U.S. patent application number 11/762617 was filed with the patent office on 2007-11-01 for textured polymer coated guide wire and method of manufacture.
This patent application is currently assigned to ABBOTT CARDIOVASCULAR SYSTEMS INC.. Invention is credited to Kevin Britton, David H. Burkett, Wayne E. Cornish, Peter J. D'Aquanni, Ryan Grandfield, Edwin P. Mahieu, Mark T. Richardson, David Wrolstad.
Application Number | 20070255217 11/762617 |
Document ID | / |
Family ID | 38649232 |
Filed Date | 2007-11-01 |
United States Patent
Application |
20070255217 |
Kind Code |
A1 |
Burkett; David H. ; et
al. |
November 1, 2007 |
TEXTURED POLYMER COATED GUIDE WIRE AND METHOD OF MANUFACTURE
Abstract
A guide wire for advancing a medical device such as a catheter
through a patient's body lumen which has an elongated core with
proximal and distal core section, a flexible tubular member such as
a coil on the distal end. The wire core includes surface textures
that are translated into the overlying coating. Alternatively, the
coating has its own surface texture. The surface textures include
randomly or non-randomly spaced bumps, divots, ridges, helical
grooves, longitudinal grooves, undulations, etc.
Inventors: |
Burkett; David H.;
(Temecula, CA) ; Britton; Kevin; (Murrieta,
CA) ; Grandfield; Ryan; (Murrieta, CA) ;
D'Aquanni; Peter J.; (Murrieta, CA) ; Wrolstad;
David; (Temecula, CA) ; Mahieu; Edwin P.;
(Temecula, CA) ; Cornish; Wayne E.; (Fallbrook,
CA) ; Richardson; Mark T.; (Escondido, CA) |
Correspondence
Address: |
FULWIDER PATTON LLP
HOWARD HUGHES CENTER
6060 CENTER DRIVE, TENTH FLOOR
LOS ANGELES
CA
90045
US
|
Assignee: |
ABBOTT CARDIOVASCULAR SYSTEMS
INC.
3200 Lakeside Drive
Santa Clara
CA
95054
|
Family ID: |
38649232 |
Appl. No.: |
11/762617 |
Filed: |
June 13, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10664004 |
Sep 16, 2003 |
|
|
|
11762617 |
Jun 13, 2007 |
|
|
|
Current U.S.
Class: |
604/164.13 |
Current CPC
Class: |
A61M 2025/09108
20130101; A61M 2025/0062 20130101; B29C 48/05 20190201; A61B
17/12145 20130101; A61M 25/09 20130101; B29C 48/155 20190201; A61M
25/0043 20130101; A61M 2025/09133 20130101; B29C 48/12 20190201;
A61M 2025/006 20130101; A61F 2/95 20130101; A61F 2/958
20130101 |
Class at
Publication: |
604/164.13 |
International
Class: |
A61M 5/178 20060101
A61M005/178 |
Claims
1. An intraluminal guide wire, comprising: an elongated core having
a proximal core section and a distal core section having a distal
end, wherein at least a section of the elongated core includes
randomized and non-randomized tactile surface contours, wherein the
surface contours are spaced apart in a range of about 0.05 cm to 2
cm and have a surface-to-peak amplitude of about 0.0002 to 0.002
inch; an uninterrupted polymer coating with a generally constant
outside diameter adhering to at least a portion of the elongated
core and having a surface contour that follows the randomized and
non-randomized tactile surface contours in the elongated core; and
a flexible tubular member disposed over the distal core
section.
2. The intraluminal guide wire of claim 1, wherein the tactile
surface contours can be detected by touch of a user's finger.
3. The intraluminal guide wire of claim 1, wherein the tactile
surface contours include at least a bump.
4. The intraluminal guide wire of claim 1, wherein the tactile
surface contours include at least a divot.
5. The intraluminal guide wire of claim 1, wherein the tactile
surface contours include at least a helical pattern.
6. The intraluminal guide wire of claim 1, wherein the tactile
surface contours include at least a rib.
7. The intraluminal guide wire of claim 1, wherein the tactile
surface contours include at least an undulation.
8. The intraluminal guide wire of claim 1, wherein the tactile
surface contours include at least a longitudinal groove.
9. The intraluminal guide wire of claim 1, wherein the tactile
surface contours include ridges and dips.
10. The intraluminal guide wire of claim 1, wherein the tactile
surface contours include at least a circumferential groove.
11. The intraluminal guide wire of claim 1, wherein the polymer
coating is disposed over the flexible tubular member.
12. The intraluminal guide wire of claim 1, wherein the proximal
core section includes a high strength steel and the distal core
section includes a nickel-titanium alloy.
13. The intraluminal guide wire of claim 1, wherein the polymer
coating includes a fluoropolymer.
