U.S. patent application number 13/561193 was filed with the patent office on 2013-02-21 for elongate medical device with continuous reinforcement member.
This patent application is currently assigned to BOSTON SCIENTIFIC SCIMED, INC.. The applicant listed for this patent is Huey Quoc Chan, Stephen Griffin, Elaine Lim. Invention is credited to Huey Quoc Chan, Stephen Griffin, Elaine Lim.
Application Number | 20130046285 13/561193 |
Document ID | / |
Family ID | 37564310 |
Filed Date | 2013-02-21 |
United States Patent
Application |
20130046285 |
Kind Code |
A1 |
Griffin; Stephen ; et
al. |
February 21, 2013 |
Elongate Medical Device with Continuous Reinforcement Member
Abstract
An elongate medical device including an inner elongate member, a
reinforcing member, and an outer tubular member is described. The
reinforcing member may be a helically wound continuous wire
including a first portion having a first cross-sectional profile, a
second portion having a second cross-sectional profile, and a
transition region located between the first portion and the second
portion. The first cross-sectional profile may be different from
the second cross-sectional profile. In some embodiments, the first
cross-sectional profile may be circular or non-circular and the
second cross-sectional profile may be circular or non-circular.
Inventors: |
Griffin; Stephen; (San Jose,
CA) ; Lim; Elaine; (Fremont, CA) ; Chan; Huey
Quoc; (San Jose, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Griffin; Stephen
Lim; Elaine
Chan; Huey Quoc |
San Jose
Fremont
San Jose |
CA
CA
CA |
US
US
US |
|
|
Assignee: |
BOSTON SCIENTIFIC SCIMED,
INC.
Maple Grove
MN
|
Family ID: |
37564310 |
Appl. No.: |
13/561193 |
Filed: |
July 30, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12966816 |
Dec 13, 2010 |
8231551 |
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13561193 |
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11260834 |
Oct 27, 2005 |
7850623 |
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12966816 |
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Current U.S.
Class: |
604/527 ;
604/523; 604/533 |
Current CPC
Class: |
A61M 25/0054 20130101;
A61M 25/0051 20130101; A61M 2025/006 20130101; A61M 25/0045
20130101; A61M 25/0053 20130101; A61M 25/0013 20130101 |
Class at
Publication: |
604/527 ;
604/523; 604/533 |
International
Class: |
A61M 25/00 20060101
A61M025/00; A61M 25/18 20060101 A61M025/18 |
Claims
1. (canceled)
2. A medical device, comprising: a tubular member having a proximal
end and a distal end; wherein the tubular member has a plurality of
slots formed therein; a liner disposed within the tubular member;
wherein the liner has a distal end region disposed distally of the
distal end of the tubular member; and wherein the liner has a
proximal end region disposed proximally of the proximal end of the
tubular member.
3. The medical device of claim 2, wherein the liner includes a
plurality of layers.
4. The medical device of claim 2, wherein the liner includes a
reinforcement layer.
5. The medical device of claim 4, wherein the reinforcement layer
includes a braid.
6. The medical device of claim 4, wherein the reinforcement layer
includes a polymer.
7. The medical device of claim 4, wherein the reinforcement layer
includes a polymer braid.
8. The medical device of claim 2, further comprising a hub secured
to the tubular member and to the liner.
9. The medical device of claim 2, wherein the liner is free from
attachment to the tubular member along at least a portion of the
length of the liner.
10. The medical device of claim 2, wherein the tubular member
includes a nickel-titanium alloy.
11. The medical device of claim 2, wherein a coating is disposed
along an outer surface of the tubular member.
12. The medical device of claim 2, wherein a tip member is disposed
along the distal end region of the liner.
13. The medical device of claim 2, wherein the liner is secured to
the tubular member at one or more attachment points.
14. A catheter, comprising: a catheter shaft, the catheter shaft
including an outer nickel-titanium alloy tubular member and an
inner liner; wherein the outer tubular member has a plurality of
slots formed therein; wherein the inner liner is free from
attachment to the outer tubular member along at least a portion of
the length of the inner liner; wherein the inner liner has a distal
end region disposed distally of a distal end of the outer tubular
member; wherein the inner liner has a proximal end region disposed
proximally of a proximal end of the outer tubular member; and
wherein the inner liner includes a reinforcing member.
15. The catheter of claim 14, wherein the reinforcing member
includes a braid.
16. The catheter of claim 14, wherein the reinforcing member
include a polymer.
17. The catheter of claim 14, wherein the reinforcing member
include a polymer braid.
18. The catheter of claim 14, wherein a tip member is disposed
along the distal end region of the inner liner.
19. The catheter of claim 14, wherein the inner liner is secured to
the outer tubular member at one or more attachment points.
20. A catheter, comprising: a catheter shaft, the catheter shaft
including an outer nickel-titanium alloy tubular member and a
multi-layer inner liner; wherein the outer tubular member has a
plurality of slots formed therein; wherein the inner liner is free
from attachment to the outer tubular member along at least a
portion of the length of the inner liner; wherein the inner liner
has a distal end region disposed distally of a distal end of the
outer tubular member; a tip member disposed on the distal end
region of the inner liner; wherein the inner liner has a proximal
end region disposed proximally of a proximal end of the outer
tubular member; a hub coupled to the proximal end region; and
wherein the inner liner includes a braided reinforcing member.
21. The catheter of claim 20, wherein the braided reinforcing
member includes a polymer.
Description
RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser.
No. 12/966,816, filed Dec. 13, 2010, now U.S. Pat. No. 8,231,551,
which is a continuation of U.S. application Ser. No. 11/260,834,
filed Oct. 27, 2005, now U.S. Pat. No. 7,850,623, the entire
disclosures of which are incorporated herein by reference.
TECHNICAL FIELD
[0002] The invention relates generally to elongate medical devices.
More specifically, the invention relates to an elongate medical
device having a continuous reinforcement member.
BACKGROUND
[0003] Elongated medical devices are commonly used to facilitate
navigation through and/or treatment within the anatomy of a
patient. A variety of elongate medical devices for intraluminal
use, such as catheters, endoscopes, guidewires and the like, have
been developed over the past several decades. Because the anatomy
of a patient may be very tortuous, it is often desirable to combine
a number of performance features in such devices. For example, it
is sometimes desirable that the device have a relatively high level
of pushability and torqueability, particularly near its proximal
end. It is also sometimes desirable that a device be relatively
flexible, particularly near its distal end. A number of different
elongated medical device structures and assemblies are known, each
having certain advantages and disadvantages. However, there is an
ongoing need to provide alternative elongated medical device
structures, assemblies, and methods.
SUMMARY
[0004] The invention provides design, material, and manufacturing
method alternatives for medical devices, such as catheters,
guidewires, and the like. Some embodiments may relate to
alternative shaft structures, assemblies, and methods for elongated
medical devices, such as catheters or guidewires.
