U.S. patent application number 16/516074 was filed with the patent office on 2019-11-07 for catheter with flow diverter and force sensor.
The applicant listed for this patent is Biosense Webster (Israel) Ltd.. Invention is credited to Christopher Thomas Beeckler, Tom Allen Ditter, Assaf Govari, Rowan Olund Hettel.
Application Number | 20190336210 16/516074 |
Document ID | / |
Family ID | 57714538 |
Filed Date | 2019-11-07 |
United States Patent
Application |
20190336210 |
Kind Code |
A1 |
Beeckler; Christopher Thomas ;
et al. |
November 7, 2019 |
Catheter with Flow Diverter and Force Sensor
Abstract
A catheter probe comprises an insertion tube, and a distal end
with a distal electrode, a force sensor to detect force on the
distal electrode, and an irrigated electrode mounted on a coupling
member of the force sensor, which has a tubular form surrounding a
central space occupied by components, including force sensing
coils. A fluid diverter that passes fluid to the proximal irrigated
electrode is configured as an insert or an integrated projection of
the coupling member, which configuration minimizes its space demand
within the coupling member. Thus, the diameter of the distal end
need not be increased. The fluid diverter has a proximal entry
opening and a distal exit opening connected by a fluid passage with
at least a radial branch and at least an axial branch. The
irrigated electrode is mounted over the distal exit opening to
receive fluid from the fluid passage.
Inventors: |
Beeckler; Christopher Thomas;
(Brea, CA) ; Govari; Assaf; (Haifa, IL) ;
Hettel; Rowan Olund; (Pasadena, CA) ; Ditter; Tom
Allen; (Mission Viejo, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Biosense Webster (Israel) Ltd. |
Yokneam |
|
IL |
|
|
Family ID: |
57714538 |
Appl. No.: |
16/516074 |
Filed: |
July 18, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
14988226 |
Jan 5, 2016 |
10363090 |
|
|
16516074 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61B 2018/00166
20130101; A61B 2018/00351 20130101; A61B 5/6852 20130101; A61B
2018/00744 20130101; A61B 18/1492 20130101; A61B 2018/00755
20130101; A61B 2018/00577 20130101; A61M 25/003 20130101; A61M
25/0043 20130101; A61B 2018/00029 20130101; A61B 2018/00696
20130101; A61B 2218/002 20130101; A61M 25/0029 20130101; A61B 5/061
20130101; A61B 2018/00773 20130101; A61B 5/6885 20130101; A61B
2018/00875 20130101 |
International
Class: |
A61B 18/14 20060101
A61B018/14; A61B 5/00 20060101 A61B005/00; A61B 5/06 20060101
A61B005/06 |
Claims
1. A catheter probe, comprising: an insertion tube defining a
longitudinal axis; a distal electrode; a proximal electrode; a
joint sensing assembly disposed between the insertion tube and the
distal electrode, the joint sensing assembly including a
transmitting coil and a plurality of receiving coils spaced apart
along the longitudinal axis of the insertion tube, a coupling
member having a first portion coupled to the transmitting coil and
a second portion coupled to the plurality of receiving coils, the
second portion of the coupling member having a proximal portion
with a central space and a proximal opening with a slot, a diverter
positioned in the slot, the diverter having a proximal entry
opening and a distal exit opening, the diverter having a fluid
passage with a radial branch and an axial branch; and a first
tubing extending from a proximal end of the insertion tube to the
proximal entry opening of the diverter, the first tubing configured
to supply irrigation fluid to the fluid passage, and the proximal
electrode is mounted on the proximal portion of the joint sensing
assembly and is positioned over the distal exit opening.
2. The catheter probe of claim 1, wherein the diverter is
configured as an insert affixed in the slot.
3. The catheter probe of claim 1, wherein the coupling member
includes a tubular form with a convex outer surface, and the
diverter includes a convex outer surface.
4. The catheter probe of claim 1, wherein the diverter includes an
inner surface with a concavity.
5. The catheter probe of claim 1, wherein the diverter includes an
outer surface with an indent formation that extends around a
peripheral edge of the outer surface.
6. The catheter probe of claim 1, wherein the proximal electrode is
configured with a side wall providing a space gap around the
proximal portion.
7. The catheter probe of claim 1, further comprising an insulating
sheath mounted on the proximal portion and the diverter, the sheath
having a through-hole aligned with the distal exit opening of the
diverter.
