U.S. patent application number 09/729649 was filed with the patent office on 2001-10-18 for flexible electrode catheter and process for manufacturing the same.
Invention is credited to Abbate, Anthony, Griffin, Joseph C. III.
Application Number | 20010032006 09/729649 |
Document ID | / |
Family ID | 26864571 |
Filed Date | 2001-10-18 |
United States Patent
Application |
20010032006 |
Kind Code |
A1 |
Griffin, Joseph C. III ; et
al. |
October 18, 2001 |
Flexible electrode catheter and process for manufacturing the
same
Abstract
A process for manufacturing a flexible electrode catheter is
disclosed. The process involves coating the catheter with an
adhesive without affecting the integrity of the polymer substrate
of the catheter. The process includes the steps of corona plasma
treating a catheter, coating the catheter with an adhesive, baking
the adhesive on the catheter, creating radial indents, and removing
portions of the coating from the indented areas so that conduction
between the different electrodes is broken. Portholes are then
punched into the indented conductive areas and magnetic wires are
inserted through the catheter and wrapped around the indented
conductive areas. A small amount of formulated silver paint is then
placed around the coiled magnetic wires. The entire indent, which
includes the coiled wire and the area where the coating was
removed, is then filled in radially with an adhesive coating.
Inventors: |
Griffin, Joseph C. III;
(Atco, NJ) ; Abbate, Anthony; (Novato,
CA) |
Correspondence
Address: |
Norman E. Lehrer
1205 North Kings Highway
Cherry Hill
NJ
08034
US
|
Family ID: |
26864571 |
Appl. No.: |
09/729649 |
Filed: |
December 4, 2000 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60168905 |
Dec 3, 1999 |
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Current U.S.
Class: |
607/122 |
Current CPC
Class: |
A61N 1/05 20130101 |
Class at
Publication: |
607/122 |
International
Class: |
A61N 001/05 |
Claims
We claim:
1. A method for forming an electrophysiology catheter with at least
one electrode on the outer surface thereof comprising the steps of:
providing a catheter body having an elongated flexible tubular
member with an outer surface having a proximal end and a distal
end; forming a coating of an electrically conductive material on
said outer surface of said tubular member; forming a radial groove
of predetermined axial length in said outer surface in the area
within the coated area while maintaining the electrical
conductivity of said conductive material; removing at least one
portion of said coating within said groove so that at least two
coated portions result that are electrically insulated from one
another; forming a port hole in said groove in the area of said
conductive material to create communication between the interior
and exterior of said tubular member; extending an elongated
flexible wire through said tubular member from said proximal end
and out of said port hole; wrapping said wire around said coating
within said groove, and filling said groove with an adhesive filler
material to form a smooth substantially continuous outer surface on
said catheter.
2. An electrophysiology catheter with at least one electrode on the
outer surface thereof comprising: a catheter body having an
elongated flexible tubular member with an outer surface having a
proximal end and a distal end; an electrode in the form of a
coating of an electrically conductive material on at least a
portion of said outer surface of said tubular member; a radial
groove of predetermined axial length in said outer surface, a
portion of the surface of said groove being coated with said
electrically conductive material and being in electrical contact
with said electrode, another portion of said surface of said groove
being electrically insulated from said electrode; a port hole in
said groove in the area of said conductive material creating
communication between the interior and exterior of said tubular
member; an elongated flexible wire extending through said tubular
member from said proximal end and out of said port hole and having
its end wrapped around said coating within said groove, and an
adhesive filler material filling said groove to form a smooth
substantially continuous outer surface on said catheter.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional
Patent Application Ser. No. 60/168,905, filed Dec. 3, 1999.
BACKGROUND OF THE INVENTION
[0002] The present invention is directed toward a flexible
electrode catheter and more particularly, toward a process which
will provide an extremely flexible, versatile, and conductive
coating for electrophysiology catheters.
[0003] Currently, the electrophysiology industry uses stainless
steel, platinum, or gold as materials for the electrodes that
transmit electric signals between the catheter and cardiac tissue.
There are several disadvantages in using such rigid metal electrode
bands. For one, because of the electrodes'inflexibility, metal
electrodes can significantly affect the overall flexibility of the
catheter by constraining the electrode lengths and spacing between
individual electrode bands. Also, the methods used to fix the metal
electrodes to the catheter are usually time-consuming and can
damage the catheter in the process.