[0005] Accordingly, some embodiments may include an inner elongate
member, a continuous wire disposed about at least a portion of the
inner elongate member, and an outer tubular member disposed about
at least a portion of the inner elongate member including the
continuous wire. In one preferred embodiment, the outer tubular
member has a generally constant inside diameter and does not
conform to or fill the spaces between turns of the continuous wire.
In some embodiments, the continuous wire may include a first
section having a first cross-sectional profile, a second section
having a second cross-sectional profile different from the first
section, and a transition region between the first section and the
second section. The first cross-sectional profile may or may not
have a cross-sectional area different from the cross-sectional area
of the second cross-sectional profile.
[0006] The above summary of some embodiments is not intended to
describe each disclosed embodiment or every implementation of the
present invention. The Figures and Detailed Description which
follow more particularly exemplify these embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The invention may be more completely understood in
consideration of the following detailed description of various
embodiments in connection with the accompanying drawings, in
which:
[0008] FIG. 1 is a partial side plan view of a medical device in
accordance with one example embodiment of the invention shown as a
catheter, for example a delivery, guide or diagnostic catheter;
[0009] FIG. 2 is a partial cross-sectional view of a portion of the
medical device of FIG. 1;
[0010] FIG. 3 is a partial cross-sectional view of a portion of the
shaft of the medical device of FIG. 1, including one example of a
distal tip configuration;
[0011] FIG. 4A is a plan view of a portion of the medical device of
FIG. 1 with any layers overlaying a reinforcing layer removed, thus
exposing a continuous reinforcement member helically wound about a
portion of an inner elongate member of the shaft;
[0012] FIG. 4B is a partial cross-sectional view of the portion of
the medical device shown in FIG. 4A and including additional
tubular members overlaying the continuous reinforcement member;
[0013] FIG. 5A is a plan view of a portion of the medical device of
FIG. 1 with any layers overlaying a reinforcing layer removed, thus
exposing an alternative continuous reinforcement member helically
wound about a portion of an inner elongate member of the shaft;
[0014] FIG. 5B is a partial cross-sectional view of the portion of
the medical device shown in FIG. 5A and including additional
tubular members overlaying the continuous reinforcement member;
[0015] FIG. 6 is a perspective view of a portion of a continuous
reinforcement member including a transition region in accordance
with the invention as shown in FIGS. 4A and 4B; and
[0016] FIG. 7 is a perspective view of a portion of a continuous
reinforcement member including a transition region in accordance
with the invention as shown in FIGS. 5A and 5B.
[0017] While the invention is amenable to various modifications and
alternative forms, specifics thereof have been shown by way of
example in the drawings and will be described in detail. It should
be understood, however, that the intention is not to limit the
invention to the particular embodiments described. On the contrary,
the intention is to cover all modifications, equivalents, and
alternatives falling within the spirit and scope of the
invention.
DETAILED DESCRIPTION
[0018] For the following defined terms, these definitions shall be
applied, unless a different definition is given in the claims or
elsewhere in this specification.
[0019] All numeric values are herein assumed to be modified by the
term "about", whether or not explicitly indicated. The term "about"
generally refers to a range of numbers that one of skill in the art
would consider equivalent to the recited value (i.e., having the
same function or result). In many instances, the term "about" may
be indicative as including numbers that are rounded to the nearest
significant figure.
[0020] The recitation of numerical ranges by endpoints includes all
numbers within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75,
3, 3.80, 4, and 5).
[0021] As used in this specification and the appended claims, the
singular forms "a", "an", and "the" include plural referents unless
the content clearly dictates otherwise. As used in this
specification and the appended claims, the term "or" is generally
employed in its sense including "and/or" unless the content clearly
dictates otherwise.
[0022] The following detailed description should be read with
reference to the drawings in which similar elements in different
drawings are numbered the same. The detailed description and the
drawings, which are not necessarily to scale, depict illustrative
embodiments and are not intended to limit the scope of the
invention. The illustrative embodiments depicted are intended only
as exemplary. Selected features of any illustrative embodiment may
be incorporated into an additional embodiment unless clearly stated
to the contrary.
[0023] Refer now to FIGS. 1 and 2, which illustrate a medical
device 10 in accordance with one example embodiment. In general,
the medical device may be a catheter 10, and can include a
generally elongate shaft 12 extending along a central or
longitudinal axis x.
[0024] The axis x extends along the length of the catheter 10 and
necessarily follows the shape and/or curvature of the shaft 12. The
shaft 12 can include a proximal portion 16 having a proximal end
18, and a distal portion 20 having a distal end 22. A distal tip 28
may be disposed at the distal portion 20, and a manifold assembly
14 may be connected at the proximal portion 16 near proximal end
18.
[0025] As an initial matter, it should be appreciated that while
the medical device 10 is depicted as an intravascular catheter 10,
and in particular, an intravascular delivery, guide and/or
diagnostic catheter 10, this is for the purposes of illustration
only. Other medical devices embodying aspects of the invention may
relate to virtually any medical device including an elongate shaft.
For example, other embodiments may relate to medical devices such
as a balloon catheter, an atherectomy catheter, a drug delivery
catheter, a stent delivery catheter, an endoscope, an introducer
sheath, a fluid delivery device, other infusion or aspiration
devices, device delivery (i.e., implantation) devices, guidewires
and the like. Thus, while the Figures and descriptions below are
directed toward a delivery, guide, and/or diagnostic catheter, in
other applications the structure and/or sizes in terms of diameter
and length may vary widely, depending upon the desired properties
of a particular device.
[0026] Additionally, it should be appreciated that the shaft 12,
manifold assembly 14, and distal tip 28 can generally include any
of a broad variety of structures and/or configurations. It should
be understood that the particular configurations and structures
shown and described herein are by way of example only, and that a
broad variety of alternative structures and/or configurations may
be used without departing from the spirit and scope of the
invention as claimed.
[0027] The shaft 12 can be manufactured, include structure, and be
made of materials so as to provide the desired characteristics of
the catheter 10, depending upon the intended use. For example, the
shaft 12 can be provided and/or manufactured so as to maintain a
desired level of flexibility, torqueability and/or other
characteristics appropriate for maneuvering the catheter 10 as
desired, for example, through the vasculature of a patient. As
such, it should be understood that there is a broad range of
possible shaft constructions that may be used, including those
particularly discussed herein and others. Some other examples of
suitable catheter shaft constructions and materials can be found in
U.S. Pat. Nos. 5,569,218; 5,603,705; 5,674,208; 5,680,873;
5,733,248; 5,853,400; 5,860,963; 5,911,715; and 6,866,665, all of
which are incorporated herein by reference. Some additional
examples of shaft constructions include those disclosed in U.S.
patent application Ser. No. 10/238,227 (Publication No.
US-2004/0045645), which is also incorporated herein by
reference.