14. An intraluminal guide wire, comprising: an elongated core
having a proximal core section and a distal core section including
a taper transitioning to a distal end, wherein an exterior surface
of the distal core section is substantially smooth and without
interruptions; a polymer coating of generally uniform thickness
adhering to at least a portion of the distal core section with a
coating profile following a tapered profile of the elongated core,
the polymer coating having an exterior surface with at least one of
randomized and non-randomized surface contours that can be detected
by human touch; and a flexible tubular member disposed over the
distal core section.
15. The intraluminal guide wire of claim 14, wherein the surface
contours include a rib.
16. The intraluminal guide wire of claim 14, wherein the surface
contours include a helical pattern.
17. The intraluminal guide wire of claim 14, wherein the tactile
surface contours include a longitudinal groove.
18. A method for providing an intraluminal guide wire, comprising:
providing an elongated core having a proximal core section and a
distal core section having a substantially smooth exterior surface;
tapering a profile of the elongated core to transition into a
distal end; heating and extruding a polymer through a die to adhere
to at least a portion of the elongated core to create a polymer
coating; and imparting into an exterior surface of the polymer
coating at least one of randomized and non-randomized surface
contours that are independent from the profile of the elongated
core, wherein the at least one of the randomized and non-randomized
surface contours have sufficient texture to be detectable by human
touch.
19. The method of claim 18, wherein the step of imparting into an
exterior surface of the polymer coating further comprises providing
a V-block, disposing the elongated core into the V-block, aiming an
energized laser at right angle to the elongated core while
advancing and rotating elongated core past the laser.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation application of co-pending
U.S. application Ser. No. 10/664,004, filed Sep. 16, 2003, whose
entire contents is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] This present invention relates to the field of guide wires
used for advancing intravascular devices such as stent delivery
catheters, balloon dilatation catheters, and atherectomy catheters
within a body lumen. More specifically, the present invention
relates to a guide wire with a polymer coating having a textured
surface.
[0003] Conventional guide wires for angioplasty, stent delivery,
atherectomy and other vascular procedures usually comprise an
elongated core with one or more tapered sections near the distal
end thereof and a flexible body such as a helical coil or a tubular
body of polymeric material disposed about the distal portion of the
elongated core. A shapable member, which may be the distal
extremity of the elongated core or a separate shaping ribbon which
is secured to the distal extremity of the elongated core, extends
through the flexible body and is secured to the distal end of the
flexible body by soldering, brazing, or welding, which forms a
rounded distal tip. Torquing means are provided on the proximal end
of the elongated core to rotate, and thereby steer, the guide wire
while it is being advanced through a patient's vascular system.
[0004] Further details of guide wires and devices associated
therewith for various interventional procedures can be found in,
for example, U.S. Pat. No. 4,748,986 (Morrison et al.); U.S. Pat.
No. 4,538,622 (Samson et al.); U.S. Pat. No. 5,135,503 (Abrams),
U.S. Pat. No. 5,341,818 (Abrams et al.), and U.S. Pat. No.
5,345,945 (Hodgson et al.), which are hereby incorporated herein in
their entirety by reference thereto.
[0005] In a typical coronary procedure using a guide wire, a
guiding catheter having a preformed distal tip is percutaneously
introduced into a patient's peripheral artery, e.g., femoral or
brachial artery, by means of a conventional Seldinger technique and
advanced and steered therein until the distal tip of the guiding
catheter is seated in the ostium of a desired coronary artery.
[0006] There are two basic techniques for advancing a guide wire
into the desired location within the patient's coronary anatomy
through the in-place guiding catheter. The first is a preload
technique which is used primarily for over-the-wire (OTW) devices,
and the second is the bare wire technique which is used primarily
for rail type systems.
[0007] With the preload technique, a guide wire is positioned
within an inner lumen of an OTW device such as a dilatation
catheter or stent delivery catheter with the distal tip of the
guide wire just proximal to the distal tip of the catheter and then
both are advanced through the guiding catheter to the distal end
thereof. The guide wire is first advanced out of the distal end of
the guiding catheter into the patient's coronary vasculature until
the distal end of the guide wire crosses the arterial location
where the interventional procedure is to be performed, e.g., a
lesion to be dilated or a dilated region where a stent is to be
deployed. The catheter, which is slidably mounted onto the guide
wire, is advanced out of the guiding catheter into the patient's
coronary anatomy over the previously introduced guide wire until
the operative portion of the intravascular device, e.g., the
balloon of a dilatation or a stent delivery catheter, is properly
positioned across the arterial location. Once the catheter is in
position with the operative means located within the desired
arterial location, the interventional procedure is performed. The
catheter can then be removed from the patient over the guide wire.
Usually, the guide wire is left in place for a period of time after
the procedure is completed to ensure reaccess to the arterial
location if it is necessary. For example, in the event of arterial
blockage due to dissected lining collapse, a rapid exchange type
perfusion balloon catheter such as described and claimed in U.S.