8. The catheter probe of claim 1, further comprising a second
tubing extending from the proximal end of the insertion tube to the
distal electrode, the second tubing configured to supply irrigation
fluid to the distal electrode.
9. The catheter probe of claim 1, wherein the transmitting coil and
the plurality of receiving coils are housed in the central
space.
10. The catheter probe of claim 9, wherein the diverter is
positioned in substantially the same axial plane as the receiving
coils, but at a different azimuthal angle.
11. The catheter probe of claim 10, wherein the plurality of
receiving coils include three coils located in the same axial plane
at different azimuthal angles about longitudinal axis, and have
respective axes of symmetry generally parallel to the longitudinal
axis.
12. The catheter probe of claim 11, wherein the three receiving
coils are spaced azimuthally at approximately 120.degree. apart at
the same radial distance from the longitudinal axis.
13. The catheter probe of claim 12, wherein the three receiving
coils generate electrical signals in response to a magnetic field
transmitted by coil 82 in order to measure a displacement of
coupling member parallel to the longitudinal axis as well as to
measure an angular deflection of the coupling member from the
longitudinal axis.
Description
PRIORITY
[0001] This patent application claims the benefit of priority to
prior filed U.S. patent application Ser. No. 14/988,226 filed Jan.
5, 2016, now allowed and issuing as U.S. Pat. No. 10,363,090, which
prior application is incorporated by reference in its entirety into
this application.
FIELD OF INVENTION
[0002] The present invention relates generally to catheters having
electrodes, and specifically to catheters wherein the electrodes
are irrigated.
BACKGROUND OF INVENTION
[0003] Medical procedures involving ablation of the heart may be
used to cure a variety of cardiac arrhythmia, as well as to manage
atrial fibrillation. Such procedures are known in the art. Other
medical procedures using ablation of body tissue, such as treating
varicose veins, are also known in the art. The ablation energy for
these procedures may be in the form of radio-frequency (RF) energy,
which is supplied to the tissue via one or more electrodes of a
catheter used for the procedures.
[0004] The application of the ablation energy to body tissue, if
uncontrolled, may lead to an unwanted increase of temperature of
the tissue. It is consequently important to control the temperature
of the tissue during any medical procedure involving ablation. One
method for control is to irrigate the tissue being ablated.
However, irrigation requires components to deliver fluid from a
proximal end of the catheter to its distal end. With catheter
distal ends having diameters on the order of millimeters, space is
often a primary constraint on the design and configuration of
distal ends that provide for fluid delivery components. Moreover,
with distal ends having tip and ring electrodes, such fluid
delivery components must define fluid pathways that can provide
axial flow and radial flow but occupy minimal space and avoid
interfering with other functional aspects of the distal end, such
as force sensing.
[0005] 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.
SUMMARY OF THE INVENTION
[0006] The present invention includes a catheter probe, comprising
an insertion tube, a distal electrode, and a proximal electrode.
The catheter probe includes a force sensor between the insertion
tube and the distal electrode, the force sensor having a coupling
member with a proximal portion with a central space and a proximal
opening with a slot. The catheter probe further includes a diverter
situated in the slot, the diverter having a proximal entry opening
and a distal exit opening connected by a fluid passage with a
radial branch and an axial branch. A first tubing extends from a
proximal end of the insertion tube to the proximal entry opening of
the diverter, the first tubing configured to supply irrigation
fluid to the fluid passage. Advantageously, the proximal electrode
is mounted on the proximal portion of the coupling member and is
positioned over the distal exit opening to receive irrigation fluid
delivered by the first tubing.
[0007] In some embodiments, the diverter is configured as an insert
affixed in the slot.
[0008] In some embodiments, the coupling member has a tubular form
with a convex outer surface, and the diverter has a corresponding
convex outer surface.
[0009] In some embodiments, the diverter has an inner surface with
a concavity to maximize space and to minimize interference with
components occupying or passing through the central space of the
coupling member.
[0010] In some embodiments, the diverter has an outer surface with
an indent formation that extends around a peripheral edge of the
outer surface, the indent formation engaging with the slot of the
proximal portion of the coupling member.
[0011] In some embodiments, the proximal electrode is configured
with side wall providing a space gap around the proximal portion,
the space gap functioning as a reservoir for irrigation fluid.