[0028] The shaft 12 may have a length and an outside diameter
appropriate for its desired use, for example, to enable
intravascular insertion and navigation. For example, in some
embodiments, the shaft 12 may have a length in the range of about 1
cm to about 300 cm or more, or in some embodiments in the range of
about 20 cm to about 250 cm, and an outside diameter in the range
of about 1 F to about 20 F, or in some embodiments, in the range of
about 1 F to about 10 F. Additionally, although depicted as
including a generally round outer diameter and a round
cross-sectional shape, it can be appreciated that the shaft 12 can
include other outer diameter and/or cross-sectional shapes or
combinations of shapes without departing from the spirit of the
invention. For example, the outer diameter and/or cross-sectional
shape of the generally tubular shaft 12 may be oval, rectangular,
square, triangular, polygonal, and the like, or combinations
thereof, or any other suitable shape, depending upon the desired
characteristics.
[0029] In some embodiments, the catheter 10 can be a microcatheter
including a shaft 12 that is adapted and/or configured for use
within small anatomies of the patient. For example, some
embodiments are particularly useful in treating target sites
located in tortuous and/or narrow vessels. Some examples of such
vessels may include those in the neurovascular system, or in
certain sites within the coronary vascular system, or in sites
within the peripheral vascular system such as superficial femoral,
popliteal, or renal arteries. The target site in some embodiments
is a neurovascular site, such as a site in the brain, which is
accessible only via a tortuous vascular path, for example, a
vascular path containing a plurality of bends or turns which may be
greater than about 90.degree. turns, and/or involving vessels which
are in the range of about 8 mm or less, and in some cases as small
as about 2 to about 3 mm or less, in diameter. As such, in some
embodiments, the shaft 12 can include an outside diameter in the
range of approximately 1 F-4 F.
[0030] However, in other embodiments, the catheter 10 may be used
in other target sites within the anatomy of a patient, in which
case the shaft 12 would be so adapted. For example, the catheter 10
may be suited for other uses in the digestive system, soft tissues,
or any other use including insertion into an organism for medical
uses, and the shaft 12 could be appropriately adapted for such
uses. For example, in some embodiments, the catheter 10 may be used
as an introducer sheath, in which case the shaft 12 may be
significantly shorter. The catheter 10 may also include additional
structure and materials adapted for a particular use and/or
procedure. For example, in some other embodiments, the shaft 12 may
include additional devices or structures such as inflation or
anchoring members, device deployment members, sensors, optical
elements, ablation devices, or the like, or any of a broad variety
of other structures, depending upon the desired function and
characteristics of the catheter 10.
[0031] Referring now to FIG. 2, in at least some embodiments, the
shaft 12 can have a generally tubular construction that includes at
least one lumen 15 extending the length of the shaft 12 along the
longitudinal axis x. This can also be seen with reference to FIG.
3, which is a partial cross-sectional view of the shaft. The lumen
15 can be defined by an inner surface 11 of the shaft 12, and can
have an inner diameter capable of transmitting fluids, or in some
cases, receiving another medical device, such as a guidewire, a
stent, a coil (such as an embolic coil, or the like), treatment
particles (such as embolic particles, or the like), an ablation
device, or another catheter, for example, a diagnostic catheter, a
balloon catheter, a stent delivery catheter, or the like, or
others. In some embodiments, the lumen 15 can be adapted and/or
configured to accommodate another medical device having an outer
diameter in the range of about 1 F to about 10 F.
[0032] In one embodiment, the shaft 12 includes a generally tubular
construction including an inner tubular assembly and/or member 24,
and an outer tubular assembly and/or member 26 disposed about at
least a portion of the inner tubular member 24; however it should
be understood that this is by way of example only. The inner
tubular member 24 at least partially defines the inner surface 11
of the shaft 12, and thus defines the lumen 15.
[0033] The inner tubular member 24 can extend from a point within
the distal portion 20 to a point within the proximal portion 16 of
the shaft 12. The length of the inner tubular member 24 can vary
depending upon, for example, the length of the shaft 12, the
desired characteristics and functions of the inner tubular member
24, and other such parameters. In some embodiments, the inner
tubular member 24 can extend substantially the entire length of the
shaft 12, for example, from a point adjacent the proximal end 18 to
a point adjacent the distal end 22. For example, the length of the
inner tubular member 24 can be in the range of about 1-300
centimeters or more, or in some embodiments in the range of about
20 cm-250 cm.
[0034] Referring to FIG. 3, the inner tubular member 24 can include
a proximal portion 33 and a distal portion 35. The proximal and
distal portions 33/35 can be any proximal or distal sections of the
inner tubular member 24. However, in some cases the portions 33/35
can be defined with regard to the relative position of the inner
and outer tubular members 24/26. For example, the distal portion 35
can be any portion of the inner tubular member 24 that extends
distally beyond the distal end 39 of the outer tubular member 26,
while the proximal portion 33 can be any portion of the inner
tubular member 24 that is disposed within, or is proximal of a
distal end 39 of the outer tubular member 26. In some embodiments
inner tubular member 24 may extend proximal of the proximal end of
the outer tubular member 26 to provide a length of tubing to
facilitate attachment of the shaft 12 with a hub assembly 14, or
the like. In some embodiments, the distal portion 35 may be the
portion of the inner tubular member 24 distal of the transition
region (FIGS. 4A, 5A) of the continuous wire of a reinforcing layer
31, and the proximal portion 33 may be the portion of the inner
tubular member 24 proximal the transition region. In some
embodiments, the distal portion 35 can have a length in the range
of about 0.5 cm or greater, or in the range of about 1 cm or
greater, or in the range of about 2 cm or greater, and in some
embodiments in the range of about 3 to about 20 cm or in the range
of about 1.0 to about 1.5 cm. In some embodiments, the distal
portion 35 can be disposed within, and/or be a part of, or
otherwise include a distal tip 28 construction, some examples of
which will be discussed in more detail below.
[0035] The inner tubular member 24 may have an inner diameter, for
example, defining the lumen 15, that is in the range of about 0.01
to about 0.05 inch in size, or in the range of about 0.015 to about
0.03 inch in size, or in the range of about 0.016 to about 0.026
inch in size. As indicated above, however, the lumen 15 (defined by
the inner diameter of the inner tubular member 24) can be adapted
and/or configured (e.g., sized) to accept other material, fluids,
or medical devices, therein, and as such, the size of the lumen 15
can vary, depending upon the desired characteristics and intended
use.
[0036] Additionally, the inner tubular member 24 can have an outer
diameter that is in the range of about 0.011 inch to about 0.055
inch in size, or in the range of about 0.015 inch to about 0.03
inch in size, or in the range of about 0.019 inch to about 0.029
inch in size. It should be understood, however, that these
dimensions are provided by way of example embodiments only and that
in other embodiments, the size of the inner and outer diameter of
the inner tubular member 24 can vary greatly from the dimensions
given, depending upon the desired characteristics and function of
the device.
[0037] The inner tubular member 24, or other portions of the shaft
12, may define one or more additional lumens depending upon the
desired characteristics and function of the catheter 10, and such
additional lumens can be shaped, sized, adapted and/or configured
the same as or different from lumen 15, depending upon the desired
characteristic and functions.