Pat. No. 5,516,336 (McInnes et al.), can be advanced over the
in-place guide wire so that the balloon can be inflated to open up
the arterial passageway and allow blood to perfuse through the
distal section of the catheter to a distal location until the
dissection is reattached to the arterial wall by natural
healing.
[0008] With the bare wire technique, the guide wire is first
advanced by itself through the guiding catheter until the distal
tip of the guide wire extends beyond the arterial location where
the procedure is to be performed. Then a rail type catheter, such
as described in U.S. Pat. No. 5,061,273 (Yock) and the previously
discussed McInnes et al., which are incorporated herein by
reference, is mounted onto the proximal portion of the guide wire
which extends out of the proximal end of the guiding catheter
outside of the patient. The catheter is advanced over the catheter,
while the position of the guide wire is fixed until the operative
means on the rail type catheter is disposed within the arterial
location where the procedure is to be performed. After the
procedure, the intravascular device may be withdrawn from the
patient over the guide wire or the guide wire advanced farther
within the coronary anatomy for an additional procedure.
[0009] There has been an interest in creating different surface
profiles for the guide wire core. The interest arose primarily to
address the issue of friction between the contact surface of the
guide wire and the catheter lumen through which it passes or the
body lumen of the patient. One attempt is the use of a sleeve at
the distal portion of the core as seen in, for example, U.S. Pat.
No. 5,404,887 (Prather). Another approach to reducing the surface
contact between the guide wire and a catheter lumen or body lumen
is shown in U.S. Pat. No. 6,296,616 (McMahon).
SUMMARY OF THE INVENTION
[0010] The present invention in various embodiments is directed to
reducing the surface contact of the guide wire within a catheter
lumen or a body lumen, and providing a unique tactile feedback to
the clinician or physician thus improving his or her control and
awareness of wire movement. The present invention further
diminishes the potential for generating particulate in the
lubricious hydrophilic coating during motion of the guide wire in a
catheter, because of the reduced contact between the catheter lumen
and the guide wire surface. Lastly, the present invention provides
a guide wire surface that minimizes the phenomenon of "watermelon
seeding," which describes the inadvertent shifting of the guide
wire relative to the lesion when the two structures catch and then
overslip due to the low friction of the guide wire coating.
[0011] In one embodiment, the present invention contemplates an
intraluminal guide wire comprising an elongated core having a
proximal core section and a distal core section having a distal
end, wherein at least a section of the elongated core includes at
least one of randomized or non-randomized tactile surface contours.
The guide wire preferably includes an uninterrupted polymer coating
made of generally uniform thickness adhering to at least a portion
of the elongated core and having a surface contour that follows the
at least one of randomized and non-randomized tactile surface
contours in the elongated core. Thus, in this embodiment, the
randomized or non-randomized tactile surface contour in the
elongated core and elsewhere is translated into a like contour at
the polymer coating surface. In other words, bumps in the surface
of the wire core translate to bumps in the surface contour or
texture of the polymer coating. Preferably, the coating has a
generally uniform thickness over the surface contours as well as
the flat areas of the wire core.
[0012] In another embodiment of the present invention, a guide wire
comprises an elongated core having a proximal core section and a
distal core section including a taper transitioning to a distal end
wherein an exterior surface of the distal core section is
relatively smooth. In one variation, a polymer coating of uniform
thickness adheres to at least a portion of the distal core section
and follows the profile of the taper. In another variation, the
outside diameter (O.D.) of the polymer coating does not follow the
tapered profile although the inside diameter (I.D.) does follow the
taper. This results in a constant O.D. for the guide wire even at
the taper and the coating has a variable thickness. In either
variation, the polymer coating has at least one of randomized or
non-randomized tactile surface contours.
[0013] The surface contours in this embodiment are generated in the
surface of the polymer coating only and do not originate from the
surface texture of the underlying wire core. With the polymer
coating that has a generally uniform thickness along the length of
the guide wire, the specific coating section with its surface
irregularity creating the surface contour or texture is still
loosely described as having a uniform thickness. And the uniform
thickness polymer coating follows the profile of the core such as
in a tapered or step down transition.
[0014] In various embodiments of the present invention, the surface
contour can include a bump, a divot, a helical groove pattern, a
rib, an undulation, a longitudinal groove, ridges and dips, a
circumferential groove, or the like. As mentioned above, these
tactile surface contours may be generated in the surface of the
polymer coating only or may originate in the surface of the wire
core which then is translated into the outer surface of the polymer
coating.
[0015] The present invention further contemplates a method for
providing an intraluminal guide wire comprising the steps of
providing an elongated core having a proximal core section and a
distal core section having a smooth exterior surface. The method
further includes tapering the profile of the elongated core to
transition into a distal end, and heating and extruding a polymer
through a die to adhere to at least a portion of the elongated core
to create a polymer coating of generally uniform or variable
thickness, and imparting into the polymer coating at least one of
randomized and non-randomized tactile surface contours.
