U.S. patent application number 11/818021 was filed with the patent office on 2008-12-18 for hardened polymeric lumen surfaces.
Invention is credited to Jan Weber.
Application Number | 20080312639 11/818021 |
Document ID | / |
Family ID | 39731555 |
Filed Date | 2008-12-18 |
United States Patent
Application |
20080312639 |
Kind Code |
A1 |
Weber; Jan |
December 18, 2008 |
Hardened polymeric lumen surfaces
Abstract
Apparatuses, systems, and methods for surface modification of
catheters. The surface modification can be localized to a lumen
surface of the catheter. The surface modification to the lumen
surface extends radially into the catheter body a predetermined
distance to provide a hardened zone having a hardness that is
greater than a hardness of an exterior surface of the catheter
body.
Inventors: |
Weber; Jan; (Maastricht,
NL) |
Correspondence
Address: |
Brooks & Cameron, PLLC
Suite 500, 1221 Nicollet Avenue
Minneapolis
MN
55403
US
|
Family ID: |
39731555 |
Appl. No.: |
11/818021 |
Filed: |
June 13, 2007 |
Current U.S.
Class: |
604/524 |
Current CPC
Class: |
A61M 2025/0062 20130101;
A61L 29/14 20130101; A61M 25/0045 20130101; A61L 29/04 20130101;
A61M 25/0054 20130101; A61L 2400/18 20130101; A61M 25/0023
20130101; A61M 25/0009 20130101 |
Class at
Publication: |
604/524 |
International
Class: |
A61M 25/00 20060101
A61M025/00 |
Claims
1. A catheter, comprising: a polymer elongate catheter body having
an exterior surface that extends from a first end to a second end,
and a lumen surface defining a lumen and a hardened zone that
extends into the polymer elongate catheter body, the hardened zone
having a hardness that is greater than a hardness of the exterior
surface.
2. The catheter of claim 1, where the hardened zone extends into
the polymer elongate catheter body from the lumen surface a
predetermined distance of 100 to 200 nanometers.
3. The catheter of claim 1, where the hardened zone has a uniform
hardness value.
4. The catheter of claim 1, where the hardened zone has a hardness
value that decreases in value from the lumen surface.
5. The catheter of claim 1, where the lumen surface is a carbonized
region of the polymer elongate catheter body.
6. The catheter of claim 1, where the hardened zone of the lumen
surface is a continuous surface.
7. The catheter of claim 1, where the hardened zone of the lumen
surface has a discontinuous surface with a predefined pattern.
8. A method of modifying a lumen surface of a polymer elongate
catheter body, comprising: generating a plasma of ions inside a
lumen of the polymer elongate catheter body from a first pair of
electrodes positioned outside the polymer elongate catheter body;
and driving the ions of the plasma into the lumen surface of the
polymer elongate catheter body with a second pair of electrodes
positioned outside the polymer elongate catheter body.
9. The method of claim 8, where driving the ions of plasma into the
lumen surface includes forming a hardened zone that extends into
the polymer elongate catheter body.
10. The method of claim 9, including transitioning the hardened
zone to a non-hardened zone of the polymer elongate catheter
body.
11. The method of claim 9, including controlling a depth of the
hardened zone to maintain bulk mechanical properties of the polymer
elongate catheter body.
12. The method of claim 8, where driving the ions of the plasma
includes alternating a negative and a positive voltage across the
second pair of electrodes at a predetermined frequency.
13. The method of claim 8, including rotating the first pair and
second pair of electrodes relative the polymer elongate catheter
body.
14. A method of forming a catheter, comprising: depositing a first
polymer material on a mandrel; forming a hardened zone in at least
a portion of the first polymer material on the mandrel; depositing
a second polymer material over the hardened zone to form the
catheter; and removing the mandrel from the catheter.
15. The method of claim 14, where forming the hardened zone
includes exposing the first polymer material to ions of a plasma to
carbonize the first polymer material.
16. The method of claim 15, where exposing the first polymer
material to ions of the plasma carbonizes all of the first polymer
material to form the hardened zone.
17. The method of claim 15, where exposing the first polymer
material to ions of the plasma carbonizes a portion of the first
polymer material on the mandrel to form the hardened zone.
18. The method of claim 17, including dissolving the first polymer
material to expose the carbonized layer of the hardened zone and
release the mandrel from the catheter.