[0038] The inner tubular member 24 may include and/or be made of
any of a broad variety of materials and/or structures. The inner
tubular member 24 may have a single-layer tubular construction or a
multi-layer tubular construction, or a combination thereof. For
example, the inner tubular member 24 may be a single tubular member
formed by a single layer of material, or in other embodiments, may
be formed by a plurality of tubular members and/or a plurality of
layers of material that may be the same and/or different, but in
combination form the inner tubular member 24. In yet other
embodiments, some portions of the inner tubular member 24 can
include a single layer construction, while other portions may
include a multi-layer construction. Some examples of suitable
materials can include, but are not limited to, polymers, metals,
metal alloys, or composites or combinations thereof.
[0039] Some examples of some suitable polymers can include, but are
not limited to, polyoxymethylene (POM), polybutylene terephthalate
(PBT), polyether block ester, polyether block amide (PEBA),
fluorinated ethylene propylene (FEP), polyethylene (PE),
polypropylene (PP), polyvinylchloride (PVC), polyurethane,
polytetrafluoroethylene (PTFE), polyether-ether ketone (PEEK),
polyimide, polyamide, polyphenylene sulfide (PPS), polyphenylene
oxide (PPO), polysulfone, nylon, perfluoro(propyl vinyl ether)
(PFA), polyether-ester, some adhesive resin, such as modified
polyolefin resin, polymer/metal composites, etc., or mixtures,
blends or combinations thereof, and may also include or be made up
of a lubricous polymer. Some other potentially suitable polymer
materials may include those listed below with reference to the
outer tubular member. One example of a suitable polyether block
ester is available under the trade name ARNITEL, and one suitable
example of a polyether block amide (PEBA) is available under the
trade name PEBAX.RTM., from ATOMCHEM POLYMERS, Birdsboro, Pa. In
some embodiments, adhesive resins may be used, for example, as tie
layers and/or as the material of the structures. One example of a
suitable adhesive resin is a modified polyolefin resin available
under the trade name ADMER.RTM., from Mitsui Chemicals America,
Inc. Additionally, polymer material can in some instances be
blended with a liquid crystal polymer (LCP). For example, in some
embodiments, the mixture can contain up to about 5% LCP. This has
been found in some embodiments to enhance torqueability.
[0040] Some examples of suitable metals and metal alloys can
include stainless steel, such as 304V, 304L, and 316L stainless
steel; nickel-titanium alloy such as a superelastic (i.e.,
pseudoelastic) or linear elastic nitinol; nickel-chromium alloy;
nickel-chromium-iron alloy; cobalt alloy; tungsten or tungsten
alloys; tantalum or tantalum alloys, gold or gold alloys, MP35-N
(having a composition of about 35% Ni, 35% Co, 20% Cr, 9.75% Mo, a
maximum 1% Fe, a maximum 1% Ti, a maximum 0.25% C, a maximum 0.15%
Mn, and a maximum 0.15% Si); or the like; or other suitable metals,
or combinations or alloys thereof. In some embodiments, it is
desirable to use metals, or metal alloys that are suitable for
metal joining techniques such as welding, soldering, brazing,
crimping, friction fitting, adhesive bonding, etc.
[0041] Referring to FIG. 3, at least a portion of the inner tubular
member 24 can have a multi-layer tubular construction. The example
shown includes an inner layer 34, an intermediate layer 32 disposed
about the inner layer 34, a reinforcing layer 31 disposed about the
intermediate layer 32, and an outer layer 30 disposed about the
reinforcing layer 31 and the intermediate layer 32. It should be
understood that more or fewer layers can be used, with or without
one or more reinforcing layers, depending upon the desired
characteristics of the inner tubular member 24. Additionally, in
other embodiments, the layers could be arranged differently to
achieve desired properties. For example, the reinforcing layer 31
could be disposed at a different radial location, could be disposed
entirely within another layer, could be disposed on the outer
surface of the inner tubular member 24, or, as indicated above,
could simply be absent. For example, inner tubular member 24 may be
a single or multi-layer member having a discrete reinforcing layer
31 such as a wire coil disposed about inner tubular member 24 along
at least a portion of the length of the inner tubular member 24.
Furthermore, while the layers 30, 32 and 34 are described, these
layers may be provided separately but form a single and/or unitary
layer and/or structure. Some or all of the plurality of layers, for
example layers 30, 31, 32, 34, may be made of any suitable
material, for example, those discussed above for use in the inner
tubular member 24.
[0042] In some embodiments, the inner layer 34 may include a
lubricious polymer such as HDPE or PTFE, for example, or a
copolymer of tetrafluoroethylene with perfluoroalkyl vinyl ether
(PFA) (more specifically, perfluoropropyl vinyl ether or
perfluoromethyl vinyl ether), or the like. In some particular
embodiments, a PTFE tube is used as the inner layer 34, which can
extend the length of the inner tubular member 24.
[0043] Furthermore, in some embodiments, the intermediate and outer
layers 32/30 may each individually include a flexible polymer, for
example a polymer material having a durometer in the range of about
5 D to about 90 D. For example, the intermediate and/or outer
layers 32/30 can include or be made up of one or more tubular
segments of a PEBA, a polyether-ester elastomer, or other like
material. The durometer of the material used to form the
intermediate and/or outer layers 32/30 may be the same, or may vary
from one another, depending upon the characteristics desired. For
example, the intermediate layer 32 may be made of a material having
a higher durometer than the material of the outer 30 layer along at
least a portion of the inner tubular member 24. In other
embodiments, the reverse may be true, and in yet other embodiments,
the two layers 30/32 may include the material having the same or
similar flexibility characteristics.
[0044] In some embodiments, one or both of the layers 30/32 can be
made up of a plurality of tubular segments including materials
having different flexibility characteristics to impart varying
degrees of flexibility to different longitudinal sections of the
intermediate and/or outer layers 32/30. For example, in some
embodiments, one or both of the layers 30/32 can include one or
more proximal segments (e.g., 43/47) and one or more distal
segments (e.g., 45/45). In some cases, the one or more proximal
segments (e.g., 43/47) in either one or both layers 30/32 may
include material having a higher durometer than the material
included in the distal segment (e.g., 45/45) of each or both
respective layer 30/32. Such a construction may be used, for
example, to render a more distal portion of the inner tubular
member 24 more flexible. Such an arrangement can also be helpful,
for example, in providing a flexible distal tip construction, or a
portion thereof.
[0045] For example, referring to the embodiment shown in FIG. 3,
the intermediate layer 32 may include a proximal portion 43
including and/or made of a flexible polymer, such as a PEBA, a
polyether-ester elastomer, or other like material, having a
durometer in the range of about 40 D to about 70 D. The
intermediate layer 32 may also include a distal portion 45
including and/or made of a flexible polymer having a durometer in
the range of about 15 D to about 35 D. Additionally, the outer
layer 30 may include a proximal portion 47 including and/or made of
such a flexible polymer having a durometer in the range of about 25
D to about 55 D. The outer layer 30 may also include a distal
portion 49 including and/or made of such a flexible polymer having
a durometer in the range of about 15 D to about 35 D.
