U.S. patent application number 10/260242 was filed with the patent office on 2003-06-12 for electrophysiology/ablation catheter and remote actuator therefor.
This patent application is currently assigned to CARDIAC ASSIST DEVICES, INC.. Invention is credited to Rashidi, Rassoll.
Application Number | 20030109778 10/260242 |
Document ID | / |
Family ID | 26926409 |
Filed Date | 2003-06-12 |
United States Patent
Application |
20030109778 |
Kind Code |
A1 |
Rashidi, Rassoll |
June 12, 2003 |
Electrophysiology/ablation catheter and remote actuator
therefor
Abstract
A cardiac catheter employed for minimally invasive cardiac
diagnostic electrophysiology and/or cardiac ablation procedures.
The catheter of this invention comprises of an elongated
cylindrical and electrically non conductive main exterior tube with
plurality of surface electrodes disposed on its distal portion, and
a handle on its proximal end. The distal portion of this catheter
can be curved and the assumed curvature can be retained by a single
action on manual actuator of the catheter handle. In one embodiment
of this invention an electromechanical drive system is incorporated
into the catheter handle for formation of curvatures at the distal
portion of the catheter. In a further embodiment an electrical
heating element is incorporated within the distal electrode of the
catheter for ablation procedures. In another embodiment of this
invention a readily removable and disposable blood contacting
segment is provided. The non-blood contacting actuator is thus
reusable and reduces the cost of the cardiac electrophysiology
and/or ablation procedure. The catheter of this invention comprises
two tension/compression members for curvature formation at the
distal end of the catheter. These tension/compression or pull/push
members are wires with circular cross-sections that are integrally
formed into ribbon-like configurations at their distal portions for
enhanced deflectability. The actuator handle includes a pivoted
member movable in one direction by the thumb of the user's hand
grasping the handle and in the opposite direction by the other
fingers of the same hand.
Inventors: |
Rashidi, Rassoll;
(Cleveland, OH) |
Correspondence
Address: |
Timothy E. Nauman
FAY, SHARPE, FAGAN, MINNICH & McKEE, LLP
7th Floor
1100 Superior Avenue
Cleveland
OH
44114-2518
US
|
Assignee: |
CARDIAC ASSIST DEVICES,
INC.
|
Family ID: |
26926409 |
Appl. No.: |
10/260242 |
Filed: |
September 30, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10260242 |
Sep 30, 2002 |
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09232866 |
Jan 15, 1999 |
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09232866 |
Jan 15, 1999 |
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08880080 |
Jun 20, 1997 |
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5861024 |
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Current U.S.
Class: |
600/374 ;
606/41 |
Current CPC
Class: |
A61N 1/0565 20130101;
A61B 2018/00839 20130101; A61B 2017/003 20130101; A61B 18/1492
20130101 |
Class at
Publication: |
600/374 ;
606/41 |
International
Class: |
A61B 005/042; A61B
018/14 |
Claims
What is claimed:
1) An electrophysiology/ablation catheter comprising: a) an
elongated flexible hollow tubular casing having a proximal end and
distal end and a plurality of spaced electrodes disposed at the
distal end thereof, b) a pair of flexible tension/compression
members disposed in side by side relationship and extending in the
hollow of said casing from a point of attachment adjacent said
distal end to said proximal end of said tubular casing; c) an
electrical lead connected to each of said electrodes and extending
through the hollow of said tubular casing to the proximal end
thereof, said lead adapted for external connections thereto; d)
spacer means disposed between said pair of flexible
tension/compression members at said distal end for maintaining
lateral spacing between said members, said spacer means being
flexible; and, e wherein longitudinal tensioning of a first of said
tension/compression members and simultaneously longitudinal
compressing of the second of said tension/compression members with
respect to said casing effects lateral displacement of said distal
end of said casing in one direction and longitudinal tensioning of
the said second of tension/compression members and simultaneously
longitudinal compressing of the said first of said
tension/compression members with respect to said casing effects
lateral displacement of said distal end of said casing in a
direction opposite said one direction.
2) The catheter defined in claim 1, wherein said pair of
tension/compression members each have a portion thereof adjacent
said distal end formed to have a flattened transverse section.
3) The catheter defined in claim 1, wherein said spacer means
comprises a blade spring member.
4) The catheter defined in claim 1, wherein said spacer means
comprises a wave shaped spring member.
5) The catheter defined in claim 1, wherein each of said
tension/compression members has substantially rectangular
transverse section in the region adjacent said distal portion with
the balance thereof having a generally circular cross-section.
6) The catheter defined in claim 1, further comprising an elongated
flexible tubular guide member disposed in said casing, said guide
member having a pair of spaced parallel lumens formed therein with
one of said pair of tension/compression members disposed in each
lumen.
7) The catheter defined in claim 1, further comprising a sleeve
received over said flattened portion of said tension/compression
members and spaced a preselected distanced from said distal end,
said tension/compression members secured therein and forming a
kinematic junction at said sleeve, wherein the portion of said
tubular casing distal said sleeve remains substantially un-deformed
upon simultaneous tensioning and compressing of said
tension/compression members.
8) The catheter defined in claim 7, wherein said spacer means has
an end thereof secured in said sleeve with the other end of said
spacer floating in the space between said tension/compression
members.
9) The catheter defined in claim 1, further comprising an elongated
flexible tubular guide member disposed in said casing with said
tension/compression members received therethrough; and, a rigid
collar attached to the distal end of said guide member and
extending over a portion of said tension/compression members having
said spacer means therebetween.
10) The catheter defined in claim 9, wherein said rigid collar has
a flatted cross-section on one end and a generally circular
cross-section on an end opposite said one end.
11) The catheter defined in claim 1, further comprising an annular
reference electrode disposed on said tubular casing at a station
therealong remote from said plurality of spaced electrodes, wherein
said reference electrode is located such that it remains exterior
to the heart cavity upon insertion of the said plurality of spaced
electrodes into a heart cavity.
12) A method of making an electrophysiology/ablation catheter
comprising: a) disposing at least one electrode on a distal portion
of an elongated flexible tubular member and connecting an electrode
lead to said electrode and extending said electrode lead to a
proximal end of said tubular member; b) disposing a pair of
elongated tension/compression members in said tubular member and
fixing an end of each of said pair in the distal portion of said
tubular member and extending said pair to the proximal end of said
tubular member; c) disposing a flexible spacer intermediate said
tension/compression members in the region of the distal portion
thereof and spacing said tension/compression members laterally; d)
disposing an actuator movably on a handle and connecting said
handle to the proximal end of said tubular member; and, e)
connecting said actuator to the proximal ends of said
tension/compression members.
13) The method defined in claim 12, wherein said of fixing includes
securing by weldment.
14) The method defined in claim 12, wherein said step of disposing
a flexible spacer includes securing an end of said spacer to said
tension/compression members by weldment.
15) The method defined in claim 12, wherein said step of disposing
a flexible spacer includes flattening a portion of the distal end
of said tension/compression members and securing an end of said
spacer thereto by weldment.
16) The method defined in claim 12, further comprising disposing a
sleeve over said tension/compression members and positioning said
sleeve a preselected distance from said distal end and securing
said sleeve to said tension/compression members and forming a
kinematic junction thereof at said sleeve
17) The method defined in claim 12, wherein said fixing includes
disposing an additional flexible tube within said casing a certain
distance from said distal end and partially stiffening a portion of
said tubular member.
18) A method of installing a distal electrode to an
electrophysiology/ablation catheter comprising: a) providing a
generally cup-shaped member of electrically conductive material and
forming a plurality of spaced fingers extending axially from the
rim of said cup-shaped member; b) disposing the open end of said
cup-shaped member over an end of a tubular catheter casing member
and deforming said fingers radially inwardly and passing at least
one said fingers through the wall of said tubular member and
securing said cup-shaped member to said tubular member with said
finger; and, c) attaching an electrical lead to said at least one
finger and extending said lead through said tubular member.
19) The method defined in claim 18, wherein said step of securing
includes further deforming said fingers and extending said at least
one finger along the inner surface of said tubular member.
20) The method defined in claim 18, wherein each step of securing
includes further deforming said at least one finger to fold back on
itself along the inner surface of the said tubular member.
21) The method defined in claim 18, wherein said step of passing
said at least one finger through said tubular member includes
piercing said wall with said at least one finger.
22) A motorized electrophysiology/ablation catheter actuating
assembly comprising: a) an elongated flexible tubular member having
a distal end and a proximal end and having a pair of
tension/compression members disposed therein and kinematically
joined in said distal end, said tension/compression members
extending through the proximal end of said tubular member; b)
hollow handle structure attached to the proximal end of said
tubular member, said handle structure having therein a motor drive
including means for connecting motor rotation to linear movement
with the proximal ends of said tension/compression members
connected to said means for connecting, c) a source of electrical
power disposed in said handle structure and user operated switch
means disposed on said handle structure for energizing said motor
drive, wherein said motor drive is operative, upon being energized
for rotation in one direction, to cause said means for converting
rotation to simultaneously pull and push said first and second
tension/compression members respectively and effect curvature of
said tubular member in one direction; and said motor drive is
operative, upon being energized for rotation in a direction
opposite said one direction to cause said means for converting
rotation to simultaneously pull and push said second and first
tension/compression members respectively and effect curvature of
said tubular member in the opposite direction.
23) The assembly defined in claim 22, wherein said handle structure
includes a position sensor for sensing the position of a member of
said means for converting motor rotation to linear motion as an
indication of the radius of curvature of the distal portion of said
tubular member.
24) The assembly defined in claim 22, wherein said handle structure
includes connector means adapted for external electrical
connection; and, said tubular member includes lead means connected
to at least one distal electrode, said lead means having the
proximal end thereof connected to said connector means.
25) The assembly defined in claim 22, wherein said connector means
includes connections for remote control of said motor drive.
26) The catheter defined in claim 1 further comprising a solid
state temperature sensor disposed in said distal electrode and
sensing lead means connected to said sensor, said sensing leads
means extending through said casing to the proximal end thereof for
connection to a sensing circuit.
27) The catheter defined in claim 1 further comprising a fiber
optic temperature sensor received through said casing, having an
end thereof connected to said distal electrode for conducting a
temperature sensing signals to the proximal end thereof.
28) The catheter defined in claim 1 further comprising: a) heating
element disposed in said distal electrode; b) electrical supply
lead means connected to said distal electrode, said supply lead
means extending through said casing to the proximal end thereof
wherein upon powering said lead means, said distal electrode is
heated. c) electric power supply and temperature control module
disposed in said handle to control the temperature of said distal
electrode for ablation procedures.
