed of materials acoustically matched to the ultrasound
transducer elements, the transmission medium, and the target tissue
for imaging. The backing material layer 2416 is composed of an
acoustically absorptive material so that the backing material layer
2416 can absorb or deaden the ultrasonic waves coming from the back
of the transducer circuit layer 2414. For example, the acoustic
stack 2412 can include materials such as PZT, single crystal, CMUT,
PMUT, etc. and the backing material layer 2416 can include an epoxy
material. The acoustic stack 2412 is positioned almost against the
distal flat top inner wall 1826, creating a thin bond line to
further minimize acoustic distortion of the ultrasonic waves. The
spaces of the inner cavity 1800 are filled with an encapsulating
material to enclose the imaging core 562. For example, the
encapsulating material may include polydimethylsiloxane (PDMS),
polyurethane, ultraviolet (UV) adhesives, or any suitable material
that have desirable characteristics such as acoustic properties,
bonding strength, and ease to work with during manufacturing. In
some embodiments, the acoustic stack 2412 includes non-filled air
kerfs, for example, along a perimeter of the acoustic stack 2412.
In such embodiments, the perimeter of the acoustic stack 2412 is
sealed with a sealing material such as an UV adhesive to seal the
non-filled air kerfs prior to filling the inner cavity 1800 with
the encapsulating material. The chamber 1834 shown in FIG. 18 can
be used to accommodate the sealing material.
[0098] FIG. 25 is a cross-sectional side view of the imaging core
562 taken along the line 2402 of FIG. 24 according to embodiments
of the present disclosure. The transducer circuit layer 2414
includes an array of ultrasound transducer elements 2510 coupled to
one or more multiplexer chips 2512, for example, via conductive
traces and/or associated circuitry. In some embodiments, the number
of ultrasound transducer elements 2510 may be 8, 16, 32, 64, or any
suitable number. The ultrasound transducer elements 2510 are
composed of piezoelectric material. Exemplary transducers for ICE
have a typical thickness of approximately 0.28 mm in the
piezoelectric material to enable an 8 megahertz (MHz) ultrasound
signal to be generated and transmitted at a typical velocity of
1500 meter per second (m/sec) through blood. The transducer
thickness can be of various thicknesses ranging approximately from
0.56 mm to 0.19 mm to generate sufficient penetration depth in
tissue imaging. In general, the thickness of the transducers can be
adjusted for the frequency of sound in the transmission medium for
the desired penetration depth in any tissue imaging. Image
intensity can be adjusted by driving voltage on the
transducers.
[0099] The multiplexer chips 2512 multiplex control signals, for
example, generated by the processing system 130, and transfer the
control signals to corresponding ultrasound transducer elements
2510. The controls signals can control the emission of ultrasound
pulses and/or the reception of echo signals. In the reverse
direction, the multiplexer chips 2512 multiplexes echo signals
reflected by target tissue and received by the ultrasound
transducer elements 2510 multiplexer chips 2512 and transfer the
received echo signals, for example, to the processing system 130
for processing and/or display.
[0100] FIG. 26 is a perspective view of the tip assembly 102 and
the sleeve element 540 positioned for coupling according to
embodiments of the present disclosure. The tip assembly 102 is
illustrated with the imaging core 562 in position within the tip
member 1700. The imaging core 562 is coupled to the electrical
cable 566 via the electrical interconnection 564. The electrical
cable 566 extends through the alignment portion 1844 and the
interface portion 1846 of the inner cavity 1800 and sleeve element
540. The electrical cable 566 can further extend through the
flexible elongate member 108 as shown in FIG. 5. During
manufacturing, the interface portion 1846 can extend over and cover
a portion of the sleeve element 540, the crown element 520, and the
flexible elongate member 108, thus improving the bonding
strength.