[0046] The inner tubular member 24 can be constructed using any one
or a combination of appropriate methods and/or techniques, for
example, extrusion, co-extrusion, interrupted layer co-extrusion
(ILC), heat bonding techniques, heat shrink techniques, fusing,
winding, disposing, adhesive bonding, mechanical bonding,
soldering, welding, molding, casting, or the like, or others. In
some embodiments, one or more of the layers and/or structures
30/31/32/34 can be formed separately, and thereafter coupled and/or
connected together, while in some embodiments, one or more of the
layers and/or structures 30/31/32/34 can be formed together using
suitable techniques.
[0047] For example, in some embodiments, the layers and/or
structures 30/31/32/34 can be formed separately, such as by
extrusion, co-extrusion, interrupted layer co-extrusion (ILC),
casting, molding, heat shrink techniques, fusing, winding, or the
like, and thereafter coupled or connected together using suitable
techniques, such as heat shrink techniques, friction fitting,
mechanically fitting, chemically bonding, thermally bonding,
welding (e.g., resistance, Rf, or laser welding), soldering,
brazing, adhesive bonding, crimping, or the use of a connector
member or material, or the like, or combinations thereof, to form
the inner tubular member 24.
[0048] In some other embodiments, one or more of the layers and/or
structures of the inner tubular member may be formed together at
the same or similar times using suitable techniques, such as
extrusion, co-extrusion, interrupted layer co-extrusion (ILC), or
the like. In some other embodiments, one or more layers, for
example the inner layer 34 and the reinforcing layer 31, can be
formed and/or provided separately, and thereafter additional
layers, for example layers 32 and 30, can be formed onto, over, or
with the layers 31 and 34 by suitable techniques to form the inner
tubular member 24.
[0049] The inner tubular member 24 may have a uniform stiffness, or
may vary in stiffness along its length. For example, a gradual
reduction in stiffness from the proximal end to the distal end
thereof may be achieved, depending upon the desired
characteristics. The gradual reduction in stiffness may be
continuous or may be stepped, and may be achieved, for example, by
varying the structure, such as the size, thickness, or other
physical aspect of one or more of the layers 30/31/32/34, or for
example, by varying the materials used in one or more of the layers
30/31/32/34. Such variability in characteristics and materials can
be achieved, for example, by using techniques such as ILC, by
fusing together separate extruded tubular segments, or in some
cases, varying the characteristics and/or even the very presence or
absence of certain structures and/or layers.
[0050] The one or more reinforcing layer 31, if present, can be
constructed with any suitable materials and structures to impart
the desired characteristics to the inner tubular member 24. The
reinforcing layer 31 can include one or more support members that
can comprise, for example, a braid, a coil, a filament or wire, or
series of such structures, or the like, including material and/or
structure adapted to provide the desired characteristics. Examples
of suitable materials for constructing the reinforcing layer
include polymers, metals, or metal alloys such as those discussed
above, or the like, or any of a broad variety of other suitable
materials.
[0051] In some embodiments, the reinforcing layer 31 can be a coil
31. The coil 31 may be formed of an elongated filament (e.g., wire,
ribbon, or the like) having appropriate dimensions and shape to
achieve the desired torque, flexibility, and/or other
characteristic. For example, the filament used to form the coil 31
may be circular or non-circular. For instance, the filament may be
flattened, ribbon, oval, rectangular, square, triangular,
trapezoidal, polygonal, and the like, or any other suitable shape.
In describing the filament as being a suitable shape, such as
rectangular, square, triangular, or the like, it is the intention
not to limit the filament to having a true rectangular, square,
triangular, etc., shape. The intention is to include shapes that
resemble such shapes. For example, the filament may have rounded
corners, nonlinear sides, and/or non-characteristic angles. The
coil 31 can be wrapped in a helical fashion by conventional winding
techniques. The pitch of adjacent turns of coil 31 may be tightly
wrapped so that each turn touches the succeeding turn, or the pitch
may be set such that coil 31 is wrapped in an open fashion
maintaining a gap between successive turns. The pitch can be
constant throughout the length of the coil 31, or can vary,
depending upon the desired characteristics, for example
flexibility. For example, in some embodiments, the coil 31 can
include a distal portion including a relatively open pitch, and a
proximal portion having a relatively more closed pitch, such that
the coil is more flexible in the distal portion than in the
proximal portion. The reinforcing layer 31 may extend the entire
length of the inner tubular member 24, or may extend only along a
portion of the length thereof. In some embodiments, the reinforcing
layer 31 may extend from a point distal of the proximal end to the
distal end of the inner tubular member 24. In another embodiment,
the reinforcing layer 31 may extend from the proximal end to a
point proximal of the distal end of the inner tubular member 24. In
still another embodiment, the reinforcing layer 31 may extend from
a point distal of the proximal end to a point proximal of the
distal end.
[0052] One embodiment of the reinforcing layer 31 may be more
clearly described herein. Referring to FIG. 4A, reinforcing layer
31 may be a continuous wire 75. A continuous wire is a single
filament that extends from one end of the wire to the opposite end
of the wire without splicing, welding, brazing or other means of
joining two wires together. A continuous wire 75 may overcome
challenges associated with initiating and/or terminating a
reinforcement member at a location other than the proximal region
or distal region of a catheter construction. Using two or more
discrete coil sections to achieve dissimilar flexibilities
throughout the length of a shaft may be disadvantageous.
Terminating and initiating adjacent coil sections at an
intermediate location may encourage kinking of the shaft, may allow
separation of a reinforcing layer from an inner/outer member, or
may create an uneven transition through the shaft, for example.
[0053] Continuous wire 75 may be helically wound about at least a
portion of inner member 24. Continuous wire 75 may be helically
wound at a constant pitch about a portion of inner member 24, or
the pitch of continuous wire 75 may be varied step-wise or
gradually along a portion of inner member 24. For instance,
continuous wire 75 may be tightly wound (i.e., successive turns are
placed closer together) along a proximal portion 80 of inner member
24 and continuous wire 75 may be more loosely wound (i.e.,
successive turns are spaced farther apart) along a distal portion
82 of inner member 24. Continuous wire 75 may be wound from the
proximal end of inner member 24 to the distal end of inner member
24 or any portion thereof. For example, continuous wire 75 may be
wound from a point distal of the proximal end of inner member 24 to
the distal end of inner member 24, continuous wire 75 may be wound
from the proximal end of inner member 24 to a point proximal of the
distal end of inner member 24, or continuous wire 75 may be wound
from a point distal of the proximal end of inner member 24 to a
point proximal of the distal end of inner member 24.
[0054] As shown in FIG. 4A, inner member 24 may have a lumen 15
extending therethrough. However, in some embodiments, such as a
guidewire, inner member 24 may be a core wire not including a
lumen, such as lumen 15. Lumen 15, if present, may be sized to
provide access to the distal end of the elongate shaft through
lumen 15, for example, to accommodate advancing an additional
medical device therethrough.
[0055] Continuous wire 75 may include a first portion 77, a second
portion 79, and a transition region 78 located between first
portion 77 and second portion 79. Although continuous wire 75 is
shown with one transition region 78, one or more additional
transition regions may be included in continuous wire 75.