19. The method of claim 14, where depositing a first polymer
material on a mandrel includes forming a non-uniform pattern of the
first polymer material; and dissolving the first polymer material
to expose the hardened zone having the non-uniform pattern.
20. The method of claim 14, where removing the mandrel from the
catheter include axially stretching the mandrel to separate the
mandrel from the catheter.
Description
TECHNICAL FIELD
[0001] The present disclosure relates generally to catheters, and
more particularly to catheters having modified surfaces.
BACKGROUND
[0002] Friction encountered between wires and catheter lumen
surfaces or between catheters and the inside of the lumen of
guiding catheters provides a significant hurdle in the ability to
smoothly steer and rotate the wires and/or catheters inside of the
human body. A suitable approach to address this problem is
needed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] FIG. 1 illustrates an embodiment of a catheter having a
lumen surface with a hardened zone according to the present
disclosure.
[0004] FIG. 2 illustrates a cross sectional view of the catheter of
FIG. 1 taken along lines 2-2 according to one embodiment of the
present disclosure.
[0005] FIG. 3 illustrates an apparatus for the surface modification
of a lumen surface of a catheter according to one embodiment of the
present disclosure.
[0006] FIG. 4 illustrates a cross sectional view of the apparatus
and the catheter of FIG. 3 taken along lines 4-4 according to the
present disclosure.
[0007] FIGS. 5A-5D illustrate the formation of a catheter having a
hardened zone according to one embodiment of the present
disclosure.
[0008] FIGS. 6A-6D illustrate the formation of a catheter having a
hardened zone according to one embodiment of the present
disclosure.
[0009] FIGS. 7A-7D illustrate the formation of a catheter having a
hardened zone according to one embodiment of the present
disclosure.
[0010] FIGS. 8A-8D illustrate the formation of a catheter having a
hardened zone according to one embodiment of the present
disclosure.
DETAILED DESCRIPTION
[0011] Embodiments of the present disclosure are directed to
apparatuses, systems, and methods for surface modification of
catheters. For the various embodiments, the surface modification
can be localized to a lumen surface of the catheter. The surface
modification to the lumen surface extends radially into the
catheter body a predetermined distance to provide a hardened
zone.
[0012] As used herein, a "hardened zone" includes a region of the
material forming at least a portion of the catheter that extends
from the lumen surface toward an exterior surface of the catheter,
where the material in the region of the hardened zone has undergone
at least a partial modification from energy delivered by ions
driven into the elongate body according to the methods of the
present disclosure. For the various embodiments, the hardened zone
can provide either a non-discrete or discrete layer resulting from
a change to the material forming the catheter.
[0013] For the various embodiments, the catheter includes a
polymeric elongate body that is subjected to at least a partial
modification by an ion treatment discussed herein. The ion
treatment of the present disclosure can result in the formation of
a high level of macromolecule defects in a thin surface layer of
the catheter material to form the hardened zone. For the various
embodiments, the macromolecule defects cause structure
transformations of the polymer chains through chemical reactions of
free radicals formed by the ions, which can cause the formation of
the hardened zone.
[0014] As used herein, a "modification" of the polymer chains
forming the polymeric elongate body includes disrupting and
recombining carbon-carbon bonds of the polymeric material to form
structures ranging from amorphous carbon, fully carbonized or
graphitized, partially carbonized to diamond like structures.
[0015] In addition, the thickness of the hardened zone can
correspond to the distribution of defects which are determined by
the energy and the kind of ions and/or the kind of polymer used in
forming the polymer elongate body. The depth of the modification
can be from several tens of nanometers to hundreds of nanometers,
as will be discussed herein.
[0016] As used herein, the terms "a," "an," "one or more," and "at
least one" are used interchangeably. In addition, it is recognized
that the surface modification of the present disclosure is not
limited to lumen surfaces and can be used on other areas and/or
regions of a catheter in addition to the lumen surface.
[0017] Unless otherwise indicated, all numbers expressing
quantities of ingredients, processing conditions, and so forth used
in the disclosure and claims are to be understood as being modified
in all instances by the term "about." Accordingly, unless indicated
to the contrary, the numerical parameters set forth in the
following specification and attached claims are approximations that
may vary depending upon the desired properties sought to be
obtained by the present disclosure. At the very least, each
numerical parameter should at least be construed in light of the
number of reported significant digits and by applying ordinary
rounding techniques.