[0101] As shown, the tip member 1700 is oriented such that the
alignment members 1830 and 1832 are aligned to the flat outer
surface portions 542 and 544 of the sleeve element 540. As
described above, the sleeve element 540 includes the flat outer
surface portions 542 and 544 and the slots 551 and 552, which are
configured to couple to the crown element 520 in a particular
orientation associated with the positioning of the pullwires 700
and 740. Thus, the sleeve element 540, the alignment members 1830
and 1832, and the crown element 520 can be conjunctively designed
to allow coupling of the sleeve element 540, the alignment members
1830 and 1832, and the crown element 520 in a particular
orientation. As such, the sleeve element 540, the alignment members
1830 and 1832, and the crown element 520 can be consistently
aligned during manufacturing without additional alignment
measurement or adjustment. Since the alignment members 1830 and
1832 are oriented in a pre-defined relation with the ultrasound
beam propagation direction of the imaging core 562 and the
pullwires 700 and 740 are configured to provide steering of the tip
assembly 102, the actuations of the pullwires 700 and 740 can
provide consistent articulation view for imaging. It should be
noted that the alignment keying of the sleeve element 540 and the
alignment members 1830 and 1832 can be alternatively configured as
determined by a person of ordinary skill in the art to achieve
similar functionalities.
[0102] The configuration and structure of the tip member 1700
described above provide several benefits such as safe and easy
delivery for catheterization, improved tensile strength for
steering or navigation, consistent or automatic alignment, and
improved image quality. For example, the outer geometry of the tip
member 1700 is configured to provide smooth surfaces and smooth
edges with small radii. The smooth edges reduce friction when the
tip member 1700 traverses a vessel during insertion. The smooth
surfaces prevent tears and/or damages to tissue structures during
the insertion. The smooth, radius transition from the proximal
curved top outer wall 1730 to the distal flat top outer wall 1722
ensure that there are no ledges that can catch on outer features
during the insertion. In addition, the smooth edges and smooth
surfaces can facilitate crossing of a septum or other anatomical
feature during a catheterization procedure. The material type and
the wall thickness (e.g., the uniform thickness 1810) of the tip
member 1700 are selected to minimize acoustic distortion,
attenuation, and/or reflection. The internal geometry of the tip
member 1700 is configured to facilitate alignment during
manufacturing. As described, the alignment members 1830 and 1832
provide consistent and predictable alignment between the imaging
core 562 and the pullwires 700 and 740. The tip member 1700 can
also include other features, for example, a guidewire lumen, holes,
or other geometry to accommodate additional devices or features
such as pressure sensors, drug delivery mechanisms, and/or any
suitable interventional features.
[0103] FIGS. 27-30 illustrate alternative tip member configurations
that can provide substantially similar benefits as the tip member
1700. FIG. 27 is a side perspective view of a tip member 2700
according to embodiments of the present disclosure. The tip member
2700 can be employed by the tip assembly 102. The tip member 2700
has a tubular body 2742 with a closed round distal end 2720 and an
opened proximal end 2728. The tip member 2700 includes a distal
portion 2702 and a proximal portion 2704. The tip member 2700
includes a curved outer wall 2724. For example, the tip member 2700
has at least a substantially uniform external circular or
cross-sectional profile. In such manner, the diameter or
cross-section of the tip member may be at least substantially
uniform between the closed distal end and the open proximal end. In
some embodiments, the diameter of the tip member is the same
between the closed distal end and open proximal end is the same. In
other embodiments, there may be slight change in the diameter (e.g.
1-25% such that it is substantially uniform. For example, the
diameter or cross-section may slightly decrease in size as the tip
member extends to the distal closed end, providing a tapered shape.
Ideally, there is only 1-10% variability in the tip member's
diameter or cross-section. In particular embodiments, there is only
1%, 2%, 3%, 4%, or up to 5% variability in the substantially
uniform diameter or cross-section. In some embodiments, the curved
outer wall 2724 can be designed to provide a lens effect to focus
ultrasonic waves. The tubular body 2742 can be constructed from
similar materials as the tubular body 1728 of the tip member 1700
member.