Transition region 78 may provide a transition between first portion
77 and second portion 79. Transition region 78 may include a
tapered transition, a step-wise transition, or other such
transition between first portion 77 and second portion 79. For
example, transition region 78 may alternatively be a region of
rotation of continuous wire 75. Continuous wire 75 having different
transverse dimensions may be rotated, for instance by 45, 90, or
180 degrees, through transition region 78 in order to vary the
flexibility of continuous wire 75. For example, continuous wire 75
may be flattened, rectangular, or otherwise have different
transverse dimensions, wherein one of two shorter sides is in
contact with the inner member 24 in the proximal portion 80 of
inner member 24. In transition region 78, continuous wire 75 may be
rotated 90 degrees such that one of two longer sides is in contact
with the inner member 24 in the distal portion 82 of inner member
24. By rotating the continuous wire 75, the radial extent of the
continuous wire 75 from the longitudinal axis x of the elongate
shaft is changed between the proximal portion 80 and the distal
portion 82 of inner member 24. The radial extent of the continuous
wire 75 is intended to mean the distance from the longitudinal axis
x of the elongate shaft to the outermost point of the helically
wound continuous wire 75 in a radial direction. As shown in FIG.
4A, the radial extent R.sub.1 of the first portion 77 of continuous
wire 75 is greater than the radial extent R.sub.2 of the second
portion 79 of continuous wire 75. Continuous wires 75 of other
shapes having different transverse dimensions may be rotated in a
similar manner in order to achieve two or more regions of different
flexibility. By reducing the radial extent of the continuous wire
75 in the distal portion 82 of the inner member 24, the flexibility
of the distal portion 82 is increased. Thus, the second portion 79
of continuous wire 75 having a reduced radial extent may provide a
distal tip portion of the shaft with a higher degree of flexibility
and a lower profile than a portion of the shaft proximal of the
transition region 78.
[0056] As can be better seen in FIG. 4B, a first portion 77 of
continuous wire 75 may have a first cross-sectional profile having
a first cross-sectional area, and a second portion 79 of continuous
wire 75 may have a second cross-sectional profile having a second
cross-sectional area. The first cross-sectional profile may be
constant throughout the first portion 77 of continuous wire 75 and
the second cross-sectional profile may be constant throughout the
second portion 79 of continuous wire 75. Transition region 78 (FIG.
4A) may provide transition between the cross-sectional profile of
the first portion 77 and the cross-sectional profile of the second
portion 79 of continuous wire 75. The first cross-sectional profile
may be dissimilar from the second cross-sectional profile. For
example, the first portion 77 may have a circular cross-sectional
profile and the second portion 79 may have a non-circular
cross-sectional profile, such as a ribbon, oval, flattened, square,
or rectangular profile. The cross-sectional area of the circular
cross-sectional profile may or may not be different from the
cross-sectional area of the non-circular cross-sectional profile.
In other embodiments, the first portion 77 may have a circular or
non-circular cross-sectional profile having a first cross-sectional
area and the second portion 79 may have a circular or noncircular
cross-sectional profile having a second cross-sectional area
different from the first cross-sectional area. For example,
continuous wire 75 may include a proximal portion 77 having a first
circular cross-sectional profile and a distal portion 79 having a
second circular cross-sectional profile. The cross-sectional area
of the first circular cross-sectional profile may be different from
the cross-sectional area of the second circular cross-sectional
profile. For instance, the first cross-sectional area may be
greater than or less than the second cross-sectional area.
Differences in the cross-sectional profile and/or cross-sectional
area of the proximal portion relative to the cross-sectional
profile and/or cross-sectional area of the distal portion 79 may
enhance the flexibility characteristics of the elongate shaft. For
example, the distal portion 79 having a dissimilar profile may
provide the elongate shaft with a very flexible, lower profile
distal tip portion.
[0057] Proximal portion 77 of continuous wire 75 may be helically
wound around a length of inner member 24. For instance, helically
wound proximal portion 77 may extend a majority of the length of
inner member 24. In some embodiments, helically wound proximal
portion 77 may extend a length of about 20 cm or more, about 50 cm
or more, about 75 cm or more, or about 100 cm or more, for example.
Distal portion 79 of continuous wire 75 may be helically wound
around a length of inner member 24. For instance, helically wound
distal portion 79 may extend proximally along inner member 24 from
the distal end of inner member 24, or helically wound distal
portion 79 may extend distally from the proximal end of distal tip
portion 28 to a point within distal tip portion 28. In some
embodiments, distal portion 79 may extend for a length of about 5
cm or less, about 3 cm or less, about 2 cm or less, about 1.5 cm or
less, or about 1 cm or less along a distal portion of inner member
24, for example. Distal portion 79 may be positioned within a
distal tip portion 28 of the shaft. As mentioned previously, the
radial extent R.sub.1 of the proximal portion 77 of the helically
wound continuous wire 75 along proximal portion 80 of inner member
24 may be greater than the radial extent R.sub.2 of the distal
portion 79 of the helically wound continuous wire 75 along distal
portion 82 of inner member 24. Therefore, the portion of the shaft
including the distal portion 79 of continuous wire 75 may have a
lower profile and/or a higher degree of flexibility than the
portion of the shaft including the proximal portion 77.
Additionally or alternatively, a change in the flexibility of the
shaft may be achieved by varying the pitch of the continuous wire
75 between the proximal portion 77 and the distal portion 79.
[0058] As shown in FIG. 4B, an outer tubular member 26 may be
disposed about at least a portion of inner member 24 including the
continuous wire 75. Outer tubular member 26 may be disposed about a
proximal portion of inner member 24 including the continuous wire
75. For reasons of clarity, an additional layer(s) overlaying
continuous wire 75 and disposed within the lumen of outer tubular
member 26 as shown in FIG. 3 is not illustrated in FIG. 4B.
However, some embodiments may include at least one layer of inner
member 24 or an additional layer interposed between continuous wire
75 and outer tubular member 26, or along a portion thereof. In some
embodiments, no additional layer may be located between continuous
wire 75 and outer tubular member 26.
[0059] Distal end 39 of outer tubular member 26 may be located
proximate transition region 78. For example, distal end 39 may be
positioned about 2 cm or less, about 1 cm or less, or about 0.5 cm
or less from transition region 78 of continuous wire 75. Outer
tubular member 26 may extend proximally from a point proximate
transition region 78 to the proximal region of the elongate shaft.
In some embodiments, outer tubular member 26 may extend over the
entire proximal portion 77 of helically wound continuous wire 75.
In some embodiments, outer tubular member 26 may extend from the
proximal end of the elongate shaft to the transition region 78.
However, outer tubular member 26 may extend distal of the
transition region in some embodiments and may extend to the distal
end of the elongate shaft in some embodiments. Outer tubular member
26 may include a plurality of slots or apertures 44 cut through the
wall of outer tubular member 26 to provide a degree of flexibility
to the elongate shaft. In a preferred embodiment, the outer tubular
member has a generally constant diameter over a substantial portion
of its length. Thus, the inside surface does not conform to or fill
the spaces between successive turns of the reinforcing layer. Outer
tubular member 26 will be further described hereinafter.