[0012] In some embodiments, the catheter probe includes an
insulating sheath mounted on the proximal portion and the diverter,
the sheath having a through-hole aligned with the distal exit
opening of the diverter.
[0013] In some embodiments, a second tubing extending from a
proximal end of the insertion tube to the distal electrode and
through the central space of the coupling member, the second tubing
configured to supply irrigation fluid to the distal electrode.
[0014] In some embodiments, a force sensing coil is housed in the
central space without interference by the diverter.
[0015] In some embodiments, the diverter is positioned in
substantially the same axial plane as the force sensing coil, but
at a different azimuthal angle, to avoid interference with one or
more force sensing coils housed in the central space.
[0016] The present invention is also directed to catheter probe,
comprising an insertion tube, a distal electrode, and a proximal
electrode. The catheter probe includes a force sensor mounted on a
distal end of the insertion tube, the force sensor having a
coupling member with a distal portion, a proximal portion, a
central space, the distal electrode distal of the coupling member,
the proximal electrode mounted on the proximal portion, the force
sensor configured to measure a force on the distal electrode, the
force sensor having an integrated diverter with a fluid passage
connecting a proximal entry opening and a distal exit opening, the
diverter configured as a projection extending inwardly into the
central space from a side wall of the proximal portion of the
coupling member. The catheter probe further includes a first tubing
extending from a proximal end of the insertion tube to the proximal
entry opening. Advantageously, the proximal electrode is positioned
over the distal exit opening to receive irrigation fluid delivered
by the first tubing.
[0017] In some embodiments, a second tubing extends from a proximal
end of the insertion tube to the distal electrode and through the
central space of the coupling member, the second tubing configured
to supply irrigation fluid to the distal electrode.
[0018] In some embodiments, a transmitting coil is housed in the
central space of the distal portion, one or more forcing sensing
coils being responsive to the transmitting coil.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] These and other features and advantages of the present
invention will be better understood by reference to the following
detailed description when considered in conjunction with the
accompanying drawings wherein:
[0020] FIG. 1 is a schematic, pictorial illustration of a catheter
probe ablating system, according to an embodiment of the present
invention;
[0021] FIG. 2 is a schematic cross-section of a distal end of a
catheter probe used in the system having dedicated irrigation
tubes, according to an embodiment of the present invention.
[0022] FIG. 3 is a perspective view of a diverter, according to an
embodiment of the present invention.
[0023] FIG. 4 is a perspective view of a proximal portion of a
coupling member with the diverter of FIG. 3, according to an
embodiment of the present invention.
[0024] FIG. 5 is a perspective view of a distal end of a catheter
probe, with the proximal portion of FIG. 4, according to an
embodiment of the present invention.
[0025] FIG. 6 is the perspective view of the distal end of FIG. 5,
with part(s) broken away.
[0026] FIG. 7 is a perspective view of a proximal portion of a
coupling member with an integrated diverter, according to one
embodiment of the present invention.
[0027] FIG. 8 is a perspective view of a distal end of a catheter
probe, with the proximal portion of FIG. 7, according to another
embodiment of the present invention.
[0028] FIG. 9 is a side schematic view of a proximal portion with
an integrated diverter, according to another embodiment of the
present invention.
[0029] FIG. 10 is a side schematic view of a proximal portion with
an integrated diverter, according to another embodiment of the
present invention.
[0030] FIG. 11 is a side schematic view of a proximal portion with
an integrated diverter, according to another embodiment of the
present invention.
DETAILED DESCRIPTION OF THE INVENTION
Overview
[0031] An embodiment of the present invention provides a catheter
probe which is typically used for a minimally invasive procedure
such as ablation of cardiac tissue. The catheter probe comprises an
insertion tube, which, in order for it to be minimally invasive,
usually has a small outer diameter of approximately 2 mm. At least
one electrode, and typically two or more separate electrodes, are
mounted on the distal end of the insertion tube (the distal end has
approximately the same diameter as the insertion tube).
[0032] Mounted within the distal end is a force sensor, which
measures the force on the distal end when the end contacts tissue.
(Controlling the force enables tissue ablation to be performed more
precisely.) The force sensor may have a tubular form that contacts
an outer sheath of the insertion tube. The force sensor has a
distal central opening, a proximal central opening, and typically
defines a central space therebetween.