[0016] In various alternative embodiments, the present invention
includes localized heating of the polymer coating to create the
surface texture. The localized heating may originate from a laser
or a heat source that is brought into proximity of the polymer
coating in cycles or randomly at various predetermined feed rates
over the wire core. Moreover, the surface contours or texture in
the wire core or even the polymer coating can be generated by sand,
shot, or particle blasting the wire core or by drawing through a
die to create a ridge, for example. These and other advantages of
the invention will become more apparent from the following detailed
description when taken in conjunction with the accompanying
exemplary drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a side elevational view partially in section of
one embodiment of the present invention guide wire.
[0018] FIG. 2 is a cross-sectional view taken along line 2-2 in
FIG. 1 showing a coating over the wire core.
[0019] FIG. 3 is a cross-sectional view taken along line 3-3 of
FIG. 1.
[0020] FIG. 4 is a partial side elevational view of an alternative
embodiment guide wire.
[0021] FIG. 5 is a side elevational view partially in section
showing a guide wire having bumps and conforming contours in the
coating thereon.
[0022] FIG. 6 is a cross-sectional view of the guide wire taken
along line 6-6 of FIG. 5.
[0023] FIG. 7 is a side elevational view of a guide wire partially
in section having a smooth core surface and divots in the coating
thereon.
[0024] FIG. 8 is a cross-sectional view taken along line 8-8 in
FIG. 7.
[0025] FIG. 9 is a side elevational view of a guide wire partially
in section showing pitted or divots in the core surface and a
conforming surface texture in the coating thereon.
[0026] FIG. 10 is a cross-sectional view taken along line 10-10 of
FIG. 9.
[0027] FIG. 11 is a side elevational view of a guide wire partially
in section showing a smooth surface on the wire core with ridges
formed in the coating.
[0028] FIG. 12 is a cross-sectional view taken along line 12-12 of
FIG. 11.
[0029] FIG. 13 is a partial side elevational view of a distal core
section of a wire core with a partial cross-section showing a
helical surface contour in the coating.
[0030] FIG. 14 is a partial side elevational view, partially in
cross-section, showing an undulating surface contour.
[0031] FIG. 15 is a partial side elevational view, partially in
cross-section, showing longitudinal grooves in the surface
contour.
[0032] FIG. 16 is a partial side elevational view, partially in
cross-section, showing randomized pits or divots in the wire core
surface and conforming surface contours in the coating thereon.
[0033] FIG. 17 is a shematic view of a coating process in which the
polymer and wire core are extruded through a die.
[0034] FIG. 18 is a perspective view of a V-block fixture used to
hold a wire core for laser cutting a surface texture therein.
[0035] FIG. 19 is a partial side elevational view of a distal core
section of a wire core with a partial cross-section showing a
helical surface contour in the variable thickness coating, and
showing the coating having a constant outside diameter (O.D.).
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0036] The present invention is directed to an elongated
intracorporeal device such as a guide wire having a surface
texture. The surface texture depending on location is helpful for
minimizing friction between the guide wire and the catheter lumen
or body lumen, and provides tactile feedback to the physician if
located at the proximal end. In various embodiments, the tactile
and friction-reducing surface texture in the guide wire coating is
created from texturing the guide wire core underneath which is
translated to the coating surface. Alternatively, the texturing is
created solely in the surface of the coating that overlies a smooth
surface of the wire core.
[0037] FIG. 1 is a side elevational view partially in section of
one embodiment of the present invention guide wire 10. The guide
wire 10 includes an elongated core having a proximal core section
12 and a distal core section 14. In this embodiment, the entire
wire core is made from a single material such as stainless steel.
In various alternative embodiments (not shown), the proximal core
section can be made from a high strength steel while the distal
core section 14 is made from a superelastic alloy such as
nickel-titanium or the like. The two core sections can be joined by
a weld or adhesive, and/or by an interconnecting hypotube made from
various materials.
[0038] Returning to FIG. 1, the guide wire 10 includes optional
tapered sections 16, 18. Specifically, the present invention
contemplates one or more tapered profiles at varying degrees of
taper, although straight, curved, and/or stepped profiles are also
contemplated. The guide wire 10 further includes a coating 20
disposed on and adhering to the wire core 22. The surface coating
20 or the surface of the wire core 22, or both, include surface
textures as illustrated in FIGS. 5-16. For simplicity in
illustration, the surface textures are not shown in FIGS. 1-4.
[0039] The surface coating 20 may only partially cover the guide
wire core 22 or may envelope the entire core altogether. Toward the
distal end 24 of the guide wire 10 is a flexible member 26.