[0018] For the various embodiments, the hardened zone formed at and
extending from the lumen surface results in a surface having a
material hardness that is greater than the material hardness of
other polymer regions of the catheter body. For the various
embodiments, the hardened zone can be formed from the polymeric
material that forms (i.e., constitutes) the unmodified catheter
(i.e., the catheter before surface modification according to the
present disclosure). In other words, the hardened zone is formed in
the polymeric material forming the catheter body, as apposed to
being applied to polymeric material of the catheter body.
[0019] For the various embodiments, the hardened zone of the
present disclosure provides for reduced contact frictional forces
between the lumen surface and an item being moved relative thereto
(e.g., through the lumen) as compared to an unmodified catheter.
Such items can include, but are not limited to guidewires, balloon
catheters, enclosed self-expanding stents, surgical instruments
guided through endoscopic catheters or urological catheters (such
as kidney stone retrieval baskets), and/or additional catheters. In
addition, the presence of the hardened zone does not significantly,
if at all, affect the bulk physical properties of the catheter as
compared to an unmodified catheter. In other words, a catheter
having the hardened zone according to the present disclosure
display essentially the same bulk mechanical properties (e.g.,
stiffness, elongation at breaking, modulus of elasticity, tensile
strength, stress-strain response, flexibility, etc.) as an
identical catheters not having the hardened zone of the present
disclosure. In addition, the hardened zone also resists sloughing
or flaking of the polymeric material that forms the hardened
zone.
[0020] The figures herein follow a numbering convention in which
the first digit or digits correspond to the drawing figure number
and the remaining digits identify an element or component in the
drawing. Similar elements or components between different figures
may be identified by the use of similar digits. For example, 110
may reference element "10" in FIG. 1, and a similar element may be
referenced as 210 in FIG. 2. As will be appreciated, elements shown
in the various embodiments herein can be added, exchanged, and/or
eliminated so as to provide any number of additional embodiments of
the present disclosure. In addition, as will be appreciated the
proportion and the relative scale of the elements provided in the
figures are intended to illustrate the embodiments of the present
invention, and should not be taken in a limiting sense.
[0021] FIG. 1 provides an embodiment of a catheter 100 according to
the present disclosure. The catheter 100 includes a polymer
elongate catheter body 102 having an exterior surface 104 that
extends from a first end 106 to a second end 108. As illustrated,
the catheter 100 further includes an inflatable balloon 110
positioned around the catheter 100. An inflation lumen 112 extends
from the first end 106 of the polymer elongate catheter body 102 to
be in fluid communication with an interior chamber of the
inflatable balloon 110 to allow the balloon 110 to be inflated and
deflated.
[0022] The catheter 100 further includes a lumen surface 114 that
defines a lumen 116. In one embodiment, the lumen 116 extends from
the first end 106 to the second end 108. Alternatively, the lumen
116 can extend from the first end 106 to a location between the
first and second ends 106 and 108.
[0023] The catheter 100 further includes a hardened zone 118
according to the present disclosure. For the present embodiments,
the hardened zone 118 originates from the polymer structure forming
the polymer elongate catheter body 102 through the modification
processes described herein. In one embodiment, the hardened zone
118 of the lumen surface 114 can be a continuous surface of the
modified polymeric material. Alternatively, the hardened zone can
have a discontinuous surface with a predefined pattern, as will be
discussed more fully herein.
[0024] In one embodiment, the hardened zone 118 extends radially
into the polymer elongate catheter body 102 from the lumen surface
114 to a predetermined depth. For the various embodiments, the
predetermined depth of the hardened zone 118 can be from about 2
nanometers to about 400 nanometers. Alternatively, the thickness or
depth of the hardened zone 118 can be from about 20 nanometers to
about 200 nanometers, or from about 100 nanometers to about 200
nanometers. Alternatively, expressed as a percentage, the
predetermined depth can have a value of 0.05 percent (%) through 10
percent (%) of the average wall thickness of the polymer elongate
catheter body 102.
[0025] For the various embodiments, the hardened zone 118 can have
a material hardness value ranging from 1 Gpa (e.g., when formed
from polymers having a high ratio of sp.sup.2/sp.sup.3 hybrid
bonds) to 40 Gpa (e.g., when formed from polymers having mainly
sp.sup.3 bonds). Measurements of the hardened zone 118 can be made
using a Nano-Hardness Tester, for example from CSM Instruments Inc.