[0104] The tip member 2700 includes an inner cavity 2730 extending
from the closed proximal end 2728 towards the closed round distal
end 2720. The inner cavity 2730 is configured to receive the
imaging core 562. The inner cavity 2730 includes a proximal curved
top inner wall 2726 at the proximal portion 2704 and a distal flat
top inner wall 2722 at the distal portion 2702. The inner cavity
2730 includes a curved bottom inner wall 2738 coupled to the
proximal curved top inner wall 2726 and the distal flat top inner
wall 2722. The inner cavity 2730 is molded to form a pair of rails
2732 and 2734 extending along a sidewall portion of the inner
cavity 2730 from the proximal opened end 2728 towards the closed
round distal end 2720. The rails 2732 and 2734 are
circumferentially spaced apart from each other forming a space for
positioning the imaging core 562. The inner cavity 2730 further
includes another pair of rails 2752 and 2754 (shown in FIG. 28)
similar to the rails 2732 and 2734 extending longitudinally along a
radially opposite sidewall portion of the inner cavity 2730. Thus,
the rails 2732, 2734, 2752, and 2754 operate as guide members to
restrict the positioning of the imaging core 562. For example, the
imaging core 562 is positioned such that the ultrasound transducer
elements 2510 emit ultrasonic waves towards and through the distal
flat top inner wall 2722 and curved outer wall 2724 at the distal
portion 2702 as shown by the dashed arrows. Dimensions of the tip
member 2700 can be substantially similar to the tip member 1700,
but the wall thickness 2710 at the distal portion 2702 is greater
than 200 microns. For example, the wall thickness 2710 can be
between about 25% and about 50% of the outer diameter 2712 of the
tip member 2700.
[0105] FIG. 28 is a back perspective view of the tip member 2700
with the imaging core 562 in position according to embodiments of
the present disclosure. FIG. 28 illustrates the positioning of the
imaging core 562 in the inner cavity 2730 viewing from the opened
proximal end 2728 as shown by the line 2701. The imaging core 562
is encased within the inner cavity 2730 guided by the rails 2732,
2734, 2752, and 2754 along a first axis and a second axis about
perpendicular to the first axis. In FIG. 28, the first axis is
shown as the x-axis and the second axis is shown as the y-axis. The
positioning of the imaging core 562 along the z-axis is restricted
by the farthest distal end of the inner cavity 2730. The spaces
between the inner cavity 2730 and the imaging core 562 are filled
with similar encapsulating material as used for the inner cavity
1800 of the tip member 1700. The tip member 2700 can further
include alignment members similar to the alignment members 1830 and
1832 to facilitate alignment with the sleeve element 540, the crown
element 520, and the flexible elongate member 108.
[0106] FIG. 29 is a side perspective view of a tip member 2900
according to embodiments of the present disclosure. The tip member
2900 can be employed by the tip assembly 102. The tip member 2900
is similar to the tip member 2700, but has a different internal
geometry. The tip member 2900 has a tubular body 2942 with a closed
round distal end 2920 and an opened proximal end 2928. The tip
member 2900 includes a distal portion 2902 and a proximal portion
2904. The tip member 2900 includes a curved outer wall 2924. The
tubular body 2942 can be constructed from similar materials as the
tubular body 1728 of the tip member 1700 member and the tubular
body 2742 of the tip member 2700 member.
[0107] The tip member 2900 includes an inner cavity 2930 extending
from the closed proximal end 2928 towards the closed round distal
end 2920. The inner cavity 2930 is configured to receive the
imaging core 562. The inner cavity 2930 includes a curved inner
wall 2926. The inner cavity 2930 is molded to form a pair of rails
2932 and 2934 extending along a sidewall portion of the inner
cavity 2930 from the proximal opened end 2928 towards the closed
round distal end 2920. The rails 2932 and 2934 are
circumferentially spaced apart from each other forming a space for
positioning the imaging core 562. The inner cavity 2930 further
includes another pair of rails 2952 and 2954 (shown in FIG. 30)
similar to the rails 2932 and 2934 extending longitudinally along a
radially opposite sidewall portion of the inner cavity 2930. Thus,
the rails 2932, 2934, 2952, and 2954 operate as guide members to
restrict the positioning of the imaging core 562. For example, the
imaging core 562 is positioned such that the ultrasound transducer
elements 2510 emit ultrasonic waves towards and through a portion
of the curved inner wall 2926 and a portion of curved outer wall
2924 at the distal portion 2902 as shown by the dashed arrows.