[0004] U.S. Pat. No. 5,433,742 to Willis discloses electrode bands
which are applied to the exterior surface of a cardiac catheter.
The bands may be sprayed onto the catheter. This patent, however,
does not provide electrodes with the flexibility necessary for
electrophysiology catheters.
SUMMARY OF THE INVENTION
[0005] The present invention is designed to overcome the
deficiencies of the prior art discussed above. It is an object of
the present invention to provide a flexible electrode catheter.
[0006] It is another object of the present invention to provide a
manufacturing process which provides a flexible, versatile, and
conductive coating for electrophysiology catheters.
[0007] It is a further object of the present invention to provide a
coating for a catheter which may be applied to the catheter via
atomization spraying without affecting the integrity of the polymer
substrate of the catheter.
[0008] In accordance with the illustrative embodiments
demonstrating features and advantages of the present invention,
there is provided a process for manufacturing a conductive adhesive
band electrode that is flexible and can be applied to a catheter
via atomization spraying. The process includes the steps of corona
plasma treating a catheter, coating the catheter with an adhesive,
baking the adhesive on the catheter, creating radial indents on the
coated surface of the catheter, removing portions of the coated
surface from the indented areas so that conduction between the
different electrodes is broken. Portholes are then punched into the
catheter and magnetic wires are inserted within the catheter and
wrapped around the indented conductive areas. A small amount of
formulated silver paint is then placed around the areas of coiled
magnetic wire. The entire indent, which includes the coiled wire
and the area where the coating was removed, is then filled in
radially with an adhesive coating.
[0009] Other objects, features, and advantages of the invention
will be readily apparent from the following detailed description of
a preferred embodiment thereof taken in conjunction with the
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] For the purpose of illustrating the invention, there is
shown in the accompanying drawings one form which is presently
preferred; it being understood that the invention is not intended
to be limited to the precise arrangements and instrumentalities
shown.
[0011] FIG. 1 illustrates the step of corona plasma treating an
exposed surface of a catheter tube of the present method;
[0012] FIG. 2 illustrates the step of applying an adhesive coating
to the exposed surface of the catheter tube;
[0013] FIG. 3 illustrates the step of curing the adhesive coating
on the catheter tube;
[0014] FIG. 4 illustrates the step of placing radial indents within
the coated surface and removing portions of the coated surface from
the indented areas of the catheter tube;
[0015] FIG. 5 illustrates the catheter tube after radial indents
have been placed on the coated surface and portions of the coated
surface have been removed from the indented areas;
[0016] FIG. 6 illustrates the step of punching portholes within the
catheter tube;
[0017] FIG. 7 illustrates the step of wrapping a conductor wire
around each indented conductive area of the catheter tube;
[0018] FIG. 8 illustrates the step of applying a coating over the
conductor wires that are wrapped around the catheter tube; and
[0019] FIG. 9 illustrates the step of filling the indented areas
with a polymeric material.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0020] Referring to the drawings in detail wherein like reference
numerals have been used throughout the various figures to designate
like elements, there is shown in FIG. 9 a flexible electrode
catheter constructed in accordance with the principles of the
present manufacturing process and designated generally as 10.
[0021] The flexible electrode manufacturing process essentially
includes first providing a plastic catheter tube 12 which is
cleaned with an alcohol swab and is then masked with a high
temperature masking tape. However, only an approximately one-inch
length 14 is required to be masked. The length 14 separates the
area on the catheter tube 12 where the electrode band will be
formed from the rest of the catheter. The catheter tube 12 is then
mounted into a computer automated processing machine 16 that is
designed to corona plasma treat the exposed surface or portion 18
of the tube 12. (See FIG. 1.)
[0022] Once the exposed surface 18 has been treated, a conductive
adhesive coating 20 is applied to the exposed portion 18 of the
tube 12 via air atomizing as the tube 12 is rotated. The coating 20
has a formulation of approximately 75 weight % conductive ink, 1.75
weight % polyurethane, and 23.25 weight % dimethyacetamide. The
adhesive coating 20 is applied to the exposed portion 18 of the
tube 12 via a precision viscous spray system which is controlled by
a high pressure micro-atomization microprocessor 22. (See FIG. 2.)
The coating 20 may be approximately 0.0005 inches to approximately
0.0010 inches thick. The coating 20 is then baked onto the catheter
tube 12 at a temperature of approximately 240.degree. F. The curing
process may take place within a microprocessor controlled curing
oven 24. (See FIG. 3.) The exposed surface 18 is now a cured
conductive adhesive band or surface 20a.