(Needham, Mass., USA). The Nano-Hardness Tester is specially suited
to load and penetration depth measurements at nanometer length
scales. The Nano-Hardness Tester(s) can also be used in the
analysis of organic and inorganic soft and hard coatings.
[0026] For the various embodiments, the material hardness of the
hardened zone can be uniform through its predetermined depth.
Alternatively, the hardened zone 118 can have a material hardness
value (e.g., 5.30 Gpa) that changes (e.g., decreases) in value from
the lumen surface 114 through its predetermined depth. In addition,
the thickness of the hardened zone 118 has little to no measurable
effect on the bulk mechanical properties (e.g., stiffness,
elongation at breaking, modulus of elasticity, tensile strength,
stress-strain response, flexibility, etc.) of the polymer elongate
catheter body 102.
[0027] FIG. 2 provides a cross-sectional view of the catheter 100
taken along the lines 2-2 in FIG. 1. According to the embodiment
illustrated in FIG. 2, the hardened zone 218 extends into the
elongate body 202 from the lumen surface 214. For the various
embodiments, the hardened zone 218 can gradually transition from,
for example, a carbonized region at the lumen surface 214 through a
partially carbonized region of the polymeric material to a deeper
unaffected polymeric material of the polymer elongate catheter body
202.
[0028] In one embodiment, variation in the depth of the hardened
zone 218 can be attributed to the surface modification process of
the present disclosure in which ions are driven into the lumen
surface 214 of the polymer elongate catheter body 202. Depending on
the energy of the ions being driven into the lumen surface 214, the
polymeric bonds of the polymer elongate catheter body 202 are
disrupted and recombine as carbon-carbon structures, ranging from
amorphous carbon to diamond like structures, up to a depth of
several tens or hundreds of nanometers, as discussed herein. The
resulting hardened zone 218 has a surface with a material hardness
that is greater than both a hardness of the lumen surface before
the surface modification and the exterior surface 204 of the
polymer elongate catheter body 202.
[0029] The carbonization and oxidation processes discussed herein
can be observed in a variety of polymers. Suitable polymer include,
block co-polymers of polyamide and polyether sold under the trade
designator Pebax, nylons, polyurethanes, polyamides, polyethylene,
silicone, latex, polyethylene terephthalate or other polyesters,
polyvinylchloride, etc. More generally, polymers having a high
content of carbon-carbon bonds are also suitable.
[0030] Referring back to FIG. 1, the lumen 116 is configured to
receive and pass a guidewire for guiding and positioning the
catheter 100 in the vasculature. In one embodiment, the hardened
zone 118 allows for a reduced coefficient of friction (e.g., static
and kinetic fiction) between the lumen surface 114 and the
guidewire as compared to an unmodified lumen surface of the same
polymer elongate body under the same conditions (e.g., temperature,
relative speed of the guidewire and catheter, the contact geometry
the guidewire and catheter experience).
[0031] As will be appreciated, the hardened zone as discussed
herein can be created in a number of different types of catheters.
One example is the balloon catheter 100 illustrated in FIG. 1.
Other examples include, but are not limited to, coronary guide
catheters that can be used to pass guidewires and/or balloon
catheters, including balloon catheters with a stent mounted
thereto. An addition example includes a catheter or sheath used in
holding, moving and/or delivering a self-expanding stent to an
implant location in the body.
[0032] Other applications for the present disclosure can include
surface modification of lumens in cardiac leads, such as pacing
leads and/or defibrillation leads. In addition, surface
modification according to the present disclosure can be used with a
lumen surface of a medical device that has a small inner diameter
(e.g., I.D. of 5 mm or less), which would benefit from a reduction
in a coefficient of friction between the lumen of the medical
device and one or more other structures that come in contact with
the lumen.
[0033] FIG. 3 provides an illustration of an apparatus 330 for the
surface modification of the catheter 300 as discussed herein. In
one embodiment, the apparatus 330 can modify the catheter 300 by
driving ions into the catheter 300. One example of driving ions
into the catheter 300 can be through a Plasma Ion Immersion
Implantation (PIII), in which high energetic ions (5-40 keV) are
driven into the polymer surface of the catheter 300. As discussed
herein, this surface modification produces the hardened zone 318 of
the present disclosure in the catheter 300.