Preferably the flexible member 26 is one or more helical coils
welded, bonded, soldered, or otherwise attached to the distal core
section 14. In the embodiment shown, the flexible member 26 is
attached at its proximal end by a weld or solder mass 28 and at its
distal end by a solder ball 30 or similar rounded tip. Furthermore,
the guide wire 10 features a flattened distal tip that extends into
the solder ball 30. FIGS. 2 and 3 are cross-sectional views of the
guide wire 10 taken along lines 2-2 and 3-3 of FIG. 1,
respectively.
[0040] FIG. 4 is a partial side elevational view of the distal core
section 34 of an alternative embodiment guide wire that has a
separate shaping ribbon 36 extending from the distal extremity of
the wire core 38 or, as shown, from the weld mass 40. The guide
wire in FIG. 4 has optional tapered sections 16, 18 as seen in FIG.
1 and an optional solder ball 30. The FIG. 4 embodiment also has a
flexible member 26. The coating 22 shown in FIGS. 1 and 2 may
extend beneath the flexible member 26 or terminate at any point
along the length of the wire core.
[0041] FIGS. 5-16 depict various embodiments creating a textured
surface in the guide wire according to the present invention. In
these drawings, the surface textures have been exaggerated in their
relative size to better illustrate their unique features, and
accordingly, the drawings are not to scale.
[0042] FIG. 5 is a side elevational view of a guide wire 42 similar
in construction to that shown in FIG. 1. The guide wire at the
distal end 44 includes one or more flexible members 46 surrounding
a flattened distal end 48.
[0043] The guide wire 42 of FIG. 5 includes optional tapered
sections 50, 52 transitioning distally to a flattened distal end
48. Moving proximally, the tapered section 50 transitions into a
straight proximal core section 54 terminating at the proximal end
56. As best illustrated in the partially cross-sectioned area in
FIG. 5, the wire core 64 of the guide wire 42 includes bumps 58
disposed along the surface thereof. These bumps 58 may be in an
organized, non-randomized pattern with uniform shapes and sizes; or
they may be randomized in their locations, sizes and shapes.
[0044] Indeed, the bumps 58 have sufficient amplitude or height to
change the surface contour, but the generally straight or tapered
profile of the wire core remains unchanged. In other words, the
bumps 58 change the surface texture of the wire core, but do not
change and are independent of the overall profile of the wire core,
be it straight, tapered, stepped, curved, or any combination
thereof.
[0045] Overlying the wire core 64 is a coating 60 that in this
embodiment preferably extends from the proximal end 56 to a weld
mass 62. Importantly, the coating 60 follows or conforms to the
surface texture delineated by the bumps 58 as well as the overall
profile delineated by the straight, curved, or tapered profiles of
the wire core 64. In other words, as the outside diameter of the
wire core 68 changes, so does the outside diameter of the coating
60 such that the coating thickness is relatively constant along the
length of the wire core 68.
[0046] FIG. 6 is a cross-sectional view of the guide wire 42 taken
along line 6-6 of FIG. 5. This cross-sectional view shows the wire
core 64 having bumps 58 disposed in a regular pattern at 90 degrees
apart around its circumference. FIG. 6 further shows the coating 60
with a relatively uniform thickness around the circumference and
having bumps in its surface conforming to the bumpy surface texture
of the underlying wire core 64.
[0047] In the embodiment shown in FIG. 5, the bump 58 pattern in
the wire core 64 extends almost the entire length of the wire core
64. Naturally, the bump pattern may cover only a portion thereof,
and the bumps 58 may be interspersed in patterns other than that
shown in FIG. 5. Also, the wall thickness of the coating 60 is
generally uniform, but in alternative embodiments may be thicker or
thinner at those locations overlying the bumps 58.
[0048] The bumps 58 in the wire core 64 can be created by liquid
metal sputtering or like metallization techniques, or from solder,
braze, weld, adhesive beads deposited onto the surface of the wire
core 64. The coating 60 is then built up on the bumpy substrate
thus creating the bumpy textured surface shown in FIG. 5.
[0049] FIG. 7 is a side elevational view partially in section of an
alternative embodiment guide wire 66. In this embodiment, the wire
core 68 has a single tapered section 70 transitioning into a
flattened distal end 72 in the distal direction, while
transitioning to a straight proximal core section 74 in the
proximal direction. The overall profile of the wire core 68
includes the straight proximal core section 74 and the tapered
section 70.
[0050] The surface of the wire core 68 is relatively smooth without
any surface texture or contour. However, a coating 76 deposited on
the smooth surface wire core 68 itself has surface textures in the
form of spaced apart divots 78. As seen in the partial sectional
view of FIG. 7, the coating 76 generally follows the straight
profile or tapered profile of the wire core 68, with a thickness of
the coating that is generally uniform except at the divots 78 where
the thickness is diminished by the depth of the divots 78. In
various alternative embodiments, the depths of the divots may range
from just a slight indentation in the coating surface to a through
hole exposing the wire core surface. In this embodiment, the
surface texturing by way of the divots 78 is concentrated at the
tapered section 70 while the proximal core section 74 has no
surface texturing in the coating or in the surface of the wire core
68.