[0033] The one or more electrodes have respective sets of
apertures, which are used to supply irrigation fluid to the
electrodes and to body material in the region of the electrodes.
Irrigation tubing supplies the irrigation fluid to the electrode
apertures.
[0034] By using the "empty" region within the force sensor,
including the proximal central opening and the central space, for
the irrigation tubing and component(s), embodiments of the present
invention use the available (small diameter) space at the distal
end extremely efficiently. This efficient use of the space enables
that the electrodes of the distal end to be irrigated during
ablation, and enables force during ablation to be measured, without
requiring any increase in diameter of the catheter probe.
System Description
[0035] Reference is now made to FIG. 1, which is a schematic,
pictorial illustration of a catheter probe ablating system 10, and
to FIG. 2 which is a schematic cross-section of a distal end 12 of
a catheter probe 14 used in the system, according to embodiments of
the present invention. In system 10, catheter probe 14 comprises an
insertion tube 16, which is inserted into a lumen 18, such as a
chamber of a heart 20, of a subject 22. The catheter probe is used
by an operator 24 of system 10, during a procedure which typically
includes performing ablation of body tissue.
[0036] For intracardiac operation, insertion tube 16 and distal end
12 should generally have a very small outer diameter, typically of
the order of 2-3 mm. Therefore, all of the internal components of
catheter probe 14, are also made as small and thin as possible and
are arranged so as to, as much as possible, avoid damage due to
small mechanical strains.
[0037] The functioning of system 10 is managed by a system
controller 30, comprising a processing unit 32 communicating with a
memory 34, wherein is stored software for operation of system 10.
Controller 30 is typically an industry-standard personal computer
comprising a general-purpose computer processing unit. However, in
some embodiments, at least some of the functions of the controller
are performed using custom-designed hardware and software, such as
an application specific integrated circuit (ASIC) or a field
programmable gate array (FPGA). Controller 30 is typically managed
by operator 24 using a pointing device and a graphic user interface
(GUI) 38, which enable the operator to set parameters of system 10.
GUI 38 typically also displays results of the procedure to the
operator.
[0038] The software in memory 34 may be downloaded to the
controller in electronic form, over a network, for example.
Alternatively or additionally, the software may be provided on
non-transitory tangible media, such as optical, magnetic, or
electronic storage media.
[0039] One or more electrodes are mounted on distal end 12. By way
of example, FIG. 2 illustrates three such electrodes: a first
electrode 110, a second electrode 111, and a third electrode 112,
the electrodes being insulated from each other. The electrodes
typically comprise thin metal layers formed over an insulating
sheath 46 of tube 16. The distal end may have other electrodes,
insulated from each other and from electrodes 110, 111, and 112,
which for simplicity are not shown in the diagram. Electrode 110,
at the extremity of the distal end, by way of example is assumed to
have the shape of a cup with a flat base, and is herein also
referred to as the cup electrode. Cup electrode 110 typically has a
thickness in a range from approximately 0.1 mm to approximately 0.2
mm.
[0040] Second electrode 111 is in the form of a ring and is also
referred to herein as ring electrode 111. Ring electrode 111 is
typically formed from metal having a similar thickness as the cup
electrode. Third electrode 112 is an irrigated ring electrode. In
the present disclosure, electrodes 110, 111 and 112, and other
electrodes of the distal end, are also referred to herein
collectively as electrodes 115.
[0041] Electrodes 115 are connected to system controller 30 by
conductors in tube 16, not shown in the figures. As described
below, at least one of the electrodes is used to ablate tissue 26.
In addition to being used for ablation, the electrodes typically
perform other functions, as is known in the art; some of the other
functions are described below. As necessary, when used for other
functions, controller 30 may differentiate between the currents for
the different functions by frequency multiplexing. For example,
radio-frequency (RF) ablation power may be provided at frequencies
of the order of hundreds of kHz, while position sensing frequencies
may be at frequencies of the order of 1 kHz. A method of evaluating
the position of distal end 12 using impedances measured with
respect to the electrodes is disclosed in U.S. Patent Application
2010/0079158 to Bar-Tal et al., which is incorporated herein by
reference.