29) The catheter defined in claim 28 further comprising a solid
state temperature sensor disposed in said distal electrode and
sensing lead means connected to said sensor, said sensing leads
means extending through said casing to the proximal end thereof for
connection to a sensing circuit disposed in said handle.
30) The catheter defined in claim 1, wherein said distal portion of
said tension/compression members are received in a flexible guide
tube disposed within said casing, said guide tube having an end
engaging said distal electrode.
31) The catheter defined in claim 28, wherein said flexible guide
tube has a pair of internal septum formed therein extending the
length thereof for separating said tension/compression members and
said spacer means
32) The catheter defined in claim 1, wherein the proximal end of
each of said tension/compression members is received in a closely
fitting metal tube; and, said metal tube is deformed by clamping
and said tube and tension/compression member are secured to a
reciprocating member operationally connected to said actuator
member.
33) The catheter defined in claim 1, wherein said handle includes a
pair of reciprocating members operationally connected to said
actuator member, with each reciprocating member connected to one of
said tension/compression members; and, said handle includes a
displacement sensor operative to sense the motion of at least one
of said reciprocating members.
34) The catheter defined in claim 1, wherein said handle includes
means operable for frictionally securing said actuator in a user
selected position.
35) The catheter of claim 34, wherein said means for frictionally
securing includes an elastic rubber.
36) The catheter defined in claim 32, wherein said means for
frictionally securing includes a spring loaded plunger.
37) The catheter defined in claim 1 further comprising an elastic
collar received over the proximal end of said casing, said collar
operable to grip said casing upon user grasping thereof for
enabling the user to readily apply torque to said casing.
38) The catheter defined in claim 37, wherein said collar is
axially moveable along said casing for permitting user selection of
the region of torque application therealong.
39) A method of installing an annular electrode on a flexible
catheter casing comprising: a) attaching an end of an electrical
lead to said electrode; b) forming an aperture in said casing and
passing the remote end of said lead through said aperture; c)
securing the proximal end of the casing over a rigid tube; d)
stretching said casing axially, necking said casing and sliding
said electrode over said casing and positioning said electrode over
said aperture with said lead therethrough; e) releasing said
stretching to expand said necking and securing said electrode on
said casing; and, f) removing excess casing material.
40) The catheter defined in claim 1, wherein said distal electrode
and said plurality of spaced annular electrodes are made from
electrically conductive rubber-like material.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Continuation-In-Part of my co-pending
application Ser. No. 08/880,080 filed Jun. 20, 1997
entitled:"Electrophysiology Catheter and Remote Actuator
Therefor."
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
MICROFICHE APPENDIX
[0003] Not Applicable
BACKGROUND OF THE INVENTION
[0004] a) Field of the Invention
[0005] The present invention relates to a catheter employed for
diagnostic and/or therapeutic procedures in medicine, more
specifically in minimally invasive cardiac electrophysiology
studies and/or cardiac ablation procedures.
[0006] b) Description of the Prior Art
[0007] The primary device for an intra-cardiac electrophysiology
study is a catheter with conductive electrodes at its distal
portion [U.S. Pat. Nos. 5,156,151, 5,279,299, 5,415,633, 5,454,370,
5,465,717]. The distal portion of the catheter, where the
electrodes are located, is commonly placed transvenously into the
heart to monitor and/or record the intra-cardiac electrical signals
during electrophysiology studies, or during intra-cardiac mapping.
The function of these electrodes on the catheter is to conduct
cardiac electrical signals to appropriate monitoring and recording
devices.
[0008] During the diagnostic procedures, the catheter is also used
as a medium to deliver low energy electrical pulses from a cardiac
stimulator to the heart in order to evaluate the heart's response
to the cardiac stimulator signals.
[0009] During therapeutic (cardiac ablation) procedures, electrical
energy in the form of radio-frequency, microwave or high-voltage
pulses is delivered from an appropriate energy source to the heart
commonly via the catheter's distal electrode. The intent of this
energy delivery is to destroy the site of the cardiac tissue that
causes abnormality (arrhythmia) to the normal rhythm of the
heart.
[0010] During such a minimally invasive cardiac ablation procedure
the distal portion of a catheter, which usually comprises a
plurality of spaced annular cylindrical electrodes and a distal
electrode, is transvenously placed into the heart. The proximal end
of the catheter, remote from the electrodes, has electrical leads
which are connected to an appropriate recording and/or monitoring
device. The intra-cardiac electrical signals can then be monitored
and recorded.
[0011] A surface electrocardiogram, obtained from patient's skin,
is concurrently compared with the intra-cardiac electrical signals.
Typically, when a known catheter is employed for ablation
procedures, an electrically conductive self adhesive skin patch is
also placed on the patient's body. An electrical lead from this
patch is connected to an electrical energy source. As the abnormal
site of the cardiac tissue is detected with the catheter's distal
electrode, its corresponding electrical lead is switched from the
monitoring/recording device to the electrical energy source for
ablation. At this time, electrical energy can be delivered to the
heart from the catheter tip that is in contact with abnormal heart
tissue. The self adhesive patch on the patient's body is the return
path of the electrical energy to the energy source. This known
ablation procedure, using a self-adhesive patch as the return path
of electrical energy to the energy source, may result in a
significant level of electrical "noise" that is generated by the
energy source during the energy delivery period. This "noise"
superimposes itself to both surface electrocardiograms and
intra-cardiac signals obtained from the catheter. Cardiac signals
contaminated with such "noise" have been found difficult to monitor
during energy delivery period.
[0012] Intra-cardiac signals are commonly acquired for
electrophysiology studies via a selected pair of a catheter's
electrodes. The catheter is said to be used as a bi-polar probe
when a cardiac signal is obtained between any pair of its
electrodes. In some electrophysiology studies or cardiac mapping,
however, the catheter is used as a uni-polar probe. When catheters
of the prior art have been employed as a uni-polar probe, an
additional reference electrode, that is not a part of the inserted
catheter, is needed to complete the electrical circuit path. In
such an arrangement, a second catheter is transveneously placed
into the heart and this second catheter electrode functions as the
reference electrode. U.S. Pat. No. 4,920,980 describes uni-polar
and bio-polar application of cardiac catheters.
[0013] Currently most widely used and commercially available
cardiac diagnostic and ablation catheters are sold for
"one-time-use-only", and the entire catheter is discarded after a
single use. Catheters of this type are relatively expensive. The
catheter price and the convention of its "one-time-use-only" have
an impact on the overall cost of cardiac electrophysiology and
ablation procedures.
[0014] Typically, known catheters have a generally cylindrical
electrically non-conductive body which has a plurality of spaced
annular surface electrodes on the distal end with a
hemispherically-shaped tip electrode. Each electrode has a
relatively fine electrically conductive wire attached thereto and
embedded in the catheter's main body (tube) and extending from the
distal end to the proximal end (catheter handle) where the
electrical connectors such as plugs or jacks are provided to be
plugged into a corresponding sockets provided in recording and
monitoring devices.
[0015] Typically, the main body of these catheters comprises a
flexible tube constructed from polyurethane, nylon or some other
electrically non-conductive flexible material with braided steel
wires or other non metallic fibers in its wall as re-enforcing
elements. An early example of such construction is that shown and
described in U.S. Pat. No. 3,416,531 issued to M. L. Edwards.
Catheters of this type are available in two general categories: a)
those having a non-deflectable distal portion, an example of which
is shown and described in U.S. Pat. No. 3,190,286 issued to R. W.
Stokes, and b) those having a deflectable distal portion, as for
example the catheter shown and described in U.S. Pat. No. 3,605,725
issued to I. E. Bentov. The distal portion of deflectable type
catheters is typically made from non-braided flexible tube. This
portion can be deformed into a variety of curved configurations
with different radii of curvature by means of user input to a
manual actuator on the catheter handle. The actuator is commonly
internally linked to the catheter distal portion or the tip
electrode by at least one steel tension or pull wire.
[0016] The proximal end of the tension or pull wire(s) is connected
to a tensioning or puller mechanism in the handle. The distal end
of the tension or pull wire(s) is fixed to the catheter distal
electrode or anchored to a point on the catheter distal
portion.
[0017] Catheters of this type also commonly comprise a flexible
guide tube within the main body (tube) for bearing, in longitudinal
or axial direction, the thrust or compression reaction of the
flexible pull wire(s). An example of this latter type of
configuration is shown and described in U.S. Pat. No. 3,906,938
issued to J. J. Fleischhacher and U.S. Pat. No. 3,521,620 issued to
W. A. Cook. In the catheters of the prior art, such as those
described in the aforesaid Cook and Fleischhacher patents, the
inner flexible guide tube is formed by winding a tight coil of
spring wire with the adjacent turns in contacting or closed
relationship so that the inner guide tube will not compress
longitudinally, but is freely flexible in bending. The tension
wire(s) slides freely through this guide or coil spring type inner
tube. The proximal end of the inner guide tube, in the aforesaid
type catheters, is fixed to the catheter handle. The distal end of
the inner guide tube is disposed in the distal portion of the
catheter tubular main body. In one known catheter construction, one
end of a bendable compression strut is seated on the distal end of
the inner guide tube; and, the distal end of the pull wire(s) is
fixed to the distal end of a bendable strut. Catheters employing
such a strut are shown and described in the aforementioned Cook and
Fleischhacher patents. See also U.S. Pat. No. 5,108,368 issued to
Hammerslag for a catheter with a strut. In such known catheters, as
tension is applied to the pull wire by the manual actuator on the
catheter handle, the catheter distal portion assumes a curved
configuration.
[0018] One of the distinctive parts of deflectable distal portion
catheters is the pull wire mechanism that is commonly located in
the proximal end (handle) of the catheter. This mechanism usually
includes a manual actuator by which the catheter distal portion can
be deflected. The primary difference among the designs of
deflectable distal portion catheters is in the catheter handle,
more specifically, the tension or pull wire mechanism. This
mechanism transmits the manual force applied to the actuator on the
handle to the catheter distal portion via the pull wire(s), for
formation of a desirable radius of curvature at the distal portion
of the catheter. A catheter employing a partially rotating "wheel"
or "cam" mechanism for pull wire(s) is disclosed in U.S. Pat. No.
5,273,535 issued to S. D. Edwards et al. A rectilinearly moving
arrangement for the pull wire is disclosed in U.S. Pat. No.
4,960,134 issued to W. W. Webster, Jr. A shapeable or bendable
catheter handle for curvature formation on the distal portion of
the catheter is disclosed in U.S. Pat. No. 5,318,525 issued to
Scott West et al. A rotating collar or thumb-wheel type actuator is
disclosed in U.S. Pat. No. 3,416,531, issued to M. L. Edwards.