[0060] A distal tip portion 28 may be disposed about a distal
portion of inner member 24 including the continuous wire 75.
Proximal end 29 of distal tip 28 may be located proximate
transition region 78 such that proximal end 29 of distal tip 28 may
abut or mate with distal end 39 of outer tubular member 26. For
example, proximal end 29 may be positioned about 2 cm or less,
about 1 cm or less, or about 0.5 cm or less from transition region
78 of continuous wire 75. In some embodiments, distal tip 28 may
extend over and surround a distal portion of outer tubular member
26. Distal tip 28 may extend to the distal end of the elongate
shaft to provide a flexible atraumatic tip to the elongate
shaft.
[0061] Another embodiment of reinforcing layer 31 comprising a
continuous wire 175 disposed about at least a portion of inner
member 24 is shown in FIGS. 5A and 5B. Continuous wire 175 may be
similar to continuous wire 75 shown in FIGS. 4A and 4B. Continuous
wire 175 may include a proximal portion 177 having first
cross-sectional profile and a distal portion 179 having a second
cross-sectional profile different from the first cross-sectional
profile. A transition region 178 may be located between the
proximal portion 177 and the distal portion 179 providing a
transition between the two portions of continuous wire 175. The
first cross-sectional profile may be a flattened wire (i.e.,
ribbon) having a first radial extent R.sub.1 and the second
cross-sectional profile may be a flattened wire (i.e., ribbon)
having a second radial extent R.sub.2 less than the first radial
extent R.sub.1. The radial extent of the continuous wire 175 is
intended to mean the distance from the longitudinal axis x of the
elongate shaft to the outermost point of the helically wound
continuous wire 175 in a radial direction. The distal portion 179
having a reduced radial extent may provide the distal tip region of
the shaft with a higher degree of flexibility and a lower profile
segment than more proximal segments.
[0062] As shown in FIG. 5B, an outer tubular member 26 may be
disposed about a proximal portion of inner member 24 including the
continuous wire 175. As mentioned above, an additional layer(s) may
or may not be interposed between outer tubular member 26 and
continuous wire 175. Distal end 39 of outer tubular member 26 may
be located proximate transition region 178. For example, distal end
39 may be positioned about 2 cm or less, about 1 cm or less, or
about 0.5 cm or less from transition region 178 of continuous wire
175. In some embodiments, outer tubular member 26 may extend over
transition region 178 and/or distal portion 179 of continuous wire
175. Outer tubular member 26 may include a plurality of slots or
apertures 44 cut through the wall of outer tubular member 26 to
provide a degree of flexibility to the elongate shaft. Outer
tubular member 26 will be further described hereinafter.
[0063] A distal tip portion 28 may be disposed about a distal
portion of inner tubular member 24 including the continuous wire
175. Proximal end 29 of distal tip 28 may be located proximate
transition region 178 such that proximal end 29 of distal tip 28
may abut or adjoin distal end 39 of outer tubular member 26. For
example, proximal end 29 may be positioned about 2 cm or less,
about 1 cm or less, or about 0.5 cm or less from transition region
178 of continuous wire 175. Distal tip 28 may extend to the distal
end of the elongate shaft to provide a flexible atraumatic tip to
the elongate shaft.
[0064] FIG. 6 shows a portion of continuous wire 75 including a
transition region 78 located between a proximal portion 77 and a
distal portion 79 of continuous wire 75 as disclosed regarding
FIGS. 4A and 4B. Proximal portion 77 may have a circular
cross-sectional profile 72 having a diameter D.sub.1 and distal
portion 79 may have a non-circular cross-sectional profile 73,
which may be a profile having a width W.sub.1 and a height H.sub.1.
Width W.sub.1 may be greater than height H.sub.1. For example,
width W.sub.1 may be two times, four times, or ten times greater
than height H.sub.1. Additionally, diameter D.sub.1 may be greater
than H.sub.1 such that when continuous wire 75 is helically wound
about inner member 24, the radial extent R.sub.1 of the proximal
portion 77 is greater than the radial extent R.sub.2 of the distal
portion 79. In some embodiments, the cross-sectional area of the
cross-sectional profile 72 may be equivalent to the cross-sectional
area of the cross-sectional profile 73. In alternative embodiments,
the cross-sectional area of profile 72 may be greater than or less
than the cross-sectional area of profile 73.
[0065] Distal portion 79 may be formed in continuous wire 75 by
grinding, cold working, drawing, pressing, shaping, chemical
etching, electro-polishing, or otherwise deforming/altering distal
portion 79 of continuous wire 75 into the second cross-sectional
profile 73. In deforming/altering distal portion 79, transition
region 78 is formed, providing a transition between proximal
portion 77 and distal portion 79. Distal portion 79 may have a
specified length such that when distal portion 79 is helically
wound around inner member 24, distal portion 79 extends along inner
member 24 a length of about 0.5 cm to about 5 cm, or about 1 cm to
about 3 cm or about 1 cm to about 1.5 cm, for example. Thus, the
chosen length of distal portion 79 may be a function of the outer
diameter of inner member 24, the pitch of helically wound
continuous wire 75, and/or the number of windings of continuous
wire 75, for example.
[0066] Proximal portion 77 may have a specified length such that
when proximal portion 77 is helically wound around inner member 24,
proximal portion 77 extends a majority of the length of the inner
member 24. In some embodiments, proximal portion 77 may have a
length such that helically wound proximal portion 77 extends about
20 cm or more, about 50 cm or more, or about 100 cm or more, for
example. Helically wound proximal portion 77 may be sized to extend
within about 10 cm or less, about 5 cm or less, about 2 cm or less,
or about 1 cm or less of the proximal end of inner member 24, for
example. Thus, the chosen length of proximal portion 77 may be a
function of the outer diameter of inner member 24, the pitch of
helically wound continuous wire 75, and/or the number of windings
of continuous wire 75, for example.
[0067] FIG. 7 shows a transition region 178 located between a
proximal portion 177 and a distal portion 179 of continuous wire
175 as disclosed regarding FIGS. 5A and 5B. Proximal portion 177
may have a non-circular cross-sectional profile 172, which may be a
ribbon profile having a width W.sub.2 and a height H.sub.2. Width
W.sub.2 and height H.sub.2 may be different, thus cross-sectional
profile 172 may be substantially rectangular (e.g., flat wire), or
width W.sub.2 and height H.sub.2 may be substantially equivalent,
thus cross-sectional profile 172 may be substantially square (e.g.,
flat wire). In describing the cross-sectional profile as square or
rectangular, profiles are intended to resemble those of squares and
rectangles. For example, the cross-sectional profiles may include
rounded corners, nonlinear sides, and/or non-characteristic angles,
thus not creating a true square or rectangular profile. Distal
portion 179 may have a non-circular cross-sectional profile 173,
which may be a ribbon profile having a width W.sub.3 and a height
H.sub.3. Width W.sub.3 may be greater than height H.sub.3, such
that distal portion 179 of continuous wire 175 is a flattened
ribbon portion. In some embodiments, width W.sub.3 may be greater
than width W.sub.2 and/or height H.sub.2 may be greater than height
H.sub.3. For example, width W.sub.3 may be two times, four times,
or ten times greater than width W.sub.2 and/or height H.sub.2 may
be two times, four times, or ten times greater than height H.sub.3.