[0051] FIG. 8 is a cross-sectional view of the wire core 68 taken
along line 8-8 of FIG. 7. As seen in this view, the divots 78 are
preferably spaced around the circumference of the wire core 68 in
approximately 45 degree increments. These types of divot patterns
in the coating 76 can be generated by, for example, laser drilling,
molding, casting, local application of heat, or the like.
[0052] FIG. 9 is a side elevational view, partially in section, of
another alternative embodiment guide wire 80. This guide wire 80
features a distal end 82 and a proximal end 84 with tapered
sections 86, 88 therebetween. The tapered sections 86, 88 proximate
to the distal end 82 have divots 90 that are spread along the
surface of the wire core 92. Similar to the embodiment in FIG. 5,
these surface impressions or depressions on the wire core 92 are
translated into the surface texture of the overlying coating 94.
Also, the coating 94 generally follows the straight, curved,
stepped, or tapered profile of the wire core 92 while maintaining a
generally uniform thickness along the length thereof. At the divots
90, the indentation of the substrate is duplicated in an overlying
indentation or divot in the coating surface. Accordingly, the
divots 90 in the wire core surface are generally duplicated in the
surface of the coating 94.
[0053] FIG. 10 is a cross-sectional view of the guide wire 80 taken
along line 10-10 of FIG. 9. The cross-sectional view shows the
divots 90 dispersed 360 degrees around the circumference of the
wire core surface and likewise the indentations are translated to
the surface of the coating 94 that surrounds the wire core.
[0054] The pattern of indentations, pits, or divots 90 shown in
FIG. 9 can be created by, for example, laser cutting, EDM,
mechanical rolling with a patterned die, stamping, or the like. The
pattern of divots 90 may be uniform as shown in FIG. 9, or may be a
randomized pattern with varying divot sizes. Further, the pattern
of divots or similar surface texturing may be concentrated at a
specific portion of the guide wire or along the entire length
thereof. The depth of the divots 90 can be controlled by the energy
applied during the laser cutting or EDM processes, by the size of
the relief pattern in the rolling die and the pressure applied by
it to the surface of the wire core, by bead blast intensity and
velocity, or the like.
[0055] FIG. 11 is a side elevational view of another alternative
embodiment guide wire 96. In this embodiment, the partial
cross-sectional view shows a smooth surface wire core 98 with a
straight 100, tapered 102, 104, or curved (not shown) profile. A
coating 106 in the FIG. 11 embodiment covers those straight and
tapered profile sections. The coating 106 has a generally uniform
thickness along these sections and conforms to the straight or
tapered profile. Furthermore, the coating 106 has ridges 108
randomly positioned along the length of the wire core 98. The
ridges 108 rise above the surface of the coating 106 and span the
circumference of the wire core 98. As such, the coating 106 has a
generally uniform wall thickness except at the ridges 108 where the
wall thickness increases slightly.
[0056] FIG. 12 is a cross-sectional view taken along line 12-12 of
FIG. 11 showing the generally untextured outer surface of the wire
core 98 and a ridge 108 just proximal to the section cut line.
Therefore, in this embodiment, the ridges 108 formed into the
surface of the coating 106 form the textured or contoured
surface.
[0057] FIG. 17 shows one preferred process for creating a coating
with surface texturing; the surface texturing here are ridges 108.
In FIG. 17, guide wire 96 is fed through a die 110 having a tapered
orifice 112. The wire core 98 again has straight and tapered
profiles. A solid polymer cartridge 114 surrounds the wire core 98
as it passes through a lumen 116 therein. Proximate to the die 110
is a heat source 118 used to melt the polymer nearest the die 110.
A plunger 120 also applies pressure on the cartridge 114 forcing
melted polymer into the orifice 112 as the wire core 98 passes
therethrough. Accordingly, the wire core 98 is fed in the direction
of the arrow shown in FIG. 17 while the polymer cartridge 114 is
simultaneously melted by the heat source 118 and force fed into the
orifice 112 under plunger pressure 120.
[0058] If this process proceeds without disturbance, a generally
uniform and concentric coating is adhered to the surface of the
wire core. However, if the feed speed through the die 110 is
changed, or the feed is stopped, for example, a ridge 108 is formed
as shown in FIG. 17. More background details of the process are
described in U.S. Pat. No. 6,419,745 (Burkett et al.), titled
"Method and Apparatus for Polymer Application to Intracorporeal
Devices," whose entire contents are hereby incorporated by
reference.