[0019] The primary desirable performance features of the
deflectable distal portion catheters are:
[0020] Ease of operation: ergonomic design to provide for the best
use of physician's hand anatomy for catheter handling and
usage;
[0021] A relatively low force requirement on the manual actuator of
the catheter handle for formation of curvature at the catheter
distal portion;
[0022] A comfortable range of displacement of the manual actuator
to provide for a full range of curvature formation at the distal
portion of the catheter; and,
[0023] A simultaneous curvature formation and curvature retention
at the distal portion of the catheter by a single action of the
physician's finger(s).
[0024] The above desirable performance features for the catheters
with deflectable distal portion have not been met by known
commercially available catheters. The catheters of the prior art
referenced in this document have not satisfied all of the desirable
performance features mentioned above. For example, in the aforesaid
U.S. Pat. No. 4,960,134, issued to Webster Jr., the sliding pull
wire arrangement does not satisfy the low force requirement on the
manual actuator of the catheter handle for formation of curvature
at the catheter distal portion.
[0025] In the aforesaid U.S. Pat. No. 5,273,535, issued to Edward
et al, a catheter is disclosed with two manual actuators on the
catheter handle; one actuator is employed for formation of
curvature at the distal portion of the catheter; and, the other
actuator is used for retention of curvature or locking. This
catheter requires two independent manual actions on both actuators
in order to form and retain a desirable radius of curvature on the
distal portion of the catheter. Therefore, the Catheter of U.S.
Pat. No. 5,273,535 (Edwards et al) fails to satisfy a simultaneous
curvature formation and curvature retention at the distal portion
of the catheter by a single action of the operators hand.
[0026] Attempts have been made in the prior art catheters to
provide a relatively laterally flexible distal portion for ease of
its navigation through the vascular branches of the heart. In U.S.
Pat. No. 5,203,772, issued to Gary R. Hammerslag et al, a steerable
tip guide wire is disclosed for percutaneous transluminal insertion
into the coronary vascular branches. The structure of the guide
wire of the '772 Hammerslag et al, catheter comprises a spring coil
wherein adjacent loops of the spring coil are "closed" or normally
in contact with each other, except the loops that form the
deflectable distal portion of the guide wire. The closed or
contacting loops and the open or non-contacting loops of the guide
wire of the '772 Hamemerslag et al construction provide an axially
relatively non-compressible structure in the region of the stacked
loops, with a relatively laterally flexible distal portion formed
in the region of the open loops.
[0027] U.S. Pat. No. 3,521,620 issued to William Cook discloses a
similar guide wire structure having contacting and non-contacting
portions with a deflectable tip for the same intended use as the
aforementioned Hammerslag '772 guide wire.
[0028] The cardiac catheters of the prior art are not only
expensive but are solely for "one-time-use-only". The catheter
price and the convention of "one-time-use-only" increases the
overall cost of electrophysiology and ablation procedures.
[0029] Presently employed known methods of cardiac ablation
procedure and presently employed known ablation catheters have the
disadvantage of requiring an electrically conductive patch on the
patient skin during the procedure. The function of this patch is to
return the delivered electrical charge, from the catheter electrode
inside the heart, to the ablation energy source.
BRIEF SUMMARY OF THE INVENTION
[0030] It is an objective of the present invention to provide an
electrophysiology catheter with a deflectable distal portion having
the following features:
[0031] An ergonomically comfortable range of motion of the manual
actuator for a full range of curvature formation at the distal
portion of the catheter;
[0032] A low manual force requirement, applied by a single hand of
the user, on the handle actuator for formation of curvature at the
distal portion of the catheter;
[0033] A simultaneous curvature formation and curvature retention
capability at the distal portion of the catheter by a single action
of the operator's hand;
[0034] It is another objective of this invention to provide a
catheter with a manual actuator on the catheter handle that is
operated with the joint actions of index finger and the thumb in
order to make the most efficient use of the anatomy of the
operator's hand.
[0035] A further objective of this invention is to provide an
electrophysiology and/or ablation catheter incorporating a sensor
in the catheter handle to detect the longitudinal displacement of
the pull/push wires and which can be correlated to the radius of
curvature at the distal portion of the catheter for monitoring
purposes.
[0036] Another objective of this invention is to provide an
electromechanical drive system in the catheter handle to substitute
the manual effort for formation of curvature at the distal portion
of the catheter. The electromechanical drive system can also be
controlled and manipulated via tele-communicated commands. The
electromechanical system can also be over-ridden manually in the
event of the failure of the drive unit.
[0037] A further objective of this invention is to provide an
electrophysiology catheter having a disposable blood contacting
portion comprising the catheter main body and electrodes with a
deflectable distal segment. A re-useable portion comprising the
actuator handle with its associated tip deflecting mechanism which
is easily attachable/detachable from the blood contacting
portion.
[0038] Another objective of the present invention is to provide an
electrophysiology catheter incorporating an extra electrode on the
catheter's exterior tube that can be employed as a reference
electrode if desired for a uni-polar application of the
catheter.
[0039] A further objective of this invention is to provide an
electrophysiology catheter having a deflectable distal portion with
a self contained heating element within its distal electrode that
can be employed for ablation procedures
[0040] Another objective of this invention is to provide a
stand-alone electrophysiology catheter having deflectable distal
portion with a self contained heating element within its distal
electrode and a self contained power supply in its proximal handle
portion that can be employed for cardiac mapping and cardiac
ablation procedures.
[0041] A further objective of this invention is to provide an
electrophysiology and/or ablation catheter with deflectable distal
portion that can easily be manufactured in smallest possible size
that can offer desirable bending characteristics at the catheter
distal portion.
[0042] A further objective of this invention is to provide an
electrophysiology catheter having independent pull/push wire length
adjuster units for each pull/push wire in the catheter handle for
independent removal of slack from each individual pull/push
wire.
[0043] This invention provides a catheter employed for cardiac
electrophysiology studies and/or cardiac ablation procedure. The
catheter of this invention comprises of two main sub-structures.
The first sub-structure is the blood contacting segment that
includes: a) the catheter elongated tubular body, and b) the
electrodes. The second sub-structure is the mechanism for formation
of curvatures at the distal portion of the catheter. This mechanism
includes: the catheter handle and its associated components.
[0044] The catheter presented in this invention offers the
following desirable features:
[0045] A simultaneous curvature formation and curvature retention
at the distal portion of the catheter by a single action of one
hand of the user.
[0046] An ergonomic handle for curvature formation at the distal
portion of the catheter that makes the most comfortable and
efficient use of the user's hand anatomy.
[0047] A sensing unit within the catheter handle to be employed for
displaying the radius of curvature at the catheter distal
portion.
[0048] In one embodiment of the present invention the blood
contacting portion is disposable, i.e. used only once, thereby
maintaining all safety and effectiveness requirements, yet the
overall catheter use cost is significantly reduced by allowing
re-use of the non-blood contacting portions.
[0049] In one embodiment of this invention an ablation catheter
with a self-heating element at its distal electrode is disclosed.
Ablation with this catheter eliminates the need for a self-adhesive
patch on the patient's body.
[0050] In one embodiment of the present invention an additional
electrode, that can be employed as a reference electrode, is
incorporated in the catheter for enabling uni-polar application of
the catheter, thereby eliminating the need for the placement of a
second catheter in the patient's heart.
[0051] The present invention offers the following additional
attribute:
[0052] An electromechanical battery operated drive system in the
catheter handle as an alternative for the manual drive components
of the distal portion curvature formation mechanism.
[0053] The present invention utilizes a novel catheter construction
which eliminates the compression loading of the inner guide tube
and provides design flexibility and economies in construction.
BRIEF DESCRIPTION OF THE DRAWINGS
[0054] FIG. 1 is a perspective view of the cardiac catheter
presented in this invention;
[0055] FIG. 2a is a overall view of the non-blood contacting
segments of the catheter of FIG. 1;
[0056] FIG. 2b is an enlarged view of the encircled distal portion
of the non-blood contacting segment of the catheter of FIG. 1;
[0057] FIG. 3a is an enlarged cross-section through the axis of
inner guide tube of the catheter of FIG. 1;
[0058] FIG. 3b is a left end view of FIG. 3a;
[0059] FIG. 4 Shows a top sectional view of the slider-crank
pull/push wire mechanism of the catheter handle of FIG. 1;
[0060] FIG. 5 Shows an exploded view of the slider-crank pull/push
wire mechanism of the catheter of FIG. 1;
[0061] FIG. 6a is a plan view of the delta-shaped actuator of the
catheter of FIG. 1;
[0062] FIG. 6b is a section view taken along section-indicating
line 6b-6b of FIG. 6a;
[0063] FIG. 6c is a right end view of FIG. 6a;
[0064] FIG. 7a Shows an enlarged view of the slider block and the
length adjuster of
[0065] the pull/push wire mechanism of the catheter of FIG. 1;
[0066] FIG. 7b is a section view taken along section-indicating
lines 7b-7b of FIG. 7a;
[0067] FIG. 7c is a section view taken along section-indicating
lines 7c-7c of FIG. 7a;
[0068] FIG. 7d is a section view taken along section-indicating
lines 7d-7d of FIG. 7a;
[0069] FIG. 8 Shows a plan sectional view of the catheter handle
with the actuator partially rotated counterclockwise, thereby
pulling one tension/compression member and pushing the other
tension/compression member;
[0070] FIG. 9 Shows a plan sectional view of an alternative
embodiment for the catheter handle with a cam-follower
mechanism;
[0071] FIG. 10 Shows an enlarged view of the cam-follower mechanism
of FIG. 9;
[0072] FIG. 11 Shows a plan sectional view of the catheter handle
with the cam-follower mechanism and the actuator partially rotated
counterclockwise, thereby pulling one tension/compression member
and pushing the other tension/compression member;
[0073] FIG. 12 Shows a plan sectional view of the cam-follower
mechanism with a circular disc actuator;
[0074] FIG. 13 Shows the cam-follower mechanism with a circular
disc actuator partially rotated counterclockwise, thereby pulling
one tension/compression member and pushing the other
tension/compression member;
[0075] FIG. 14 Shows a plan sectional view of a further embodiment
of a rack-pinion mechanism of the catheter handle;
[0076] FIG. 15 Shows a plan sectional view of the catheter handle
with the rack-pinion mechanism and the actuator partially rotated
counterclockwise, thereby pulling one tension/compression member
and pushing the other tension/compression member;
[0077] FIG. 16a Shows a plan sectional view of the catheter handle
with rack-pinion mechanism having a circular disc actuator;
[0078] FIG. 16b is a view similar to FIG. 16a showing the disk
actuator rotated in a counterclockwise direction from the position
of FIG. 16a;
[0079] FIG. 17 Shows a perspective view of yet another embodiment
of the catheter handle with an electromechanical drive system and
associated control components in two main segments 60 and 61;
[0080] FIG. 18 Shows a perspective view of catheter handle of FIG.