[0108] FIG. 30 is a back perspective view of the tip member 2900
with the imaging core 562 in position according to embodiments of
the present disclosure. FIG. 30 illustrates the positioning of the
imaging core 562 in the inner cavity 2930 viewing from the opened
proximal end 2928 as shown by the line 2901. The imaging core 562
is encased within the inner cavity 2930 guided by the rails 2932,
2934, 2952, and 2954 along a first axis and a second axis about
perpendicular to the first axis. In FIG. 28, the first axis is
shown as the x-axis and the second axis is shown as the y-axis. The
positioning of the imaging core 562 along the z-axis is restricted
by the farthest distal end of the inner cavity 2930. The spaces
between the inner cavity 2930 and the imaging core 562 are filled
with similar encapsulating material as used for the inner cavity
1800 of the tip member 1700 and the inner cavity 2730 of the tip
member 2700. The tip member 2900 can further include alignment
members similar to the alignment members 1830 and 1832 to provide
consistent alignment with the sleeve element 540, the crown element
520, and the flexible elongate member 108.
[0109] FIGS. 31 and 32 illustrate a lined variable braided
differential durometer multi-lumen catheter shaft 3100. The
catheter shaft 3100 can be employed by the ICE device 110 in place
of the flexible elongate member 108. FIG. 31 is a cross-sectional
view of the lined variable braided differential durometer
multi-lumen catheter shaft 3100 taken along a transverse axis of
the catheter shaft 3100 according to embodiments of the present
disclosure. FIG. 32 is a cross-sectional longitudinal view of the
lined variable braided differential durometer multi-lumen catheter
shaft 3100 taken along the line 3101 of FIG. 31 according to
embodiments of the present disclosure. The catheter shaft 3100 has
a distal end 3202 and a proximal end 3204. The catheter shaft 3100
is tubular in shape with a tubular wall 3102 and a primary lumen
3108. The primary lumen 3108 extends between the distal end 3202
and the proximal end 3204, for example, along a central
longitudinal axis of the catheter shaft 3100.
[0110] The tubular wall 3102 is composed of a high durometer
polymeric material at a distal segment 3206 and a low durometer
polymeric material at a proximal segment 3208. For example, the
high durometer polymeric material may have a durometer between 63
D-80 D and include materials such as a polyether block amide (e.g.,
Pebax.RTM. 72 D) or a suitable nylon. The low durometer polymeric
material may have a durometer between 30 D to 55 D and include
materials such as a polyether block amide (e.g., Pebax.RTM. 35 D or
Pebax.RTM. 45 D) or a suitable nylon. The highly differing
durometer of the tubular wall 3102 between the distal segment 3206
and the proximal segment 3208 creates a sharp transition or a high
stiff-to-flex ratio in the catheter shaft 3100. Thus, the catheter
shaft 3100 can be relatively rigid at the proximal segment 3208,
but substantially pliable or flexible at the distal segment 3206.
The steerability of the catheter shaft 3100, the amount of force to
bend the catheter shaft 3100, and the locality of the bend force
and/or actuations may depend on the durometer of the catheter shaft
3100. The sharp transition may improve the steerability, the amount
of force, and/or the locality of the force when the catheter shaft
3100 is in use.