[0034] As illustrated, the apparatus 330 includes a first pair of
plasma electrodes 332 and a second pair of implanting electrodes
334 positioned outside, around and adjacent to the exterior surface
304 of the polymer elongate body 302. The apparatus 330 further
includes a housing 336 positioned around the plasma electrodes 332
and the implanting electrodes 334. In one embodiment, the housing
336 is formed of an electrically insulating material to better
direct energy from the electrodes 332 and 334 across the elongate
body 302 of the catheter 300. Examples of such materials include,
but are not limited to, glass and polytetrafluoroethylene (PTFE).
Other electrically insulating materials are known and could be used
for the housing 336.
[0035] For the various embodiments, the plasma generating
electrodes 332 can be used to create a plasma 340 of ions inside
the lumen 316 of the catheter 300. In one embodiment, the plasma
electrodes 332 can include a cathode 342 and an anode 344
positioned in an opposing configuration across the catheter 300.
For the various embodiments, the catheter 300 can be feed through
the apparatus 330 past the electrodes 332, where the electrodes 332
and the housing 336 are in close proximity to the exterior surface
304 of the elongate body 302 so as to prevent the formation of
plasma outside the lumen 316.
[0036] For the various embodiments, the plasma electrodes 332 can
be used to provide RF energy to a plasma gas being streamed through
the lumen 316 to generate the plasma 340 inside of the lumen 316.
In one embodiment, the plasma gas can include one or more of
nitrogen (N.sub.2), argon (Ar), xenon (Xe), helium (He), oxygen
(O.sub.2) and/or combinations thereof. For the various embodiments,
the plasma gas can be streamed through the lumen 316 at a pressure
in the range of 10.sup.-3 Pa through 10.sup.-1 Pa.
[0037] To generate the plasma 340, the plasma electrodes 332 can be
operatively connected to a radiofrequency generator 350. For the
various embodiments, the radiofrequency generator 350 can provide
power at a desired frequency to the electrodes 332 to generate the
plasma 340. For the various embodiments, the radiofrequency
generator 350 can apply RF energy pulses at a predetermined
frequency (i.e., a pulse repetition frequency) of 0.2 Hz to 200 Hz.
In one embodiment, pulsing the RF energy helps to prevent
overheating of the polymer elongate body 302 of the catheter 300
during the surface modification techniques in producing the
hardened zone. In addition, the radiofrequency generator 350 can
deliver RF energy through the electrodes 332 at peak voltages in
the range of 5 to 40 keV. Specific examples of such peak voltages
include, but are not limited to, 5, 10, 20 and 30 keV.
[0038] The ions from the plasma 340 can then be driven into the
lumen surface 314 using the second pair of implanting electrodes
334. For example, the second pair of implanting electrodes 334 can
be used to accelerate and drive the ions from the plasma 340 into
the wall of the lumen surface 314 to form the hardened zone 318
described herein.
[0039] In one embodiment, the implanting electrodes 334 can be used
to deliver alternating negative and positive voltage pulses at a
voltage of 20 to 40 keV across the implanting electrodes 334 at the
predetermined frequency to accelerate and drive the ions from the
plasma 340 into the wall of the lumen surface 314. For the various
embodiments, the predetermined frequency can have a value of 100 to
600 Hz. For the various embodiments, this allows for doses of ions
delivered from the plasma 340 to the lumen surface 314 to be from
5.times.10.sup.14 through 10.sup.17 ions/cm.sup.2, where doses of
10.sup.16 ions/cm.sup.2 or higher are also suitable.
[0040] The operating parameters of the apparatus 330 discussed
herein can be used to form different configurations of the hardened
zone 318 in the polymer elongate body 302. For example, the
operating parameters can be used to create the hardened zone 318
that gradually transitions from one or more of an amorphous carbon,
fully carbonized or graphitized, partially carbonized to diamond
like surface to a non-hardened zone in the polymer elongate
catheter body 302. In addition, the operating parameters can be
used to control the depth, or thickness, of the hardened zone 318,
as discussed herein, to maintain bulk mechanical properties of the
polymer elongate catheter body 302.
[0041] For the various embodiments, the relative size and position
of the plasma electrodes 332 and the implanting electrodes 334 can
be configured to better maintain the stability of the plasma 340
inside the lumen 316 of the polymer elongate catheter body 302. In
some situations the implanting electrodes 334 can disrupt the
plasma 340 as they drive the ions into the elongate body 302. In
one embodiment, the plasma electrodes 332 can extend past the
implanting electrodes 334 upstream relative the direction of plasma
gas flow to better maintain and supply the plasma 340 to the region
of the implanting electrodes 334. For the various embodiments, the
plasma electrodes 332 can be at least twice as long as the
implanting electrodes 334 as measured in the direction of the
longitudinal axis of the elongate body 302.