17 with the two main segments attached together;
[0081] FIG. 19 Shows a sectional view of the ablation catheter with
a heating element within its distal electrode;
[0082] FIG. 20a Shows the blood contacting segment of the partially
disposable catheter with a quick attachment/detachment plug;
[0083] FIG. 20b is a view of the non-blood contacting segments of
the catheter with a quick attachment/detachment jack;
[0084] FIG. 20c Shows the process of attachment/detachment of the
blood contacting and
[0085] non-blood contacting segments of the partially disposable
catheter;
[0086] FIG. 20d Shows the segments of FIG. 20c fully assembled;
[0087] FIG. 21 is an enlarged view of the electrical connector of
handle 182 of FIGS. 20b and 20c;
[0088] FIG. 22 is an enlarged view of the electrical connector of
the disposable blood contacting portion 166 of FIGS. 20a, 20c, and
20d;
[0089] FIG. 23 is an enlarged view of the assembly of the
connectors of FIGS. 21 and 22;
[0090] FIG. 24 Shows a perspective view of a cup-shaped distal
electrode;
[0091] FIG. 25 Shows a sectional view of the distal portion of the
catheter main body and its connection to the cup-shaped distal
electrode;
[0092] FIG. 26 is an exploded view of another embodiment of the
catheter handle with a Scotch-Yoke mechanism for moving the
tension/compression members;
[0093] FIG. 27 is a section view of the assembled mechanism of FIG.
26;
[0094] FIG. 28 is a cross-section similar to FIG. 2b of an
alternate embodiment of the non-blood contacting inner guide tube
and its associated components;
[0095] FIG. 29 is a view showing the embodiment of FIG. 28 in the
deflected condition; and,
[0096] FIG. 30 is a view showing the actuator handle assembly as
grasped by the user's hand.
[0097] FIG. 31 is a longitudinal cross-section of the distal
portion of another embodiment of the electrophysiology/ablation
catheter of the present invention;
[0098] FIG. 32 is an enlarged view of a portion of FIG. 31;
[0099] FIG. 33 is a longitudinal section view similar to FIG. 31 of
an alternate embodiment of the invention of FIG. 31;
[0100] FIG. 34 is a section view taken along section indicating
lines 34-34 of FIG. 33;
[0101] FIG. 35 is a section view taken along section indicating
lines 35-35 of FIG. 33;
[0102] FIG. 36 is a section view taken along section indicating
lines 36-36 of FIG. 33;
[0103] FIG. 37 is a section view taken along section indicating
lines 37-37 of FIG. 33;
[0104] FIG. 38 is a longitudinal section view of the catheter of
FIG. 33 in a modified embodiment with the distal portion thereof
undeformed during curvature;
[0105] FIG. 39 is an enlarged view of the distal guide tube of the
embodiment of FIGS. 33 and 38;
[0106] FIG. 40 is a longitudinal section of an ablation catheter
embodying the present invention and having a self contained power
source and temperature control in the handle;
[0107] FIG. 41 is an enlarged detail section view of the distal end
of the ablation catheter of FIG. 40;
[0108] FIG. 42 is a view similar to FIG. 40 showing an alternate
embodiment of the distal end of te ablation catheter of FIG.
40;
[0109] FIG. 43 is a longitudinal section view of an alternate
embodiment of the ablation catheter of FIG. 40;
[0110] FIG. 44 is an enlarged section view of the proximal end of
te catheter of the present invention illustrating the attachment of
the tension/compression members to the sliders;
[0111] FIG. 45 is a longitudinal section view of an embodiment of
the invention employing a self positioning friction brake for the
actuator of te handle;
[0112] FIG. 46 is a view similar to FIG. 45 showing the actuator in
a position for causing curvature at the distal portion of the
catheter;
[0113] FIG. 47 is a schematic view of the sliders of the handle of
he present invention showing a displacement transducer;
[0114] FIG. 48 is a perspective view of the catheter of the present
invention employing a collar thereon for enabling user to apply
torque to the braided outer casing tube of te catheter;
[0115] FIG. 49 is a view of the components prior to commencing
assembly of the annular electrodes at the distal portion of the
catheter;
[0116] FIG. 50 is a view of the first step of assembly of the
annular electrodes;
[0117] FIG. 51 is a view of te step subsequent to the step of FIG.
50;
[0118] FIG. 52 indicates a further step from the assembly of FIG.
51;
[0119] FIG. 53 indicates a subsequent step from FIG. 52;
[0120] FIG. 54 indicates the final step in assembling annular
electrodes onto the catheter casing;
[0121] FIG. 55 is a schematic for the temperature control of the
ablation catheter of FIG. 40;
[0122] FIG. 56 is a longitudinal section view of the positioning
brake for the actuator of the handle of the catheter;
[0123] FIG. 57 is an enlarged view of a portion of FIG. 56;
[0124] FIG. 58 is an exploded view of the embodiment of FIG. 33
DETAILED DESCRIPTION OF THE INVENTION
[0125] Referring now to the drawings, which are not intended to
limit the invention, FIG. 1 illustrates a perspective view of one
embodiment of the catheter assembly including the elongated
flexible main body indicated generally at 1. The catheter of this
invention is comprised of two main components: i) a blood
contacting segment that includes the catheter elongated exterior
tubular body 2 with a plurality of spaced electrodes 3 and a distal
electrode 5; and ii) a sub-assembly comprising the actuator
mechanism for affecting the catheter distal curvature which
includes a catheter handle and its associated components which is
indicated generally at 4. The blood contacting segment 2 comprises
of an elongated cylindrical electrically non-conducting preferably
braided main exterior tube 2 with a plurality of spaced annular
surface electrodes 3 on its distal portion and a hemispherically
shaped solid or hollow cup-shaped distal electrode 5. The distal
portion of the catheter denoted by the reference character "L" is a
non-braided tube that is significantly more flexible or softer than
the rest of main exterior tube 2. Each of the electrodes 3,5 has a
fine electrical conductor wire 6 attached thereto, which extends
within the length of the catheter and through handle 4 and
outwardly to a corresponding one of the plugs/jacks 8 disposed at
the proximal end of the catheter handle sub-assembly 4.
[0126] FIG. 2a shows the catheter assembly 1 of the present
invention with the tubular body 2 removed, thereby exposing the
non-blood contacting segment of the catheter generally denoted by
reference numeral 9.
[0127] When the first sub-structure 2 is assembled over the inner
guide tube 9 of the catheter handle 4, the distal portion 10 of the
inner guide tube 9 is situated or disposed in the distal
non-braided portion of the catheter exterior tube 2. The catheter
distal portion L of FIG. 1 assumes the same curved configurations
as that of the distal portion 10 of the inner guide tube 9 in
response to the user manipulations of the actuator 18 on the
catheter handle 4.
[0128] Referring to FIGS. 2a and 2b the non-blood contacting
segment of the catheter of this invention includes:
[0129] an inner guide tube indicated generally at 9,
[0130] a pair of tension/compression members 11,12 comprising
flattened portions 11' and 12',
[0131] a catheter handle 4,
[0132] and a plurality of electrical plugs 8
[0133] Referring to FIG. 2b, the entire length of the inner guide
tube 9 and its distal portion along the length 10 is disposed
within the tubular body 2 of FIG. 1. FIGS. 3a and 3b show the area
of FIG. 2b in further enlargement wherein the inner guide tube 9 is
a flexible body made from spring wire in the region denoted by
reference numeral 14; and, is preferably formed as a tightly wound
spring with adjacent coils contacting or closed windings. The inner
guide tube 9 has disposed therein at least two tension/compression
members in the form of wires 11 and 12. The tension/compression
members 11, 12 have a generally circular cross-section and extend
preferably along the length of the elongated inner guide tube 9 and
have a generally flattened ribbon-like configuration 11', 12' in
the region 10 of guide tube 9. The inner guide tube 9 is formed to
have generally circular cross-section. The windings of the distal
portion 10 of the inner guide tube 9 are permanently stretched or
wound in the opened condition to provide an easily bendable
structure.
[0134] FIG. 4 shows an enlarged sectional view of the pull/push
mechanism of the catheter handle 4. The proximal end of the inner
guide tube 9 is seated on the catheter handle nose 15 which is
attached to an end of block or body 113 of handle 4. The
tension/compression members 11 and 12 are each fixed at one end to
the distal end of the guide tube 9 in the region 10. The other end
of each of the tension/compression members 11 and 12 is attached to
one of the pull/push length adjuster units 16 and 17 which are
slidingly mounted in grooves or slots 114, 115 mounted in block
113. With this arrangement, the distal portion 10 of the inner
guide tube 9 can be formed into a curved configuration by user
movement of the manual actuator member 18 in either transverse
direction as indicated by the dashed outline in FIG. 4 about pivot
pin 19 by which actuator 18 is mounted to block 113 in a
through-slot 116.
[0135] FIG. 5 shows an exploded view of the pull/push mechanism
removed from the catheter handle block 113. Upon movement of
actuator 18 the mechanism 4 is operative for applying tension to
one of the tension/compression members 11, 12, and thereby
affecting curvature formation at the distal portion L of the
catheter of this invention. In one embodiment, this pull/push
mechanism comprises two symmetrically coupled slider-crank
linkages, hereinafter described, that share the actuator member 18
which is preferably formed into a circular segment or delta shape
with a hollowed out portion 115 formed therearound.
[0136] Referring to FIGS. 4 and 5, the actuator 18 is disposed
freely within slot 116 of the handle block 113. The proximal apex
of this actuator 18 is hinged within the proximal front end of the
handle housing block 113 by a pin 19 received through aperture 117
in actuator 18. A pair of connecting rods 20 and 21 are received in
the hollowed-out portion 115 formed in actuator 18 and are
independently and symmetrically hinged each at one end through
aperture 120, 121 respectively to the actuator 18 by pins 22 and 23
respectively, received through aperture 118, 119 formed in actuator
18. The opposite ends of the connecting rods 20 and 21 are each
independently hinged each to an end of two separate and identical
slider links 16 and 17 by pins 26 and 27 respectively. Pin 26 is
received in aperture 122 in slider 16, with pin 26 passing through
aperture 123 in rod 20; and, pin 27 is received in aperture 124 in
slider 17, and pin 27 passes through aperture 125 in rod 21. The
end of rod 20 pivoted by pin 26 is received and articulated in a
slot 126 formed in slider 16; and, the end of rod 21 pivoted about
pin 27, is received and articulated in a slot 127 formed in slider
17.
[0137] Referring to FIGS. 4 and 5 the slider links 16 and 17 each
contain a pull/push member length adjuster unit indicated generally
at 24 and 25 respectively.