[0059] Other parameters that can be adjusted to build the ridges
108 in FIG. 17 include heating the polymer cartridge 114 to a
higher temperature with a greater fluid flow rate while slowing the
feed rate of the wire core 98. This results in a greater deposit or
thickness in the coating 106 as compared to the other portions of
the coating 106. Also, resuming to normal feed speed after a speed
change or interruption changes the thickness of the coating 106
deposited on the substrate. Furthermore, the height of the ridges
108 above the surface of the coating 106 can be adjusted by changes
in the relative feed speed and/or by adjusting the flow rate of the
melted polymer as controlled by plunger pressure and heat source
temperature. Indeed, in one embodiment, the raised ridges 108 can
be created by momentarily increasing the plunger pressure against
the cartridge 114 thus momentarily depositing an extra amount of
melted polymer on the substrate. This occurs while all of the other
processing parameters remain constant. Through the aforementioned
processes, the ridges 108 can be spaced apart uniformly or randomly
spaced.
[0060] FIGS. 13-16 show various alternative embodiment surface
textures. It is acknowledged that these drawings show the coatings
on a tapered portion of the wire core, but it is understood that
the textured surfaces can be generated at any part of the wire core
along its length. Again, the relative size of the texturing has
been exaggerated for the sake of illustration.
[0061] FIG. 13 shows a partial side elevational view of a wire core
122 having a coating 124 that features circumferential grooves 126
that are preferably formed into a helical pattern. This pattern can
be generated in the surface of the coating 124 through a fixture
shown in FIG. 18. A V-block 128 has a V-shaped groove or notch that
receives the length of a wire core 130. Situated preferably
perpendicular to the longitudinal axis of the wire core 130 is a
laser 132 with a lens aperture 134 immediately adjacent to the wire
core 130 at or near the vertex of the notch of the V-block 128. As
the wire core 130 is fed lengthwise as indicated by the arrow, the
wire core 130 is rotated in a clockwise or counterclockwise
direction. The laser 132 is energized and cuts a pattern in the
coating that resembles the helically grooved 126 surface texture
shown in FIG. 13. Naturally, the intensity of the laser and the
feed and rotational speed of the wire core 130 through the V-block
128 affect the final surface configuration and depth of the grooves
126.
[0062] FIG. 14 is a partial side elevational view of a wire core
136 with a coating 138. An initial uniform thickness coating over
the wire core 136 can be achieved by the process disclosed in
connection with FIG. 17 and U.S. Pat. No. 6,419,745 (Burkett et
al.). The application of heat to create the surface undulations
would thus be a subsequent step. In this embodiment, the coating
138 has an undulating surface texture created by moving a heat
source 140 close to and then away from the coating 138. This action
melts portions of the coating 138 while not affecting other
portions thus generating the wavy surface texture. The heat source
140 can be in the form of a hot mold that closes down on the wire
to form the surface wave pattern. Another option involves a fixture
that would place the wire core 136 inside a series of heated coils.
Heating coils close to the coating 138 cause the polymer to flow
away from the heat source again creating the wavy surface
texture.
[0063] FIG. 15 is a partial side elevational view of a wire core
142 having a coating 144 that features longitudinal or lengthwise
grooves 146 creating the surface texture. The longitudinal grooves
146 preferably do not extend deeply into the coating 144 to prevent
segmenting the coating into discrete pieces. Such longitudinal
grooves 146 can be laser cut into the coating 144 through a process
such as that shown in FIG. 18 using a V-block 128.
[0064] FIG. 16 is a partial side elevational view of a wire core
148 with a coating 150 having random divots 152 formed therein. The
divots 152 in the coating originate from divots 154 or pits formed
into the surface of the wire core 148. These divots 154 are
preferably created by shot, bead, sand or particle blasting the
surface of the wire core 148 thus generating the randomly pitted or
scarred surface texture. The surface texture of the wire core 148
translates to corresponding pitting or divots 152 in the surface
coating 150.
[0065] FIG. 19 shows an embodiment very similar to that shown in
FIG. 13 in a partial side elevational view of a wire core 122
having a coating 124' that features circumferential helical grooves
126. In this embodiment, however, the outside diameter (O.D.) of
the polymer coating 124' is constant along the length of the core
while the inside diameter (I.D.) follows and adheres to the overall
profile of the wire core 122, here a taper. Therefore, in this
embodiment, the thickness of the polymer coating 124' varies along
the length of the core 122 and is not uniform. The variable
thickness coating 124' can be adapted to any of the foregoing
embodiments shown in FIGS. 5-16.
[0066] The present invention coating as mentioned in the above
embodiments is preferably a polyurethane polymer, although any
polymer that meets design requirements can be used. The spacing
between surface textures or contour interruptions range between
about 0.1 cm to 0.3 cm along the length of the wire core. In one
embodiment, the textured polymer coating is located on the distal
working section of the wire core, which is typically between 25 to
45 cm from the distal tip of the wire core and more preferably the
distal 45 cm, although the polymer coating may be terminated at the
distal tip coils as shown in FIG. 5, 7, 9, or 11, for example. In
another preferred embodiment, the amplitude or height above the
main polymer coating surface of the surface texture interruption
would be from 0.0002 to 0.002 inch, with the preferred embodiment
having an amplitude between 0.0005 and 0.001 inch. Reasonable
spacing between surface texture interruptions would be preferably
between 0.1 to 0.2 cm and could range from 0.05 to 2 cm.