[0042] In addition embodiment, the supply of the plasma 340 formed
with the plasma electrodes 332 can also be dependent upon both the
flow rate of the plasma gas and the pulse frequency of the RF
energy used to form the plasma 340. For example, the flow rate of
the plasma gas and the pulse frequency of RF energy delivered from
the plasma electrodes 340 can be adjusted so as to ensure that
enough plasma gas is supplied between pulses to allow for more
plasma 340 to be formed. As a result, the faster the pulse
frequency of the RF energy, the faster the flow rate of the plasma
gas may need to be.
[0043] In an additional embodiment, to better ensure the surface
modification treatment of the present disclosure treats the entire
lumen surface 314 of the elongate body 302, one or both of the
electrodes 332 and 334 and/or the catheter 300 can be rotated
relative each other around the longitudinal axis of the catheter
300. Also, to treat longer sections of catheters 300, the elongate
body 302 can be feed past the electrodes 332 and 334 via a
reel-to-reel system.
[0044] FIG. 4 provides a cross-sectional view of the apparatus 330
taken along the lines 4-4 in FIG. 3. As illustrated, the electrodes
432 and 434 and the housing 436 can rotate relative the elongate
body 402 of the catheter 400, or visa versa, to better ensure the
ions being driven by the implanting electrode 434 are exposure
around the lumen surface 414. In an additional embodiment, both the
apparatus 430 and the elongate body 402 can be rotated in opposite
directions simultaneously.
[0045] FIGS. 5A-5D provide an additional embodiment of the catheter
500 according to the present disclosure. As discussed herein, the
catheter 500 illustrates an embodiment in which the hardened zone
518 is formed as a discrete layer relative the remaining portions
of the catheter 500. In one embodiment, the hardened layer 518 can
be formed having a uniform hardness value through the thickness of
the hardened layer 518.
[0046] For the various embodiments, a layer 562 of a first polymer
material can be deposited on a mandrel 560, as illustrated in FIG.
5A. For the various embodiments, the mandrel 560 can be an
electrically conductive, flexible, ductile, metal or a metal alloy.
Examples of suitable materials for the mandrel 560 include, but are
not limited to, copper, brass, zinc, and PTFE coated soft metallic
alloys.
[0047] In one embodiment, the first polymer material can be one or
more of the polymers discussed herein. As will be appreciated,
depositing the first polymer material on the mandrel 560 can be
accomplished by a number of different coating techniques. Such
techniques include, but are not limited to, spray coating,
ultrasonic mist coating, dip coating, electrostatic coating,
over-extrusion techniques and/or printing or patterning the polymer
layer 562 on the mandrel 560. Other coating techniques are also
possible.
[0048] In one embodiment, the resulting polymer layer 562 can have
a thickness of about 2 nanometers to about 400 nanometers, from
about 20 nanometers to about 200 nanometers, or from about 100
nanometers to about 200 nanometers. Other thicknesses are also
possible.
[0049] FIG. 5B provides an illustration of the mandrel 560 with its
polymer layer 562 being fed through the apparatus 530 to form the
hardened zone 518 in at least a portion of the first polymer
material. As discussed herein, the apparatus 530 includes the
housing 536, the plasma electrodes 532 for generating the plasma
540 and the implanting electrodes 534 for driving the ions into the
polymer layer 562.
[0050] For the present embodiment, the mandrel 560 can be formed of
an electrically conductive material to allow the mandrel 560 to be
used as a pole (e.g., a cathode) in delivering alternating negative
and positive voltage pulses, as discussed herein, for driving the
ions into the polymer layer 562. The result can be the formation of
the hardened zone 518 from the polymer layer 562. For the various
embodiments, the entire polymer layer 562 can be formed into the
hardened zone 518, as discussed here. Alternatively, less than the
entire polymer layer 562 can be formed into the hardened zone 518,
as will be more fully discussed herein.
[0051] For the various embodiments, the plasma gas, as discussed
herein, used in forming the plasma 540 can be supplied between the
electrodes 532, 534 and the polymer layer 562. For the various
embodiments, the flow rate of the plasma gas can be dependent upon
the frequency of the RF pulses delivered from the plasma electrodes
532 and the desire to maintain a stable plasma 540.