[0138] Referring to FIGS. 4, 6b, and 6c, one of the pull/push or
tension/compression members 12 is shown as extending through hollow
115 in actuator 18 and is connected to slider 17; and, pull/push
member 11 extends through hollow or slot 115 and is connected to
slider 16.
[0139] Referring to FIGS. 7a 7b, 7c, and 7d, one of the slider
blocks 16 is illustrated with its associated pull/push member
length adjuster unit 24 and its sub-components. The pull/push
member length adjuster 24 is disposed in a slider block 16 having a
longitudinally extending blind cylindrical cavity 28.
[0140] A generally cylindrical rod or adjusting member indicated
generally at 24 with an internally threaded hole or bore 32 formed
in the right end thereof is slidingly disposed freely within the
cavity 28 formed therein. The longitudinal position of rod 24 with
respect to the slider block 16 can be adjusted by the adjusting
screw 34 threaded into bore 32. A pull/push member fastener 36
fixes the proximal end of a pull/push member 12 (not shown in FIGS.
7a-7d) to rod 24. FIG. 7d shows an enlarged view of the typical
hinged attachment between one end of the connecting rod 20 and
slider block 16 by pin 26. The function of each individual and
independent pull/push member length adjusters such as adjuster 24
is to independently remove the slack from the corresponding
pull/push member 11, 12 that extends from catheter distal portion
to the catheter handle 4.
[0141] Referring to FIG. 8, actuator member 18 is shown in solid
outline and moved counterclockwise from the neutral position of
FIGS. 1 and 4. In the position shown in FIG. 8, rod 20 has moved
slider 16 rightward pulling on tension/compression member 12. Rod
21 has moved slider 17 leftward pushing on member 11. The distal
portion of the catheter of this invention can simultaneously be
curved to different radii of curvature and retained at the desired
curvature by a single action of the operator's finger. The
slider-crank pull/push mechanism of the catheter handle of this
invention operates near its "top-dead-center" or aligned position.
An inherent property of a slider-crank mechanism operating near its
top-dead-center position is a high-gain force amplification between
the input force on the crank link or actuator 18, and the output
force on the slider link. Therefore, catheter of this invention
requires a low actuating force on the actuator 18, transmitted
through the crank link, for assuming a full range of pull on one of
the members 11, 12 for affecting curvature at the distal portion of
the catheter. Any curvature formed at the catheter distal portion
by this mechanism will retain its configuration. This is because
the elastic potential energy stored in the deflected distal portion
of the catheter cannot provide a sufficient pull on the tensioned
members 11 or 12 as the case may be to move the crank link and thus
actuator 18 to disturb the assumed configuration of the
slider-crank mechanism which is near the "top-dead-center".
[0142] The geometric shape and dimensions of the delta-shaped
actuator 18 are designed to comfortably fit between the thumb and
index fingers of an operator's hand. The relative magnitudes of
these geometric dimensions, crank length (distance between pin 19
and pins 22, 23) and the length of the connecting rods 20 and 21
are determined such that a comfortable range of actuator 18
rotation in two opposite directions results in formation of the
full range of curvature, in opposite directions, at the distal
portion of the catheter. It will be understood that rotation of
actuator 18 in one direction is affected by the user's thumb of the
hand grasping the handle 113; and, rotation of actuator 18 in the
opposite direction is affected by at least one other finger of the
same grasping hand.
[0143] Referring to FIG. 8 the rotation of link 18 in a
counterclockwise direction to the position shown in solid outline
has caused the rectilinear displacements of slider blocks 16 and 17
in two opposite directions, i.e. slider 17 has moved to the left
and slider 16 has moved to the right. The movement of actuator 18
by the user to the position shown in solid outline FIG. 8 affects
formation of a curvature in a counterclockwise direction, at the
distal portion of the catheter, as the result of tension in the
pull/push member 12. It will be understood that a clockwise
curvature formation can be achieved at the distal portion of the
catheter when the manual actuator 18 is rotated in a clockwise
direction to the position shown in dashed outline in FIG. 8 which
causes slider block 16 to be moved to the left and slider block 17
to be moved to the right when links or rods 21, 20 are moved to the
positions shown respectively in dashed line.
[0144] Referring to FIGS. 9, 10, 11, 12, and 13 an alternative
embodiment 4' of the catheter handle is shown with a cam-follower
type pull/push mechanism for affecting formation of curvature at
the distal portion of the catheter upon movement of actuator 128.
The pivoted delta shaped actuator 128 is disposed to pivot freely
about pin 43 within the handle 113'.
[0145] Referring to FIG. 10, the mechanism of handle 4' comprises
two symmetrically coupled followers 40 and 41 disposed for sliding
movement on block 113' and with a single rotating cam 42 as the
driver. The cam 42 is rigidly attached to the apex of the
delta-shaped actuator 128 for rotation therewith. The center 44 of
cam 42 is pivoted within the catheter handle body 113' about a pin
43.
[0146] The two sliding followers 40 and 41 are driven by cam 42.
Each of the sliding followers 40 and 41 includes an adjusting screw
45 and 46 respectively. The tip of each of these adjusting screws
45, 46 are anchored to the cam profile and provides the contacting
point between the followers 40 and 41 and the profile of the cam
42. The distal ends of pull/push members 11 and 12 are individually
fastened to the corresponding followers 40 and 41 respectively by
the screws 47, 48 threaded respectively into followers 41, 40. The
slack in each pull/push member can independently be removed by
adjusting the screws 47 and/or 48.
[0147] Each of the two followers 40 and 41 slides freely, in one of
the straight grooves 49 and 50 respectively, provided in the
catheter handle 113'.
[0148] Referring to FIG. 11 the actuator member 128 is shown
rotated counterclockwise from the position shown in FIG. 10,
wherein cam 42 has caused rectilinear displacements of the two
followers 40 and 41 in opposite directions. Follower 40 has been
moved rightward tensioning pull/push member 12; and follower 41 has
been moved leftward pushing on pull/push member 11. This movement
of followers 40, 41 results in formation of a curvature, in a
counterclockwise direction, at the distal portion of the catheter.
It will be understood that a clockwise curvature formation can be
achieved at the distal portion of the catheter when the manual
actuator 128 is rotated in a clockwise direction to the position
shown in dashed outline in FIG. 11.
[0149] Referring to FIG. 12 an alternative arrangement of the
actuator handle is shown generally at 4", having a handle 113" and
wherein the user actuator member comprises a circular disk-shaped
actuator 51 which is attached to cam 42 in a torque-transmitting
arrangement. Cam 42 is shown in the neutral position in FIG. 12. It
will be understood that user rotation of actuator disk 51 rotates
cam 42.
[0150] Referring to FIG. 13, the actuator disk 51 has been rotated
in a counterclockwise direction as indicated by the arrow to place
cam 42 in the position shown in solid outline in FIG. 13. In FIG.
13, follower 40 has been moved rightward from the position of FIG.
12, tensioning or pulling member 12; and follower 41 has been moved
leftward from the FIG. 12 position, resulting in pushing on member
11.
[0151] Referring to FIG. 14 a further alternative embodiment of the
actuator handle is shown generally at 4'" for the catheter of this
invention wherein handle or body 130 has a groove or through-slot
132 with a pair of parallel oppositely disposed sliders 134, 136,
disposed therein, each having a rack gear formed thereon as denoted
respectively by reference numerals 138, 140. Rack gears 138, 140
are engaged on opposite sides of a common pinion gear 142. Pinion
142 rotates freely within the catheter handle 130 about pin 144
secured through body 130. Each slider 134, 136 includes a pull/push
member anchoring or attachment screw 146, 148 to which one end of
pull/push members 11, 12 are attached respectively. The apex of a
delta-shaped manual actuator 150 is fixed to the pinion 142 in
torque transmitting arrangement and is shown in the neutral
position in FIG. 14.
[0152] Referring to FIG. 15 the manual actuator 150 is shown
rotated counterclockwise from the position of FIG. 14, resulting in
the rectilinear displacements of the slider 136 to the left and
slider 134 to the right, pulling on pull/push member 12 and pushing
on pull/push member 11. The proximal ends of the pull/push member
11 and 12 are fixed to the sliders 136, 134 respectively by
fasteners such as screws 146 and 148. It will be understood that
the distal end of the pull/push members 11 and 12 are fixed to the
distal ends of the elongated inner guide tube 9. It will be also
understood that the actuator 150 may also be moved in the clockwise
direction to the position shown in dashed outline in FIG. 15,
resulting in opposite movement of slider 134, 136. With either
counterclockwise or clockwise rotations of actuator 150 the
rectilinear displacement of the slider racks 134, 136 is in
opposite directions and results in formation of curvature at the
distal portion of the catheter.
[0153] Referring to FIG. 16(a), another embodiment of the actuator
handle is indicated generaly at 4"", wherein pinion gear 142 is
attached to a circular actuator 152 in torque transmitting
arrangement.
[0154] Referring to FIG. 16(b), as the user rotates actuator disk
152 in a counterclockwise direction as shown by the arrow slider
136 is moved leftward, and slider 134 is moved rightward from the
neutral position shown in FIG. 16(a).
[0155] Referring to FIG. 17, another alternative embodiment has the
handle assembly that is indicated generally at 154. Handle assembly
154 includes an electromechanical battery operated drive system
that is substituted for the manually actuated pull/push mechanism
of the embodiments 4-4"". The embodiment 154 comprises two main
subsystems indicated generally at 60 and 61. The first sub-system
60 of the embodiment 154 is the "lower" portion of the catheter
handle that includes:
[0156] a cylindrical housing 62, having disposed therein a battery
63;
[0157] an electrical motor 64, which is connected to battery 63
disposed at the right hand end of housing 62;
[0158] a speed reduction gear box 65, driven by motor shaft 156,
and which has an output drive shaft 66;
[0159] a multi connector junction plug 67 is disposed on the front
end of the housing 62; and,
[0160] an electronic module 68 is provided on this end of housing
62 adjacent to battery 63 for receiving computer and/or
tele-communication signals. Battery 63 can either be disposable or
re-chargeable.
[0161] The second sub-system 61 has a multi connector proximal end
jack 69 disposed in the right hand end of housing 73. All
electrical wires of the catheter, including the electrode
conductors are terminated to the terminals (not shown) of jack 69.
The corresponding electrical leads of sub-system 60 are terminated
at terminals (not shown) of plug 67.
[0162] The electrical motor 64 and motor speed reduction gear box
65 are disposed within the cylindrical housing 60 adjacent the left
hand end. The coupling drive shaft 66 extends from the gear box 65
through a cylindrical collar 70 in the left end of the housing 62.