[0111] The catheter shaft 3100 further includes a plurality of
secondary lumens 3106 extending longitudinally through a length of
the tubular wall 3102. The primary lumen has a rounded cross-shaped
cross-sectional profile. The secondary lumens 3106 are shaped and
sized to accommodate pullwires such as the pullwires 507, 700, and
740. Thus, the secondary lumens 3106 are also referred to as
pullwire lumens. The secondary lumens 3106 are positioned within
the tubular wall 3102 radially spaced apart by an angle 3180 of
about 90 degrees. The primary lumen has a cross-shaped
cross-sectional profile. The arms 3110 of the cross-shaped cross
section form recesses that can anchor the angular positions of the
secondary lumens 3106. For example, the secondary lumens 3106 are
positioned between adjacent arms 3110 during manufacturing as
described in greater detail herein. The primary lumen 3108 and the
secondary lumens 3106 can be lined with a lubricious lining
material (not shown) such as a polytetrafluoroethylene (PTFE)
material. The lining material creates frictionless surfaces for
threading, delivery, and actuations of pullwires or any other
suitable diagnostic sensor assembly. In addition, the lining
material can function as a support structure to prevent the primary
lumen 3108 and the secondary lumens 3106 from collapsing. Further,
the lining material can function as a barrier to protect abrasion
caused by the frequent shifting or actuations of the pullwires
and/or threading of the other diagnostic sensor assembly.
[0112] The catheter shaft 3100 further includes a braided layer
3104 embedded within the tubular wall 3102. The braided layer 3104
includes a distal portion 3212, a proximal portion 3216, and a
transition portion 3214 between the distal portion 3212 and the
proximal portion 3216. The braided layer 3104 can be composed of
any suitable material and geometry. For example, the braided layer
3104 may include stainless steel flat wires, which may provide
optimal usage of radial space and additional strength. The braided
layer 3104 has braids with pitches that vary along a length of the
tubular wall 3102. The braids can include any suitable braid
pattern. The braid pattern may be selected to improve torque
transmission (e.g., a 1:1 ratio from the proximal end 3204 to the
distal end 3202), pushability, and/or kink resistance.
[0113] The braids at the distal portion 3212 are configured to have
a higher per inch count (PIC) than the braids at the proximal
portion 3216, for example, by about two times. The higher PIC at
the distal portion 3212 provides a great flexibility to the distal
segment 3206. The lower PIC at the proximal portion 3216 creates a
stiffer support for the proximal segment 3208. For example, the
distal portion 3212 has a first PIC, the proximal portion 3216 has
a second PIC, and the transition portion 3214 has a varying PIC
that varies smoothly from the first PIC to the second PIC. As
shown, the distal portion 3212 of the braided layer 3104 is aligned
to the distal segment 3206 of the catheter shaft 3100, the proximal
portion 3216 of the braided layer 3104 is aligned to the proximal
segment 3208 of the catheter shaft 3100, and the transition portion
3214 extends across a coupling point at which the low durometer
distal segment 3206 meets the high durometer proximal segment 3208
as shown by the line 3201. The transition portion 3214 can extend a
length 3280, for example, between about 5 mm to about 20 mm. The
smooth varying braid pitches in the short transition portion 3214
can alleviate the weak kink point resulting from the abrupt
transition between the low durometer distal segment 3206 and the
high durometer proximal segment 3208.
[0114] Dimensions of the catheter shaft 3100 can vary in different
embodiments. In some embodiments, the catheter shaft 3100 may be a
9 Fr catheter. Thus, the catheter shaft 3100 can have an outer
diameter 3182 of about 3 mm. The distal segment 3206 can have a
length 3282 between about 70 mm to about 81 mm. The length 3282 may
vary based on a required bend radius for the catheter shaft 3100.
The proximal segment 3208 can have a length 3282 between about 872
mm to 877 mm. The dimensions of the cross-shaped primary lumen 1308
can be sized to allow components (e.g., a printed circuit board
(PCB) and/or a coaxial cable) to be thread through the lumen 1308
during assembly instead of using the coaxial cable as an anchor as
in some configurations, and thus may improve handling
responsiveness during operation. The low durometer material used in
in the distal segment 3206 and the braided layer 3104 allows the
catheter shaft 3100 to deflect up to a bend radius (e.g., the bend
radius 305) of between about 13 mm to about 14 mm instead of about
27 mm to about 28 mm.