[0042] System controller 30 comprises a force module 48, an RF
ablation module 50, an irrigation module 52, and a tracking module
54. Processing unit 32 uses the force module to generate and
measure signals supplied to, and received from, a force sensor 58
in distal end 12 in order to measure the magnitude and direction of
the force on the distal end. The operation and construction of
force sensor 58 is described in more detail below.
[0043] Processing unit 32 uses the ablation module to monitor and
control ablation parameters such as the level of ablation power
applied via the one or more electrodes 115. The module also
monitors and controls the duration of the ablation that is
provided.
[0044] Typically, during ablation, heat is generated in the
electrode or electrodes providing the ablation, as well as in the
surrounding region. In order to dissipate the heat and to improve
the efficiency of the ablation process, system 10 supplies
irrigation fluid to distal end 12. System 10 uses irrigation module
52 to monitor and control irrigation parameters, such as the rate
of flow and the temperature of the irrigation fluid, as is
described in more detail below.
[0045] Unit 32 uses tracking module 54 to monitor the location and
orientation of the distal end relative to patient 22. The
monitoring may be implemented by any tracking method known in the
art, such as one provided in the Carto3.RTM. system produced by
Biosense Webster of Diamond Bar, Calif. Such a system uses
radio-frequency (RF) magnetic transmitter and receiver elements
external to patient 22 and within distal end 12. Alternatively or
additionally, the tracking may be implemented by measuring
impedances between one or more electrodes, and patch electrodes
attached to the skin of patient 22, such as is also provided in the
Carto3.RTM. system. For simplicity, elements specific to tracking
and that are used by module 54, such as the elements and patch
electrodes referred to above, are not shown in FIG. 1.
[0046] As shown in FIG. 2, distal end 12 is connected to insertion
tube 16. The distal end has mounted upon it electrodes 115, and
force sensor 58 is mounted within the distal end. Aspects of a
force sensor similar to force sensor 58 are described in U.S. Pat.
No. 8,357,152, to Govari et al., issued Jan. 22, 2013, and in U.S.
Patent Application 2011/0130648, to Beeckler et al., filed Nov. 30,
2009, both of whose disclosures are incorporated herein by
reference.
[0047] FIG. 2 shows a schematic, sectional view of force sensor 58.
Sensor 58 comprises a resilient coupling member 60, which forms a
spring joint 62 between two ends of the coupling member. By way of
example, coupling member 60 is assumed to be formed in two parts or
having two portions, a first part or portion 64 and a second part
or portion 66, the two parts being fixedly joined together. The two
parts of coupling member 60 are generally tubular, and are joined
so that the coupling member also has a tubular form with a central
opening. Although there is no necessity that coupling member 60 be
formed of two parts, the two-part implementation simplifies
assembly of elements comprised in the force sensor, as well as of
other elements mounted in the distal end, into the member.
[0048] Coupling member 60 typically has one or more helices 70 cut
in a portion of the length of first portion 64 of the member, so
that the member behaves as a spring. In an embodiment described
herein, and illustrated in FIG. 2, helices 70 are formed as two
intertwined helices, a first cut helix 72 and a second cut helix
74, which are also referred to herein as a double helix. However,
coupling member 60 may have any positive integral number of
helices, and those having ordinary skill in the art will be able to
adapt the present description without undue experimentation to
encompass numbers of helices other than two. Alternatively, the
coupling member may comprise a coil spring or any other suitable
sort of resilient component with similar flexibility and strength
characteristics to those generated by the one or more tubular
helical cuts, referred to above.
[0049] Coupling member 60 is mounted within and covered by sheath
46, which is typically formed from flexible plastic material.
Coupling member 60 typically has an outer diameter that is
approximately equal to the inner diameter of sheath 46. Such a
configuration, having the outer diameter of the coupling member to
be as large as possible, increases the sensitivity of force sensor
58. In addition, and as explained below, the relatively large
diameter of the tubular coupling member, and its relatively thin
walls, provide a central space 61 enclosed within the coupling
member which is occupied by other elements, described below, in the
distal end.
[0050] When catheter probe 14 is used, for example, in ablating
endocardial tissue by delivering RF electrical energy through
electrodes 115, considerable heat is generated in the area of
distal end 12. For this reason, it is desirable that sheath 46
comprises a heat-resistant plastic material, such as polyurethane,
whose shape and elasticity are not substantially affected by
exposure to the heat.