The drive shaft 66 can freely rotate within the front end collar 70
of the housing 62. The end of the drive shaft 66 is coupled to the
left hand end 71 of the core 72 of the sub-system 61. In operation
either clockwise or counterclockwise rotation of the drive shaft 66
results in driving core mechanism 72 and a corresponding curvature
formation respectively at the catheter distal portion.
[0163] The second sub-system 61 of the embodiment 154 comprises the
front or left hand portion of the catheter handle end and
includes:
[0164] a cylindrical housing 73;
[0165] a manual back-up actuator 74 in the form of a tubular member
disposed concentrically over housing 73;
[0166] a motor control switch 75;
[0167] the multi connector junction jack 69 is disposed inside the
right hand end of the cylindrical housing 73;
[0168] a connecting rod or pin 76 interconnects manual drive
actuator 74 to core 72 through a slot 82 formed in housing 73;
[0169] a front bearing support 77 is disposed in housing 73
adjacent the left end thereof;
[0170] a rear bearing support 78 is disposed in housing 73 adjacent
the right hand end thereof; and,
[0171] an angular displacement sensor 79 is disposed in housing 73
and located at the right hand end thereof for sensing rotation of
core 72 with respect to housing 73 of sub-system 61.
[0172] The core 72 of sub-system 61 includes two identical
pull/push member length adjusters 158, 160 which are each
respectively connected to one of the pull/push members 11, 12 of
the catheter 1. These adjusters are disposed, side-by-side, and
parallel to the longitudinal axis of the housing 73, within and
near the surface of the cylindrical solid portion of the core 72.
The core 72 of the sub-system 61 has a left end shaft 80 extending
therefrom and a right end shaft 81 extending therefrom in a
direction opposite shaft 80 and aligned therewith. Shaft 80, 81 are
supported by rotary bearings 77 and 78 respectively disposed in
housing 73; and thus, the core 72 can freely rotate within the
housing 73 about its longitudinal axis.
[0173] A backup manual actuator 74 comprises a short cylindrical
tube that is disposed over the front portion of the housing 73 and
can freely rotate about the longitudinal axis of the housing 73. An
actuator slot 82, extending circumfrentially and perpendicular to
the longitudinal axis of housing 73, is provided on the upper half
of the housing 73. The backup manual actuator 74 is linked to the
front portion of the core 72 with connecting rod or pin 76 through
slot 82. The width of the slot 82 is chosen to guide but permit
free movement of pin 76. The core 72 can thus be rotated about its
longitudinal axis with respect to housing 73 of sub-system 61 by
the rotation of the backup manual actuator about the same axis.
[0174] It will be understood that the proximal end of each
pull/push member 11 and 12 is fastened to a corresponding one of
the pull/push member length adjusters 158, 160 by screws 162, 164
respectively.
[0175] Rotation of core 72 about its longitudinal axis will pull
one of the pull/push members 11 or 12, and compresses the other
one, resulting in formation of curvature at the distal portion of
the catheter 1.
[0176] The multi connector junction jack 69 and multi connector
junction plug 67 serve as both the mechanical and electrical
coupling between the sub-systems 60 and 61.
[0177] When sub-systems 60 is connected to sub-system 61, the left
end of the drive shaft 66 is engaged with the right hand end of
core 72. The motor can be energized and controlled for forward and
reverse rotation by a switch 75 provided on the exterior of housing
73. As the motor 64 is activated, the drive shaft 66 will rotate
the core 72 which results in formation of curvature at the distal
portion of the catheter. Angular displacement sensor 79, disposed
in the housing 61, is employed to provide predetermined limits for
the angular rotation of core 72 as an indication of the radius of
curvature at the distal portion of the catheter. The actuator or
servomotor driven cardiac catheter handle 154 of FIG. 17 can also
be controlled remotely via computer and/or tele-communication
systems and thus has application for various other cardiac catheter
procedures.
[0178] Referring to FIG. 18 the servomotor operated
electromechanical catheter handle 154 is shown as a complete
assembly with its two subassemblies 60 and 61 connected together
with plug 67 engaging jack 69 as shown in dashed line.
[0179] Referring to FIG. 19 the distal portion of a further
embodiment of the catheter of this invention indicated generally at
170 and is shown in the curved condition. The embodiment of FIG. 19
is configured such that it can be employed for cardiac ablation and
intra-cardiac mapping procedures.
[0180] This embodiment indicated generally at 170 in FIG. 19 is a
modified version of the catheter 1 presented in FIG. 1 of this
invention. The modification is applied on the catheter distal tip
electrode 5 of the FIG. 1 embodiment and is described as
follows.
[0181] Referring to FIG. 19 an electrical heating element 100 is
disposed within the distal tip cup-shaped electrode 172. The
heating element 100 is energized by a battery disposed in the
catheter handle 4 or by an external electrical power supply (not
shown). The temperature of the distal electrode is controlled by
adjusting the electrical current flow through the heating element
100. Electrical lead wires 101 and 102 are connected to the heating
element 100 and extend from the heating element 100 within the
interior of tubular body 2 to the proximal end and outwardly to the
power supply and temperature control switch (not shown).
[0182] The embodiment 170 includes an additional annular reference
electrode 103 on the catheter main exterior tube 2 for a uni-polar
application of the catheter during intra-cardiac mapping
procedures. In addition, the catheter 170 may include a blood-clot
sensor or detector (not shown) and a temperature indicator (not
shown) in the catheter handle 4. The purpose of blood clot sensor
is to stop or reduce the delivery of electrical energy to the
heating element during ablation procedures.
[0183] Referring to FIGS. 20a through 20d a further embodiment 180
of the catheter of the present invention is illustrated and has the
feature that the blood contacting portions are disposable; and,
thus, the embodiment 180 is particularly suitable for cardiac
electrophysiology/ablation procedures. The embodiment 180 is a
modified version of the catheter presented in FIG. 1 of this
invention. The modification is applied in two parts. The first
modification pertains to the shape of the distal tip electrode 176
and its connection to the main exterior tube 172 of the catheter
which, along with a proximal end connector 181 having internal
connector rings 188 comprises the blood contacting components or
sub-assembly indicated generally at 166. The second modification
involves the method of connecting the subassembly 166 of blood
contacting components i.e. a main exterior tube 172, spaced
electrodes 174 and distal electrode 176 to the non-blood contacting
components indicated generally at 168 comprising an inner guide
tube 178 and catheter handle indicated generally at 182.
[0184] The first modification is illustrated in FIG. 20a. FIG. 24
shows the modified distal electrode 176 employed in the FIG. 20a
embodiment as having a cup-shaped configuration. The distal
electrode 176 is formed as a cylindrical shell with a hemispheric
dome 110 on the closed end and a plurality, preferably four, of
circumfrentially spaced prongs 111 extend outwardly in an axial
direction from the other open end of the cup-shaped distal
electrode 176.
[0185] Referring to FIG. 25 the cup-shaped electrode 176 is sleeved
partially over the distal portion of the main exterior tube 172 of
the catheter. The prongs 111 are bent inwardly perforating the wall
of the main exterior tube 172, extending inwardly and again bent
over the inner wall of the main exterior tube 172 to form a
"stapled-type" connection between the cup-shaped distal electrode
176 and the main exterior tube 172. At least one wire 112 is
wrapped around one of the prongs 111 and secured to the inner wall
of the main exterior tube 172 to provide electrical connection to
electrode 176 and also provides a redundant securement to tube
172.
[0186] Referring to FIGS. 20a-20d, the second modification for the
disposable catheter 180 is described as follows. The two
sub-assemblies, namely the blood contacting subassembly 166 and
non-blood contacting sub-assembly 168 of catheter 180 of this
invention are individually fabricated such that they can function
independently as intended.
[0187] Referring to FIG. 20a, the first sub-assembly or blood
contacting unit 166 of this embodiment 180 comprises of the main
exterior tube 172 of the catheter, the spaced surface electrodes
174 and distal electrode 176, the electrical wires of the surface
electrodes and the combined electric coupling and structural
connector 181. All electrical wires of the catheter tip electrodes
174, 176 terminate to the coupling 181.
[0188] Referring to FIG. 20b the second non-blood contacting
sub-assembly 168 of embodiment 180 is illustrated. Second
sub-assembly 168 comprises the inner guide tube 178, a combination
electrical connector and structural coupling 183, a catheter handle
indicated generally at 182 and catheter electrical lead connector
end plugs 184. The non blood contacting sub-assembly 168 can
readily be coupled to the blood contacting subassembly 166; and,
the two can be locked together by the couplings 181 and 183 which
may be threaded or quick-lock type to form a assembly 180 that can
function as a complete catheter.
[0189] Referring to FIG. 20c the coupling of the two sub-assemblies
of the catheter of this invention is shown with guide inner tube
178 of subassembly 168 partially inserted into tubular casing 172
of sub-assembly 166. The coupling action of the two sub-assemblies
166, 168 can also be done during the cardiac
electrophysiology/ablation procedures by the physician. This allows
the physician to select from variety of second non-blood contacting
actuator sub-assemblies 168 that offer different distal portion
curvature configurations for the same blood contacting sub-assembly
166. In the embodiment 180, the disposable segment of the catheter
comprises only the blood contacting sub-assembly 166 shown
respectively in FIG. 20a.
[0190] Referring to FIG. 20d, the catheter of embodiment 180 is
fully assembled with connector 181 engaged with connector 183. It
will be understood that the electrical lead from each of the
electrodes 174, 176 is connected to one of the electrical terminal
rings 186 on connector 183. Each of the rings 186 makes electrical
contact with a correspondingly located terminal annular 188
provided in connector 181 of sub-assembly 166.
[0191] The catheter of this embodiment 180 can thus significantly
reduce the price of cardiac catheters and thus an overall cost
reduction of the cardiac electrophysiology and ablation
procedures.
[0192] Referring to FIG. 21 the external electrical connector 186
of actuator handle sub-assembly 182 of FIGS. 20b, 20c, and 20d is
shown where each of the electrical connector 186 has an end of one
of the lead wires 230, 232, 234, 236, attached thereto. It will be
understood tat each of the leads 230-236 has its opposite end
connected to one of the connectors 184 externally of handle
182.
[0193] Referring to FIG. 22 the electrical connector 181 of
disposable blood contacting subassembly 180 of FIGS. 20a, 20c, and
20d is shown enlarged with an internal tubular sheath or liner 238
defining an annular space 240 between liner 238 and the body of
connector 181. The proximal end of the main exterior tube 172 is
received and retained, as for example by weldment into a reduced
diameter neck 242 formed on connector body 181, Liner 238 has a
reduced diameter neck 243 which extends a predetermined distance
into main exterior tube 172. A plurality of axially spaced
electrical terminals 244, 246, 248, 250 are disposed on the inner
periphery of liner 238 with each of its terminals 244-250 having
portions thereof extending outwardly through the wall of liner 238
and into the annular space 240. A plurality of electrical leads
252,254, 256, 258 is received in the annular space 240 and each has
respectively one end thereof connected to one of the terminals
244-250. Each of the leads 252-258 extends through annular space
between liner 238 and the inner periphery of main exterior tube 172
and continues to the distal portion of tube 172. It will be
understood that each of the leads 252-258 is respectively connected
to one of the electrodes 174, 176 on the blood contacting
sub-assembly 166.