[0067] In various alternative embodiments, the surface coating can
be made from a fluoropolymer or fluoropolymer resin materials. The
surface could then be randomly or non-randomly textured,
resurfaced, or scarred using a laser, UV light, radiation, or other
forms of heat and energy transmission. As mentioned earlier, the
texturing of the surface of the wire core can be any mechanical
means such as textured rollers, scraping, dimpling, impingement,
sand blasting using aluminum oxide, carbide, sodium bicarbonate
powders, stamping, pad printing, etc.
[0068] The fluoropolymer coating may be co-extruded onto the wire
core through the process described in connection with FIG. 17. Such
a fluoropolymer may be PTFE or any type of fluoropolymer based
material, blended fluoropolymer with other non-fluoropolymers,
primed, layered, impinged, baked, chemically adhered on one or more
layers with any/either PTFE, FEP, Teflon 1 coats, PTFE/PFA blends,
PFA, ETFE, DuPont Teflon coatings, Xylan coatings, DuPont Teflon S
coating, DuPont Teflon P coating, Akzo Nobel & Acheson
colloids, or other like fluoropolymers. Although not shown, the
textures imparted or formed into the surface of the coating can
include various shapes such as round, oblong, square, rectangle,
triangular, polygonal, teardrop, and other geometric shapes.
[0069] Although not shown, the present invention contemplates more
than one coatings being applied to the wire core. Therefore, the
embodiments shown in the drawing figures may have multiple coatings
yet still reflect the surface textures depicted.
[0070] The wire core 22 may have an optional lubricious coating
such as a fluoropolymer, e.g., Teflon available from DuPont, that
extends the length of the wire core or a portion thereof. The
distal core sections 14, 34, may optionally be covered with a
lubricious coating such as that used by Advanced Cardiovascular
Systems, Inc. under the commercial name MICROGLIDE. Hydrophilic
coatings may also be employed to cover the wire core partially or
entirely.
[0071] The guide wires of the present invention may have typical
guide wire dimensions. Guide wire length may generally be about 90
to about 300 cm, and for use within a patient's coronary anatomy
commercially available guide wires are typically about 175 cm in
length. Longer and longer guide wires, e.g., up to 190 cm in
length, are being offered commercially by a variety of suppliers.
The proximal core section 12 may have a length of about 65 to about
280 cm, preferably about 150 to about 200 cm and a diameter
generally about 0.008 to about 0.035 inch (0.20-0.89 mm), typically
about 0.010 to about 0.020 inch (0.25-0.51 mm) for coronary artery
uses. The distal core section is preferably much shorter than the
proximal core section and generally is about 6 to about 40 cm,
preferably about 8 to about 30 cm in length and tapers in the
distal direction in one or more steps to smaller cross-sectional
dimensions.
[0072] The tapered portion of the distal core section is preferably
followed distally with a manually shapable flattened core segment
or shaping ribbon of about 1 to 4 cm in length which preferably has
essentially constant transverse dimensions, e.g., 0.0005-0.002 inch
(0.013-0.051 mm) by 0.002-0.006 inch (0.051-0.152 mm), typically
about 0.001 by 0.003 inch (0.025-0.076 mm). A helical coil having
transverse outer dimensions about the same as or slightly less than
the proximal core section is secured by its distal end to the
flattened distal tip of the core member, e.g., by means of solder,
and by its proximal end at an intermediate position on the tapered
distal core section so that the distal end of the tapered core
section resides within the interior of the coil. The helical coil
14 may be formed all or in part of stainless steel, a suitable
radiopaque material such as platinum or alloys thereof or other
material such as stainless steel coated with a radiopaque material
such as gold. The wire from which the coil is made generally has a
transverse diameter of about 0.0015 to about 0.003 inch (0.04-0.08
mm) for coronary applications and up to 0.07 inch (0.18 mm) for
peripheral applications. The overall length of the coil 14 is about
2 to about 15 cm, preferably about 2 to about 6 cm. Multiple turns
of the coil 14 may be expanded to provide additional
flexibility.
[0073] Unless otherwise described herein, conventional materials
and manufacturing methods may be used to make the guiding members
of the present invention. Additionally, various modifications may
be made to the present invention without departing from the scope
thereof. Although individual features of embodiments of the
invention may be shown in some of the drawings and not in others,
those skilled in the art will recognize that individual features of
one embodiment of the invention can be combined with any or all of
the features of another embodiment.
* * * * *