[0051] Within force sensor 58, typically within the central space
61 of the coupling member 60, a joint sensing assembly, comprising
coils 76, 78, 80 and 82, provides accurate reading of any
dimensional change in joint 62, including axial displacement and
angular deflection of the joint. These coils are one type of
magnetic transducer that may be used in embodiments of the present
invention. A "magnetic transducer," in the context of the present
patent application and in the claims, means a device that generates
a magnetic field in response to an applied electrical current
and/or outputs an electrical signal in response to an applied
magnetic field. Although the embodiments described herein use coils
as magnetic transducers, other types of magnetic transducers may be
used in alternative embodiments, as will be apparent to those
skilled in the art.
[0052] The coils in the sensing assembly are divided between two
subassemblies on opposite sides of joint 62: one subassembly
comprises coil 82, which is driven by a current, via a cable (not
shown) from controller 30 and force module 48, to generate a
magnetic field. This field is received by a second subassembly,
comprising coils 76, 78 and 80, which are located in a section of
the distal end that is spaced axially apart from coil 82. The term
"axial," as used in the context of the present patent application
and in the claims, refers to the direction of a longitudinal axis
of symmetry 84 of distal end 12. An axial plane is a plane
perpendicular to this longitudinal axis, and an axial section is a
portion of the catheter contained between two axial planes. Coil 82
typically has an axis of symmetry generally parallel to and
coincident with axis 84.
[0053] Coils 76, 78 and 80 are fixed in distal end 12 at different
radial locations. (The term "radial" refers to coordinates relative
to the axis 84.) Specifically, in this embodiment, coils 76, 78 and
80 are all located in the same axial plane at different azimuthal
angles about the catheter axis, and have respective axes of
symmetry generally parallel to axis 84. For example, the three
coils may be spaced azimuthally 120.degree. apart at the same
radial distance from the axis.
[0054] Coils 76, 78 and 80 generate electrical signals in response
to the magnetic field transmitted by coil 82. These signals are
conveyed by a cable (not shown) to controller 30, which uses force
module 48 to process the signals in order to measure the
displacement of joint 62 parallel to axis 84, as well as to measure
the angular deflection of the joint from the axis. From the
measured displacement and deflection, controller 30 is able to
evaluate, typically using a previously determined calibration table
stored in force module 48, a magnitude and a direction of the force
on joint 62.
[0055] Controller 30 uses tracking module 54 to measure the
location and orientation of distal end 12. The method of
measurement may be by any convenient process known in the art. In
one embodiment, magnetic fields generated external to patient 22
create electric signals in elements in the distal end, and
controller 30 uses the electric signal levels to evaluate the
distal end location and orientation. Alternatively, the magnetic
fields may be generated in the distal end, and the electrical
signals created by the fields may be measured external to patient
22. For simplicity, the elements in distal end 12 that are used to
track the distal end are not shown in FIG. 2. However, where such
elements comprise coils, at least some of coils 76, 78, 80, and 82
may be used as the tracking elements required in the distal end, in
addition to their use as elements of force sensor 58.
[0056] At least some of electrodes 115 are configured to have small
irrigation apertures. The apertures typically have diameters in an
approximate range 0.1-0.2 mm. In the embodiment described herein
cup electrode 110 and irrigated ring electrode 112 have respective
sets of irrigation apertures 86 and 90. The irrigation fluid for
the apertures is supplied by irrigation module 52, which uses
tubing 92 to transfer the fluid to the sets of irrigation
apertures.
[0057] The irrigation fluid is typically normal saline solution,
and the rate of flow of the fluid, controlled by module 52, is
typically in the range of approximately 10-20 cc/minute, but may be
higher or lower than this range.
[0058] Tubing 92 delivers fluid to the distal end of the catheter
probe. A distal end of the tubing 92 is received in a flow diverter
150 configured in the second (or proximal) portion 66 of the
coupling member 60. The fluid is routed to the electrodes by
passing through the diverter 150 which is advantageously situated
in and through the central space 61 of the coupling member 60 and
thus makes no extra demands on the dimensional requirements,
particularly the diameter, of the distal end, other than those
required for force sensor 58.