[0194] Referring to FIG. 23, connectors 181, 183 are shown
assembled with the ring. electrical connectors 186 of connector 183
each making contact with one of the connector terminals 244-250 for
providing electrical continuity between electrical leads pairs 230
and 254, 232 and 252, 234 and 256, 236 and 258 thereby connecting
each of the external connectors 184 with one of the electrodes 176
174 on the distal portion of the disposable blood contacting
subassembly 166.
[0195] Referring to FIG. 26 an alternative embodiment indicated
generally at 190 of the catheter handle sub-assembly is shown in
exploded view without the handle body with a Scotch-Yoke type
pull/push mechanism for affecting formation of curvature at the
distal portion of the catheter upon movement of the actuator member
192. The preferably delta shaped actuator 192 is disposed to pivot
freely about pin 194 within the handle's body (not shown). It will
be understood that member 192 may be disposed for pivoting in a
handle slot in a manner similar to actuator member 18 of FIG.
1.
[0196] Referring to FIGS. 26 and 27, the mechanism of handle 190
comprises two symmetrically coupled sliders 196 and 198 disposed
for sliding movement in groove 200 formed in handle body 202 and
with the single rotating actuator 192 as the driver thereof. The
sliders 196 and 198 are linked to the delta-shaped actuator 192 by
non-articulating pins or links 204 and 206.
[0197] Referring to FIG. 26 pins or links 204, 206 are formed
generally at a right angle at one end, with the ends each received
in a transverse bore provided in the side of sliders 196, 198 with
links 204, 206 extending from sliders 196, 198 outwardly in the
direction of sliding movement. The opposite or free ends of links
204, 206 are also formed at right angles in a common direction
orthogonal to the links-receiving bores in the sliders 196, 198 and
as denoted by reference numerals 208, 210. The links 204, 206 are
thus non-articulatable in a center plane passing through both
sliders 196, 198.
[0198] The actuator 192 has a pair of spaced slots 212, 214
elongated in a direction transverse to delta-shaped actuator 192.
Link end 208 is received in slot 212; and, link end 210 is received
in slot 214. It will be understood that user movement of the
actuator 192 in the direction of the block arrows in FIG. 26 will
cause relative movement of the link ends into slots 212, 214 and
will result in pulling one and pushing the other of the sliders
196, 198 in groove 200 of body 202.
[0199] The proximal ends of tension/compression (pull/push) members
11 and 12 are individually received in a closely fitting tubular
sleeve denoted respectively 216, 218 which are in turn received
individually in a longitudinal bore denoted respectively 220, 224
provided in each of the sliders 196, 198. The sleeves 216, 218 may
be secured to pull/push members 11, 12 respectively by weldment if
desired, as, for example by soldering or brazing. The sleeves 216,
218 and the proximal ends of members 11, 12 are secured
respectively in slider bores 220, 224 by engagement with set screws
torqued into threaded cross holes provided in sliders 196, 198, one
such cross hole is visible in FIG. 26 at 230.
[0200] Each of the two sliders 196 and 198 slides freely, in the
straight groove 200 provided in the catheter handle 202.
[0201] Referring to FIG. 27 the actuator member is shown rotated
counterclockwise from the position shown in FIG. 26, wherein
actuator 192 has caused rectilinear displacements of the two
sliders 196 and 198 in opposite directions. Slider 196 has been
moved leftward pushing member 11; and slider 198 has been moved
rightward pulling member 12. This movement of sliders 196, 198
results in formation of a curvature, in a counterclockwise
direction, at the distal portion of the catheter. It will be
understood that a clockwise curvature formation can be achieved at
the distal portion of the catheter when the manual actuator 192 is
rotated in a clockwise direction to the position shown in dashed
outline in FIG. 27.
[0202] Referring to FIGS. 28 and 29, an alternative preferred
embodiment of the non-blood contacting actuator 168 of FIG. 20b is
shown generally at 260 with an inner guide tube 262 formed of
helically wound wire similar to inner guide tube 178 of FIG. 20b.
The distal end of inner guide tube 262 has a tip plug or member 264
attached securely thereto, such as by weldment. A pair of pull/push
or tension/compression members 268, 266 are received in tube 260,
with a portion of each denoted 266', 268' integrally flattened to a
ribbon-like configuration, with the end of each ribbon secured to
tip 264 as by weldment. A guide bushing 270 has a rectangular
through bore 271 formed therein has the ribbons 266', 268' slidably
received therein, with guide bushing 270 adjacent to the proximal
end of ribbon-like portions 266', 268'. The guide bushing 270 is
secured, such as by weldment, to the distal end of the inner guide
tube 261 with contacting coils (closed windings).
[0203] An annular collar or sleeve member 272 is received over
ribbon-like portions 266', 268' and serves as a kinematic junction
of the ends of 266', 268'. The collar 272 is secured, such as by
weldment, to both ribbons 266', 268' at a predetermined distance
between the guide bushing 270 and tip plug 264. The actuator 260 is
shown in relaxed or neutral condition in FIG. 28.
[0204] Referring to FIG. 29, tension has been applied to member 266
causing ribbon 266' to pull on collar 272 bending the 262 between
guide bushing 270 and collar 272; however the portion of tube 262
between collar 272 and tip 264 remains straight or
un-deflected.
[0205] It will be understood that the inner guide tube 261 of FIG.
29 or 9 of FIG. 3a of the present invention is not loaded in
compression when one of the members 266, 268 of FIG. 29 or 11, 12
of FIG. 3a is tensioned. Unlike the known catheters, the catheter
of the present invention transmits the compression loading of the
kinematic junction directly to the one of push/pull members 266,
268 of FIG. 29 that is not being tensioned by the manual actuator
and does not use a separate compression strut member to transmit
compression load to the inner guide tube as in the case of known
catheters. It will be understood that in the embodiment of FIGS. 28
and 29 the kinematic junction comprises of the weldment of collar
272 to 266', 268'; and in the embodiment of FIG. 3a the kinematic
junction comprises the attachment of the pull/push or
tension/compression members 11', 12' to the distal end of portion
10 of inner guide tube 9.
[0206] The present invention thus provides a low cost cardiac
catheter which has a disposable blood-contacting segment removable
from the actuator assembly which is re-useable. The actuator
utilizes a pair of tension/compression members which are flattened
integrally at the distal end region for improved deflection
characteristics. The actuator handle is grasped in the user's hand
and catheter distal region deflection in one direction is affected
by movement of a handle actuator member in one direction by the
user's thumb; and catheter deflection in the opposite direction is
affected by movement of the handle actuator member in the opposite
direction by the other finger(s) of the same hand.
[0207] FIG. 30 is a view showing the actuator handle assembly as
grasped by the user's hand.
[0208] Referring to FIGS. 31 and 32, another embodiment of the
catheter of thee invention is indicated generally at 300 and has a
solid distal electrode that in the present practice of the
invention has been formed satisfactorily from platinum material and
is denoted by reference numeral 302. The electrode 302 has the
distal ends of a pair of tension/compression members 304, 306
secured therein as for example by weldment which in the present
practice of the invention comprises a brazed joint 308. It will be
understood that the distal portions of the tension/compression
members 304, 306 have a generally flattened rectangular transverse
cross-sections as illustrated in FIG. 32.
[0209] A spacer means 310 is disposed between the flattened ends of
tension/compression members 304, 306 in the present practice of the
invention. The spacer means 310 comprises a wave-shaped flat spring
having a generally rectangular transverse cross-section with an end
thereof secured between the tension/compression members 304, 306 in
a kinematic junction indicated generally at 312. The kinematic
junction 312 is formed by a sleeve 314 which in the present
practice of the invention is formed of stainless steel tubing
received over the tension/compression members at the kinematic
junction having the end of the wave-shaped spring 310 and is
secured and formed by weldment which in the present practice of the
invention comprises brazing as denoted by reference numeral 316. It
will be understood that the spacer 310 serves only to maintain the
transverse or lateral spacing of the tension/compression members
304,306 on the side of kinematic junction 312 away from the distal
electrode 302. It will be understood that except for the end of
spacer 310 which is brazed into sleeve 314, the wave-shaped flat
spring 310 is otherwise free-floating between the
tension/compression members 304, 306.
[0210] It will be understood that the tension/compression members'
transition to a round or wire-like configuration is denoted by
reference numerals 304' 306' in a manner similar to the embodiment
of FIGS. 2b and 3a of the present invention. In te embodiment of
FIGS. 31 and 32, a thin wall plastic tubing 318 is received over
the distal flattened portions of the tension/compression members
304, 306 and the plastic tube is received over, in closely fitting
engagement, an annular sleeve or collar 320 secured to the weldment
or brazed joint of the distal electrode. In the present practice of
the invention, the collar 320 is formed of stainless steel
material. The plastic tube 318 extends over the round cross-section
portions 304',306' of the tension/compression members; and, the
tube 318 also extends over the distal end of an inner guide tube
322 wich in the present practice of the invention comprises a
closed coil stacked helical spring member.
[0211] A thin wall preferably stainless steel tubular member 324 is
received over the tension/compression members 304', 306' and the
tube 324 has one end thereof crimped to a flattened cross-section
as denoted by reference numeral 326 and the member 324 serves to
constrain the tension/compression members from twisting or rotation
with respect to the outer casings 325 and 330 during flexing of
distal portion of the catheter. An outer blood-contacting casing
comprising a tubular flexible plastic member 325 has the distal end
thereof is attached to a reduced diameter portion distal electrode
302 and extends over the tube 318 and has the opposite end thereof
received over a thin-wall short annular sleeve member 328 whien
serves to join the outer casing member 325 with the outer casing
330 which is re-enforced with braided material as denoted by
reference numeral 332. With reference to FIG. 31, a plurality of
annular electrodes are received over the outer periphery of the
casing member 325 and are disposed in spaced arrangement therealong
with each of the electrodes having an electrical wire lead member
connected thereto as denoted by reference numeral 334,336 for the
electrodes and 338,340 for the wire leads in FIG. 31.
[0212] It will be understood that the catheter 300 is intended to
be operated by the handle mechanism illustrated in FIG. 1 wherein
the slider members are connected to the tension/compression members
304, 306 such that movement of the actuator causes one slider to
tension one of the members 304, 306 and the other of the members is
placed in compression; and, reversed movement of te actuator
wherein the handle causes the other of the tension/compression
members to be tensioned and the one to be placed in
compression.