[0115] A method of manufacturing the catheter shaft 3100 is
described with reference made to FIGS. 33-35. FIG. 33 is a
perspective view of a multi-lumen inner extrusion 3300 in a stage
of manufacturing according to embodiments of the present
disclosure. The inner extrusion 3300 includes a high durometer
proximal portion 3320 of a first material (e.g., Pebax.RTM. 72 D)
and a low durometer distal portion 3310 of a second material (e.g.,
Pebax.RTM. 35 D or Pebax.RTM. 45 D). The inner extrusion 3300
includes a primary lumen 3331 (e.g., primary lumen 3108) and a
plurality of secondary lumens 3332 (e.g., secondary lumens 3106)
extending between the high durometer proximal portion 3320 and the
low durometer distal portion 3310.
[0116] FIG. 34 is a perspective view of a braid reinforced inner
extrusion 3400 in a stage of manufacturing according to embodiments
of the present disclosure. As shown, a braided layer 3410 (e.g.,
the braided layer 3104) is formed over an outer surface of the
inner extrusion 3300. The braided layer 3410 has a first braid
portion 3416 (e.g., the proximal portion 3216) with a first braid
pitch (e.g., with a first PIC) over the high durometer proximal
portion 3320. The braided layer 3410 has a second braid portion
3412 (e.g., the distal portion 3212) with a second braid pitch
(e.g., with a second PIC) over the low durometer distal portion
3310. The braided layer 3410 has a third braid portion 3414 (e.g.,
the transition portion 3214) with variable braid pitches (e.g.,
varying between the first PIC and the second PIC) across a
transition between the high durometer proximal portion 3320 and the
low durometer distal portion 3310.
[0117] FIG. 35 is a perspective view of a single-lumen outer
extrusion 3500 inserted over the braided inner extrusion 3400 in a
stage of manufacturing according to embodiments of the present
disclosure. The outer extrusion 3500 includes a high durometer
proximal portion 3520 of a first material (e.g., Pebax.RTM. 72 D)
and a low durometer distal portion 3510 of a second material (e.g.,
Pebax.RTM. 35 D or Pebax.RTM. 45 D). The inner extrusion 3300 and
the outer extrusion 3500 form the tubular wall 3102 of the catheter
shaft 3100. The braided layer 3410 corresponds to the braided layer
3104 embedded within the tubular wall 3102.
[0118] After forming the catheter shaft 3100, pullwires such as the
pullwires 700 and 740 may be thread through the secondary lumens
3106 according to predetermined orientations for providing the
left, right, anterior, and posterior views. The distal end 3202 of
the catheter shaft 3100 may be coupled to a tip assembly such as
the tip assembly 102. For example, the coupling may include
terminating or enclosing the braided element 3104 in a braid
containment such as the braid containment 502. In addition, the
coupling can include forming an interconnection as shown in FIG. 5.
An electrical cable such as the electrical cable 566 connecting to
the tip assembly may be threaded through the primary lumen 3108.
The proximal end 3204 of the catheter shaft 3100 may be coupled to
a steering control handle such as the handle 120.
[0119] The configuration of the lined variable braided differential
durometer multi-lumen catheter shaft 3100 provides several benefits
such as kink resistance, flexibility, high torquability,
durability, and consistent alignment and articulations. The sharp
transition between the low durometer distal segment 3206 and the
high durometer proximal segment 3208 and the short transition
portion 3214 of the braided element 3104 with varying PIC braids
provide the kink resistance. The low durometer distal segment 3206,
the high durometer proximal segment 3208, the high PIC braids at
the distal portion 3212, and the low PIC braids at the proximal
portion 3216 provide flexibility at the distal segment 3206 and
rigid support at the proximal segment 3208. The cross-shaped
cross-sectional profile of the primary lumen 3108 functions as an
alignment agent to align the pullwire lumens or the secondary
lumens 3106 such that pullwires such as the pullwires 507, 700, and
740 threaded through the secondary lumens 3106 can provide
consistent articulation views under actuations. The primary lumen
3108 and the secondary lumens 3106 are lined with a lining material
to provide frictionless surfaces, which may improve durability over
multiple usages. Materials of the tubular wall 3102 and the braided
element 3104 are selected to improve mechanical characteristics
(e.g., the steerability of the catheter shaft 3100).
[0120] Persons skilled in the art will 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.
* * * * *