[0059] In this embodiment, flow diverter 150 may be positioned
within or near the axial plane of elliptical coils 142 and 144. For
example, flow diverter 150 and elliptical coils 142 and 144 may be
spaced radially about catheter axis 84 at different azimuthal
angles. This configuration allows flow diverter 150, and therefore,
irrigated ring electrode 112 to be positioned relatively distally
without interfering with the functionality of force sensor 58. It
may be desirable to reduce the distance between cup electrode 110
and ring electrode 112 to provide efficient ablation of the tissue
between the electrodes. At the same time, it may also be desirable
to position ring electrode 112 proximal to spring joint 122 so as
to reduce the distance between cup electrode 110 and force sensor
58, so that force sensor 58 may provide more accurate indication of
the position of cup electrode 110.
[0060] In some embodiments, the diverter 150 has an elongated body
between a distal end 151 and a proximal end 152, as shown in FIG. 3
and FIG. 4. An outer surface 160 of the diverter body has a
convexity with a curvature generally corresponding or matching the
outer curvature of the tubular form of the coupling member 60,
including the proximal portion 66. On the outer surface 160, a step
or indent formation 162 extends around a peripheral edge of the
outer surface. The body has tapered radial sides 166 and an inner
surface 164 with a concavity.
[0061] The diverter body has a fluid passage 153 that connects a
proximal entry opening 155, and a distal exit opening 156. The
fluid passage 153 includes a proximal axial branch distal of the
entry opening 155 and a distal radial branch proximal of the exit
opening 155. Thus, fluid entering the diverter through the entry
opening 155 is initially guided in an axial direction A, following
by a radial direction R before exiting the diverter through the
exit opening 156 in the outer surface 160. It is understood that
the fluid passage 153 may have any suitable cross-sectional shape,
including for example, circular, rectangular, or polygonal.
[0062] The diverter 150 is positioned in a sidewall 67 of the
proximal portion 66 of the coupling member 60. As shown in FIG. 5
and FIG. 6, a proximal end of the proximal portion 66 includes a
longitudinal slot 91 defined by an elongated U-shaped edge 95 with
a proximal opening that is coextensive with the proximal end 152 of
the diverter 150 when inserted in the slot 91. The diverter 150 is
inserted into the slot 91 by sliding engagement between the
peripheral indent formation 162 and the U-shaped edge 95. The
peripheral indent formation 162 has a rounded distal portion 170
that corresponds with the U-shaped edge 95. The outer surface 160
of the diverter 150 is generally flush or even with an outer
surface of sidewall of the proximal portion 66. The diverter 150
may be affixed in the slot 91 by adhesive applied between engaged
surfaces of the peripheral indent formation 162 and the U-shaped
edge 95, which also seals the engaged surfaces. The diverter 150 is
constructed of any suitable material, including, for example,
PEEK.
[0063] As shown in the embodiment of FIG. 3, FIG. 5 and FIG. 6, a
distal end of the tubing 92 is inserted and received in the entry
opening 155 at the proximal end 152 of the diverter 150. Where the
distal end includes a tubular component 165, for example, a guide
wire lumen, the inner surface 164 (with its concavity C) of the
diverter 150 generally conforms to a convex outer surface of the
tubular component 165. The tapered sides 166 minimize the demand on
space within the proximal portion 66. For example, the adjacent
tapered side does not physically interfere with elliptic coil 142.
As shown in FIG. 6, the diverter 150 leaves sufficient room within
the central space 61 to accommodate another elliptical coil 144,
and at least another tubing 145, for example, with a lumen 146 to
pass cables for receiving coils 76, 78 and 80, transmitting coil
82, and/or elliptic coils 142 and 144. Notably, lead wire 180 for
cup electrode 112 may be wound on an outer surface of the tubing
145, under a protective nonconductive sheath 182.
[0064] As shown in FIG. 5, the ring electrode 112 with apertures 90
is mounted over the proximal portion 66 of the coupling member 60,
in particular, over the exit opening 156. The sheath 46 is
positioned between the proximal portion 66 and the ring electrode
112 to prevent electrical shorting. The sheath has a through-hole
aligned with the exit opening 156.
[0065] In use, the diverter 150 receives fluid passed from the
tubing 92 into the entry opening 155 which travels through the
fluid passage 153 axially and then radially to exit from the exit
opening 156 of the diverter 150 and the through-hole 176 of the
sheath 46. The fluid then enters a sealed annular space gap G or
reservoir provided between the proximal portion 66 (and the sleeve
74), and a sidewall 114 of the ring electrode 112, before exiting
the ring electrode 112 via the apertures 90.