[0213] Referring to FIGS. 33 through 37, another embodiment of the
electrophysiology/ablation catheter of the present invention is
indicated generally at 400 and has a construction generally
identical to tat of the catheter 300 of FIG. 31 with the exception
that the inner guide tube 302 is formed of plastic material and has
two generally circular longitudinally extending lumens 404, 406
formed thereto to which are received the tension/compression
members 408, 410.
[0214] It will be understood that in the embodiment 400, a
tension/compression members 404, 406 have flattened distal portions
404' and 406' as illustrated in detain in FIGS. 36 and 37; and, the
embodiment 400 also employs the spacer means comprising a
wave-shaped flat spring 416 with one end thereof secured in a
kinematic junction 426 in a manner identical to that of embodiment
300 of FIG. 31.
[0215] It will be understood that in the embodiment 400, the inner
guide tube is received in the end of the thin wall plastic tube 418
which corresponds to the tube 318 in the embodiment of FIG. 31.
[0216] Referring to FIGS. 39 and 58, the embodiment 400 of the
present invention is illustrated in exploded view in the preferred
form wherein the flexible plastic tube 418 has three (3) lumens
formed therethrough with wave-shaped flat spring spacer 416
received through the central lumen and each of the
tension/compression members' flattened portions 404', 406' received
through a lumen disposed respectively on opposite sides of the
central lumen.
[0217] Referring to FIG. 39, the central lumen is denoted by
reference numeral 420 and the side lumens are denoted by reference
numerals 422 and 424. In the embodiment 400, the annular tube
member forming the kinematic junction is denoted by reference
numeral 426; and, the outer casing portion having te electrodes
thereon is denoted by reference numeral 428 and the braided portion
of the outer casing is denoted by reference numeral 430 and the
distal electrode is denoted by reference numeral 432.
[0218] In the embodiment 400, the flattened tube portion denoted by
reference numeral 434 is optional in as much as the construction of
the inner guide tube 402 is operative to prevent twisting of the
tension/compression members with respect to the outer casings 428
and 430.
[0219] Referring to FIG. 38, another embodiment of the catheter of
FIG. 33 is illustrated in longitudinal cross-section in its distal
portion and denoted generally at 500. The catheter 500 is identical
to the catheter 400 of FIG. 33 with the exception that sleeve or
annular member 502 forming the kinematic junction of the ends 504,
506 of the tension/compression members 505', 506' and the end of
the wave-shaped flat spring spacer 508 is spaced a distance further
from the distal electrode 510.
[0220] The kinematic junction 512 is formed by brazing in distal
ends of the tension/compression members 504, 506 and the distal end
of the wave shaped flat spring spacer 508 in the annular member
502. By virtue of the distance between the distal electrode 510,
and the kinematic junction 512 a region is created, between the
electrode 510 and kinematic junction 512, which remains un-deformed
during lateral deflection of the catheter by operation of the
actuator for pulling and pushing on the tension/compression members
504' and 506'. In the embodiment 500, an additional flexible tube
is inserted over the flexible tube 518 (which corresponds to the
tube 418) and the additional tube denoted by reference numeral 520
which provides additional stiffness to the region of the catheter
between kinematic junction 512 and the end of the tube 518 remote
from electrode 510.
[0221] Referring to FIGS. 40 and 41, another embodiment of the
invention is indicated generally at 600; and, the distal portion of
the catheter 600 is identical to the embodiment 300, 400 as
described hereinabove except the distal electrode of the catheter
600, denoted by reference numeral 602, has embedded therein a
heating element 604 to enable the catheter to be employed as an
ablation catheter. It will be understood that the heating element
604 has a pair of electrical power leads 606, 608 attached thereto
and which extend within the outer casing 610 to the proximal end of
the catheter and into the handle 612 for connection to a power
supply and temperature control module provided therein and denoted
by reference numeral 614 in FIG. 40.
[0222] The embodiment 600 of FIG. 41 also includes a temperature
sensor 616 embedded in the distal electrode 602, which is the
present practice of the invention may be a solid state junction
device which has leads 618, 620 extending within the casing 610 to
the proximal end of the catheter. The sensor 616 is intended for
use in remote monitoring of the temperature of the distal electrode
602 during ablation procedures.
[0223] Referring to FIGS. 42 and 43, an alternate version of the
embodiment 600 is illustrated wherein the catheter assembly
indicated generally at 700 as the construction thereof, identical
to the embodiment 600 with the exception that catheter of 700 does
not include a heating element in its distal electrode 702; and
instead, the temperature of the distal electrode 702 is controlled
by a radio-frequency power supply/control module that is external
to the catheter of 700.
[0224] It will be understood that a fiber optic temperature sensor
can be used instead of the solid state junction 716 in an alternate
embodiment of catheter 700; and, a fiber optic cable extends within
outer casings 706 and 707 to the proximal end of the catheter.
[0225] Referring to FIG. 44, another embodiment of catheter handle
is indicated generally at 800 and has the proximal end of the guide
tube 802 received in a tubular member 804 in a closely fitting
arrangement with the tension/compression members 806, 808 extending
from the proximal end of he guide tube 802 and through the tube
member 804 for connection to a pair of slider blocks 810 and 812
which corresponds in shape and function to the sliders 16 and 17 of
FIG. 5. The proximal ends of each of the tension/compression
members 806, 808 each have a closely fitting thin wall preferably
stainless steel tube 814, 816 received respectively thereover.
[0226] The proximal ends of the tension/compression members 806,
808 with their respective tubes 814, 816 are each secured in one of
the slider blocks 810, 812 by a set screw 818, 820 respectively
which deforms the thin wall of tubing 814, 816 and clamps the
tubing and the respective tension/compression members 806, 808 to
the slider blocks 810, 812.
[0227] Referring to FIG. 45, the embodiment 800 of catheter
embodies a friction brake member 822 contained in the handle 824 by
interior projection 826 which maintains the member 822 in
frictional contact wit the curved edge of the actuator 828 which
corresponds in shape and function to actuator 18 of embodiment of
FIG. 1. In the present practice of the invention the member 822 is
formed of elastomeric material to provide inherent spring
compression of the material against the curved edge of the actuator
828; and, the member 822 by virtue of the sliding friction on the
curved edge of the actuator 828 serves to retain the actuator 828
in its user selected position after movement from the neutral
position shown in FIG. 45.
[0228] Referring to FIG. 46, the embodiment of catheter 800
illustrated in FIG. 45 is shown with the actuator moved to a user
selected position for curving the distal portion of the catheter
wherein the member 822 has deformed resiliently to the position of
the curved edge of the actuator 828 but is maintaining frictional
contact therewith.
[0229] Referring to FIGS. 56 and 57, another version of the
frictional retaining member is illustrated in the embodiment
indicated generally at 900 wherein the actuator 902 corresponds to
the actuator member 828 of the embodiment 800; and, the curved edge
portion 904 of the actuator 902 has engaged therewith the end of a
spring loaded plunger 906 which is received in a tubular housing
908 which in turn has a compression spring 910 received therein for
biasing the plunger 906 in contact with the curved edge 904 of the
actuator 902. The tubular member 908 is disposed in the handle 912
between guide projections 914. It will be understood that the
plunger 906 serves the same function as the member 822 of the
embodiment 800 of FIG. 45.
[0230] Referring to FIG. 47, another embodiment of the catheter
handle is indicated generally at 4' wherein the slider 16' and 17'
have a wiper tube 290 attached thereto which is operative to vary
the electrical resistance in a potentiometer 292 for providing an
electrical indicator signal corresponding to the position of the
sliders 16', 17' from which the curvature of the distal portion of
the catheter may be calibrated for a catheter of known
parameters.
[0231] Referring to FIG. 48, a compressible collar or spool 296 is
received over the proximal portion of the braided exterior casing 2
wherein the collar 296 is in frictional sliding engagement with
braided exterior casing 2. The collar 296 is preferably formed of
soft elastomeric or spongy material. The user may press the collar
296 onto the braided outer casing for readily applying torque
thereon for twisting the braided outer casing. As shown by the
dashed outlines of FIG. 48, the member 296 may be moved by the user
longitudinally along the braided outer casing tube 2 of the
catheter for selecting the point of application of the user's
applied torque to the catheter's braided outer casing tube.
[0232] Referring to FIGS. 48 through 54, the technique for
installing one of the annular electrodes over the outer casing at
the distal portion of catheter is illustrated and will be described
hereinafter with respect to FIGS. 49 through 54. Referring to FIG.
49, an annular electrode 1000 has an electrical conductive lead
1002 attached to the interior periphery thereof and extending
outwardly therefrom. The flexible outer casing tubing 1004 has an
end thereof received over a rigid tubing such as 1008 which serves
as a part of a holding vise for the tubing 1004. The free end of
the electrical lead 1002 is then passed through an aperture 1006 on
the flexible outer casing tube 1004 and then is passed outwardly
through the end of the tubing 1008 as shown in FIG. 50.
[0233] Referring to FIG. 51, the electrode 1000 is then assembled
over the end of tube 1004 over a tapered portion as shown in FIG.
51.
[0234] The end of the tube 1004 received over tube 1008 is then
clamped and secured thereon by suitable clamping fixtures 1010,
1012 as shown in FIG. 52. The tube 1004 is then stretched such that
the electrode 1000 may be passed thereover and located over
aperture 1006 with the lead 1002 being fed through the end of
tubing 1008. It will be understood that the stretching or pulling
of tube 1004 as indicated by the arrow in FIG. 52 causes a
reduction in diameter of the tube 1004 which permits the electrode
1000 to be slipped thereover and be positioned over the aperture
1006. When the electrode 1000 is located at the desired position
over the aperture 1006, the electrical lead 1002 is pulled through
the end of the tube 1008 as shown in FIG. 53. When the electrode
1000 has been positioned at the desired position the pulling force
on the tubing 1004 is then released, the tubing 1004 expands to
engage the interior of the annular electrode 1000 and maintains the
electrode 1000 in a desired position on the tube 1004. The clamping
load of members 1010, 1012 are then released; the excess material
on the end of tube 1004 is then removed as shown in FIG. 54.
[0235] Referring to FIG. 55, a schematic view of the temperature
control of the distal electrode of the ablation catheter 600 of
FIG. 40 is illustrated in a standard feedback control
flow-chart.
[0236] Referring to FIG. 31, all electrodes disposed on the distal
portion of the catheter of this invention may be formed of
electrically conductive elastomeric material(s)
[0237] Although the present invention has been described
hereinabove with respect to the illustrated embodiments, it will be
understood that the invention is capable of modification and
variation and is limited only by the scope of the following
claims.
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