[0023] The catheter tube 12 is then removed from the oven 24 and
the masking tape is removed from the length 14 of the catheter tube
12. (Alternatively, the masking tape may be removed prior to the
curing step.) The catheter tube 12 is placed into another computer
automated process machine 26 which may be a microprocessor
controlled X-Y-Z Servo Motor Driver Linear Slide System. The
machine 26 has a grooving tool 28 and a coating removal tool 30.
The grooving tool 28 is designed to place radial indents or grooves
into the coated surface 20a. The removal tool 30 is designed to
scratch or cut the conductive material from an area within each of
the indented areas with a tolerance of approximately plus or minus
0.1 mm. Both grooving and removing operations take place as the
tube 12 is rotated. (See FIG. 4.) The purpose of removing the
coating at designated areas is to break the conduction between the
electrodes. For example, FIG. 5 illustrates the coated portion 20a
of the catheter tube 12 after the grooving tool 28 and removal tool
30 have been applied thereto. That is, three electrodes 32, 34, and
36 are shown which are separated from each other by four indented
areas. Within each of the indented areas is an area 38, 40, 42, and
44 that is coated and an area 46, 48, 50, and 52 where the coating
has been removed. It should be realized that three electrodes with
four indented areas have been shown by way of example only and that
any desired number of electrodes separated by indented areas may be
formed.
[0024] After the catheter tube 12 has removed from the machine 26,
portholes 54, 56, 58, and 60 are punched within each coated
indented area 38, 40, 42, and 44, respectively. (See FIG. 6.)
Magnetic wires 62, 64, 66, and 68 are then inserted through the
tube 12 so that each wire extends through a different porthole. For
example, wires 62, 64, 66, and 68 extend through portholes 54, 56,
58, and 60, respectively. The wires 54, 56, 58, and 60 are then
wrapped around their respective indented conductive areas 38, 40,
42, and 44. (See FIG. 7.) Because the wires are placed within the
indented areas, the outer surface of the catheter tube 12 will not
have intermittent bulges. That is, the entire outer surface will be
uniform. Each of the wires may be covered with a plastic material
or the like so that the wires remain electrically isolated from
each other as they run through the tube. The plastic material may
be removed from the ends of the wires protruding from the portholes
and wrapped around the conductive areas so as to be in contact with
the conductive areas.
[0025] A small amount of a conductive adhesive coating 70, such as
formulated silver paint, is then placed around the coiled magnetic
wires 62, 64, 66, and 68 via automated fluid dispensing equipment.
This permits the magnetic wires 62, 64, 66, and 68 to be in
intimate contact with their respective indented coated areas. (See
FIG. 8.) Finally, the entire indented area, that is, the coiled
wire and the area where the coating was removed, is then filled in
radially with a self-leveling UV cured, nontransparent, polymeric
adhesive 72 via EFD equipment. This adhesive insulates the
electrodes and hides all underlying markings and wiring to give the
catheter tube a finished, overall neat and uniform appearance. (See
FIG. 9.) The present invention provides several important
advantages over the prior art. For example, the coating of the
present invention is extremely flexible and possesses flexibility
equal to or greater than the polymer substrate. Also, the coating
is highly conductive, attaining its conductive properties from
silver suspended in a polymer solution. Further, the coating is
able to adhere to the most common polymers used in the
electrophysiology industry without any alteration of the coating's
chemical formulation.
[0026] The coating of the present invention dries quickly at a
slightly elevated temperature without affecting the integrity of
the polymer substrate. Animal studies have shown that the coating
is able to withstand indwelling times of up to ten hours in the
bloodstream without coating or conductive degradation. Other
laboratory tests have shown that the coating can maintain its
integrity after being immersed in a saline bath at 37.degree. C.
for 72 hours. The coating has also been proven to be biocompatible
and can be sterilized without any complications. Electrode shock
tests have also been performed where the coating was shocked with
50-Joule bursts over 35 times without any apparent damage to the
flexible electrodes. The coating of the present invention has a
higher conductivity than the prior art materials and does not
affect the flexibility of the catheter.
[0027] The present invention may be embodied in other specific
forms without departing from the spirit or essential attributes
thereof and accordingly reference should be made to the appended
claims rather than to the foregoing specification as indicating the
scope of the invention.
* * * * *