[0066] In other embodiments, a proximal portion 266 of a coupling
member has an integrated flow diverter 250, as shown in FIG. 7 and
FIG. 8. The diverter 250 is formed in a portion of a radial
projection or rib 262 extending inwardly into central space 261 of
the proximal portion 266. The radial projection 262 spans
longitudinally, along all or a portion of the length of the
proximal portion 266. Formed in a proximal portion of the radial
projection 262, a fluid passage 290 is defined by sidewalls,
including two radial sidewalls 280 and 281, an inner sidewall 282,
a distal end sidewall 283 which may be at a predetermined distance
from the distal end of the radial projection 262 or a distal end of
the proximal portion 266. These sidewalls and a sidewall portion
267 of the proximal portion 266 together define and surround the
fluid passage 290, which extends from a proximal entry opening 255
at proximal opening 263 to a distal exit opening 256 proximal to
the distal end of the proximal portion 266. The diverter 250 is
thus integral with the proximal portion 266. In that regard, the
proximal portion 266 and the integrated flow diverter 250 are
formed from a single body, of a common material, for example, a
superelastic alloy, such as nickel titanium (Nitinol).
[0067] The fluid passage 290 includes at least an axial branch 291
and radial branch 292, as shown in FIG. 8. An inner surface 284 of
the inner sidewall 282 has a concavity, as shown in FIG. 7, which
can conform to a tubular component within the central space 261 of
the portion 266
[0068] It is understood that the fluid passage 290 or 190 may
follow any suitable pattern, including combinations of one or more
axial or generally axial branches with one or more radial or
generally radial branches, between one or more entry openings and
one or more exit openings, with dedicated tubing supplying fluid to
each entry opening. For example, the fluid passage may include a Y
passage having a main axial branch and additional offset branches.
In FIG. 9, a diverter 450A of proximal portion 466A has an entry
opening 455, a proximal exit opening 456P, a distal exit opening
456D, a fluid passage an axial branch, a proximal radial branch,
and a distal radial branch. In FIG. 10, a diverter 450B of proximal
portion 466B has a proximal entry opening 455, a proximal exit
opening 456A, two distal exit openings 456B and 456C, a fluid
passage with an on-axis axial branch and two off-axis axial branch,
and three radial branches. In FIG. 11, diverter 450C of proximal
portion 466C has two separate and independent entry openings 455A
and 455B, each having a fluid passage with a respective axial
branch, radial branch and exit opening 456A and 456B.
[0069] For any of the foregoing embodiments, controller 30 of FIG.
1 may set the rate of flow to the individual electrodes according
to the function performed by the electrode. For example, if an
electrode is being used for ablation, controller 30 may increase
the flow rate through the electrode compared to when the electrode
is not being used for ablation. Alternatively or additionally,
controller 30 may alter the flow rate to a particular electrode
according to a value of a parameter measured by a sensor in the
distal end. Such parameters include the magnitude of the force
measured by force sensor 58, as well as the direction of the force
measured by the force sensor. Other sensors that the controller may
use to alter the flow rate include a temperature sensor in the
distal end.
[0070] Typically, controller 30 and irrigation module 52 maintain a
minimum rate of flow of irrigation fluid to each electrode, to
prevent blood entering the irrigation apertures of the electrodes.
In some embodiments, rather than having irrigation fluid supplied
to the separate electrodes via a common tubing, separate irrigation
tubes to each electrode are run from module 52 through catheter
probe 14. As shown in FIG. 2, distal cup electrode 110 is fed by
dedicated irrigation tube 126.
[0071] The preceding description has been presented with reference
to certain exemplary embodiments of the invention. Workers skilled
in the art and technology to which this invention pertains will
appreciate that alterations and changes to the described structure
may be practiced without meaningfully departing from the principal,
spirit and scope of this invention, and that the drawings are not
necessarily to scale. Moreover, it is understood that any one
feature of an embodiment may be used in lieu of or in addition to
feature(s) of other embodiments. Accordingly, the foregoing
description should not be read as pertaining only to the precise
structures described and illustrated in the accompanying drawings.
Rather, it should be read as consistent with and as support for the
following claims which are to have their fullest and fairest
scope.
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