[0052] As discussed herein, the apparatus 530 and/or the mandrel
560 with the polymer layer can rotate relative the other or
relative each other. In addition, the electrodes 532 and 534 can
have the same proportional and configurational relationship as
discussed herein (e.g., the plasma electrodes 532 being longer than
the implanting electrodes 534).
[0053] FIG. 5C next illustrates the hardened layer 518 formed over
the mandrel 560 being coated with one or more layers of a second
polymer material to form the catheter 500. In one embodiment, the
second polymer material can be the same type of polymer used to
form the polymer layer 562 and/or a different polymer to form the
polymer elongate body 502 of the catheter 500. The polymer(s) used
in the coating process can include those provided herein.
Alternatively, other polymer and/or non-polymer materials can be
used in coating the hardened zone 518 formed on the mandrel
560.
[0054] In one embodiment, the coating process can be applied
through an over-extrusion process. Alternatively, the coating
process can be a can be a dip coating technique. Other coating
processes discussed herein are also possible. The mandrel 560 can
then be removed from the catheter 500 by axially stretching the
mandrel 560 so as to reduce its diameter and allow it to be
separated and removed from the catheter 500.
[0055] FIG. 6A-6D provides an additional embodiment of the catheter
600 according to the present disclosure. As discussed herein, the
catheter 600 illustrates an embodiment in which the hardened zone
618 is formed as a discrete layer relative the remaining portions
of the catheter 600.
[0056] As illustrated in FIG. 6A, the mandrel 660 can be coated
with the layer 662 of the first polymer material, as discussed
herein, by one or more of the coating techniques discussed herein.
The resulting polymer layer 662 can have a thickness sufficient to
allow a portion of the polymer layer 662 to be converted into the
hardened zone 618 while leaving at least a portion of the polymer
layer 662 between the hardened zone 618 and the mandrel 660.
Examples of suitable thicknesses include, but are not limited to,
about 300 nanometers to about 600 nanometers.
[0057] FIG. 6B provides an illustration of the mandrel 660 with its
polymer layer 662 after being fed through the apparatus, as
discussed herein, to transform at least a portion of the polymer
layer 662 into the hardened zone 618. For the present embodiment,
the ion and implant energy used with the plasma and implanting
electrodes can be selected to be such that the portion of the
polymer layer 662 from the exterior surface toward the mandrel 660
is transformed (e.g., carbonized) into the hardened layer 618. As
illustrated in FIG. 6B, the result is a region of the polymer layer
662 positioned between the hardened layer 618 and the mandrel
660.
[0058] FIG. 6C next illustrates the hardened layer 618 being coated
with one or more layers of the same polymer used to form the
polymer layer 662 and/or a different polymer to form the polymer
elongate body 602 of the catheter 600. The polymer(s) used in the
coating process can include those provided herein. Alternatively,
other polymer and/or non-polymer materials can be used in coating
the hardened zone 618. In one embodiment, the coating process can
be applied through one or more processes discussed herein.
[0059] A solvent can then be used to dissolve the first polymer
material of the layer 662 to both expose the hardened zone 618 and
release the mandrel 660 from the catheter 600, as illustrated in
FIG. 6D. Selection of a suitable solvent will depend upon the
polymer(s) used in forming the polymer layer 662.
[0060] FIGS. 7A-7D provide a further illustration of the catheter
700 according to the present disclosure. As discussed herein, the
catheter 700 illustrates an embodiment in which the hardened zone
718 is formed as a non-uniform continuous layer. As illustrated in
FIG. 7A, a layer 762 of a first polymer material can be deposited,
as discussed herein, on the mandrel 760 as a predefined pattern
766. In one embodiment, the predefined pattern 766 can be applied
using one or more of a spray coating techniques, including ink-jet
coating and/or printing techniques.
[0061] For the various embodiments, the predefined pattern 766
includes a layer having different thicknesses of the layer 762 at
different portions along the mandrel 760. For example, in one
embodiment a series of additional "dots" of the first polymer can
be added to the top of the layer 762 to form the predefined pattern
766. Other shapes, patterns and/or configurations besides dots can
be used with and/or for the predefined pattern 766.
[0062] The layer 762 with its predefined pattern 766 can then be
fed through the apparatus, as discussed herein, to transform at
least a portion of the polymer layer 762 into the hardened zone
718. In one embodiment, the ion and implant energy used with the
plasma and implanting electrodes can be selected so that only the
portion of the polymer layer 762 from the exterior surface toward
the mandrel 760 is transformed (e.g., carbonized) into the hardened
layer 718. As illustrated in FIG. 7B, the result is a region of the
polymer layer 762 positioned between the hardened layer 718 and the
mandrel 760.
[0063] In addition, the apparatus 733 transforms a uniform
thickness of the polymer layer 762 into the hardened zone 718. In
one embodiment, transforming the uniform thickness of the polymer
layer 762 into the hardened zone 718 forms pockets or divots 770 in
the hardened layer 718 that mirror the predefined pattern 766. As a
result, the hardened layer 718 has a pattern that is a scaled
negative cast of the predefined pattern 766 applied to the polymer
layer 762.
[0064] FIG. 7C next illustrates the hardened layer 718 being coated
with one or more layers of the same polymer used to form the
polymer layer 762 and/or a different polymer to form the polymer
elongate body 702 of the catheter 700. The polymer(s) used in the
coating process can include those provided herein. Alternatively,
other polymer and/or non-polymer materials can be used in coating
the hardened zone 718. In one embodiment, the coating process can
be applied through one or more processes discussed herein.
[0065] A solvent can then be used to dissolve the first polymer
material of the layer 762 to both expose the hardened zone 718 with
its predefined pattern and release the mandrel 760 from the
catheter 700, as illustrated in FIG. 7D. Selection of a suitable
solvent will depend upon the polymer(s) used in forming the polymer
layer 762.
[0066] FIGS. 8A-8D provide a further illustration of the catheter
800 according to the present disclosure. As discussed herein, the
catheter 800 illustrates an embodiment in which the hardened zone
818 is formed as a non-uniform discontinuous layer. As illustrated
in FIG. 8A, a predefined pattern 866 of the first polymer can be
sprayed or printed onto the mandrel 860. Examples of the predefined
pattern 866 include, but are not limited to dots, lines,
geometries, curves, and random patterns, among others. Use of more
than one pattern is possible.
[0067] The mandrel 860 with the predefined pattern 866 of the first
polymer can then be fed through the apparatus, as discussed herein,
to transform the predefined pattern 866 of the first polymer into
the hardened zone 818, as illustrated in FIG. 8B. The mandrel 860
with the hardened zone 818 with the predefined pattern 866 can then
be being coated with one or more layers of the same polymer used to
form the polymer layer 862 and/or a different polymer to form a
sacrificial polymer layer 884 between the predefined pattern(s) 880
of the hardened zone 818, as illustrated in FIG. 8C.
[0068] The mandrel 860 with the hardened zone 818 in the predefined
pattern 866 and the sacrificial polymer 884 can then be coated with
the second polymer to form the polymer elongate body 802 of the
catheter 800. The polymer(s) used in the coating process can
include those provided herein. Alternatively, other polymer and/or
non-polymer materials can be used in coating the hardened zone 818.
In one embodiment, the coating process can be applied through one
or more processes discussed herein.
[0069] A solvent can then be used to dissolve the sacrificial
polymer 884 material of the layer 862 to both expose the predefined
pattern 866 of the hardened zone 818 extending from the lumen
surface of the polymer elongate body 802 and to release the mandrel
860 from the catheter 800, as illustrated in FIG. 8D. Selection of
a suitable solvent will depend upon the polymer(s) used in forming
the sacrificial polymer layer.
[0070] While the present invention has been shown and described in
detail above, it will be clear to the person skilled in the art
that changes and modifications may be made without departing from
the spirit and scope of the invention. As such, that which is set
forth in the foregoing description and accompanying drawings is
offered by way of illustration only and not as a limitation. The
actual scope of the invention is intended to be defined by the
following claims, along with the full range of equivalents to which
such claims are entitled. In addition, one of ordinary skill in the
art will appreciate upon reading and understanding this disclosure
that other variations for the invention described herein can be
included within the scope of the present invention.
[0071] In the foregoing Detailed Description, various features are
grouped together in several embodiments for the purpose of
streamlining the disclosure. This method of disclosure is not to be
interpreted as reflecting an intention that the embodiments of the
invention require more features than are expressly recited in each
claim. Rather, as the following claims reflect, inventive subject
matter lies in less than all features of a single disclosed
embodiment. Thus, the following claims are hereby incorporated into
the Detailed Description, with each claim standing on its own as a
separate embodiment.
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