H.sub.2 may be greater than H.sub.3 such that the radial extent
R.sub.1 of the proximal portion 177 is greater than the radial
extent R.sub.2 of the distal portion 179 when the continuous wire
175 is helically wound around inner member 24. In some embodiments,
the cross-sectional area of the first cross-sectional profile 172
may be equivalent to the cross-sectional area of the second
cross-sectional profile 173. In alternative embodiments, the first
cross-sectional area of profile 172 may be greater than or less
than the second cross-sectional area of profile 173.
[0068] Similar to continuous wire 75, distal portion 179 may be
formed in continuous wire 175 by grinding, cold working, drawing,
pressing, shaping, chemical etching, electro-polishing, or
otherwise deforming/altering distal portion 179 of continuous wire
175 into the second cross-sectional profile 173. In
deforming/altering distal portion 179, transition region 178 is
formed providing a transition between proximal portion 177 and
distal portion 179. Distal portion 179 may have a specified length
such that when distal portion 179 is helically wound around inner
member 24, distal portion 179 extends along inner member 24 a
length of about 0.5 cm to about 5 cm, or about 1 cm to about 3 cm
or about 1 cm to about 1.5 cm, for example. Thus, the chosen length
of distal portion 179 may be a function of the outer diameter of
inner member 24, the pitch of helically wound continuous wire 175,
and/or the number of windings of continuous wire 175, for
example.
[0069] Proximal portion 177 may have a specified length such that
when proximal portion 177 is helically wound around inner member
24, proximal portion 177 extends a majority of the length of the
inner member 24. In some embodiments, proximal portion 177 may have
a length such that helically wound proximal portion 177 extends
about 20 cm or more, about 50 cm or more, or about 100 cm or more,
for example. Helically wound proximal portion 177 may be sized to
extend within about 10 cm or less, about 5 cm or less, about 2 cm
or less, or about 1 cm or less of the proximal end of inner member
24, for example. Thus, the chosen length of proximal portion 177
may be a function of the outer diameter of inner member 24, the
pitch of helically wound continuous wire 175, and/or the number of
windings of continuous wire 175, for example.
[0070] Referring again to FIGS. 1-3, the outer member 26 can also
be a generally tubular member including a proximal region 36 having
a proximal end 37 and a distal region 38 having a distal end 39.
The outer tubular member 26 can be disposed about at least a
portion of the inner tubular member 24 at a location along the
length of the shaft 12 between proximal end 18 and distal end 22.
In the embodiment shown, the outer member 26 is disposed about the
inner tubular member 24 along the proximal portion 16 of the shaft
12, but it should be understood that other locations are
possible.
[0071] The length of the outer tubular member 26 can also vary,
depending upon, for example, the length of the shaft 12, the
desired characteristics and functions of the catheter 10, and other
such parameters. In some embodiments, the outer member 26 has a
length that allows it to be disposed over the majority of the
length of the inner tubular member 24, and in some embodiments, is
disposed about all but up to the distal most 15 cm or less of the
inner tubular member 24 and/or all but the proximal most 15 cm or
less of the inner tubular member 24. In some embodiments, the
distal end of the outer tubular member 26 is disposed about 3.0 cm
or less, 2.0 cm or less, 1.5 cm or less or 1.0 cm or less proximal
the distal end of the inner member 24. In some embodiments, the
length of the outer tubular member 26 can be in the range of about
1 cm to about 299 cm or more, or in some embodiments in the range
of about 19 cm-249 cm.
[0072] The tubular outer member 26 defines a lumen 40 that can be
adapted and/or configured to house or surround a portion of the
inner tubular member 24. In some embodiments, the lumen 40 can have
an inner diameter that is in the range of about 0.015 inch to about
0.06 inch in size, and in some embodiments, in the range of about
0.02 inch to about 0.035 inch in size. In some embodiments, the
outer tubular member 26 can have an outer diameter that is in the
range of about 0.016 inch to about 0.07 inch in size, or in the
range of about 0.02 inch to about 0.04 inch in size. It should be
understood however, that these, and other dimensions provided
herein, are by way of example only.
[0073] In at least some embodiments, the outer tubular member 26
can have an inner diameter that is greater than the outer diameter
of the inner tubular member 24. As such, the outer tubular member
26 can be disposed about the inner tubular member 24 (i.e., a
portion of the inner tubular member 24 is disposed within the lumen
40 of the outer member) such that a space or gap 42 is defined
between at least a portion of the outer surface 25 of the inner
tubular member 24 and the inner surface 27 of the outer member 26.
In some embodiments, the space or gap 42 can be in the range of
about 0.0002 to about 0.004 inch in size, and in some embodiments,
in the range of about 0.0005 to about 0.003 inch in size. Again, it
should be understood that these dimensions are provided by way of
example only. In some embodiments, space or gap 42 may be
substantially filled by reinforcing layer 31. For example,
continuous wire 75 may be disposed in gap 42 between inner member
24 and outer tubular member 26. However, in some embodiments the
outer tubular member 26 is substantially contiguous with the inner
tubular member 24 such that no gap or space is formed between the
inner tubular member 24 and the outer tubular member 26.
[0074] Typically, relatively large portions of the gap or space 42
remain open or unfilled by any other structure of the catheter 10
along a substantial portion of the length thereof, and in some
cases along a substantial portion of the length of the outer
tubular member 26. For example, in some embodiments, 50% or more,
75% or more, 90% or more, or 95% or more of the gap or space 42
remains open and/or unfilled by any other structure of the
catheter.
[0075] In some embodiments, attachment points along the length of
the outer tubular member 26 may be used to attach to the inner
tubular member 24. As a result, the gap or space 42 may be
partially or totally filled at these attachment points, and as
such, divided up into what may be considered multiple and/or a
plurality of separate gaps or spaces that are unfilled.
Additionally, other structures, such as coils, bands, braids,
polymer layers, or the like, may fill portions of the gap or space
42. Even so, such multiples of the gap or space 42, or the so
defined multiple gaps or spaces 42 may still collectively extend
along a substantial portion of the length of the outer tubular
member 26 and remain overall substantially unfilled over the
majority of the length thereof, for example, in percentages of the
total length as given above. As such, the outer tubular member 26
can act to reinforce or impart desired properties, such as
torsional and lateral rigidity, to the catheter shaft 12, and may
allow at least the portion of the inner tubular member 24
surrounded by the gap or space 42 to be separate from, and in some
cases bend and/or move laterally within, the lumen 40. Some
examples of structure, methods, and techniques of coupling the
tubular outer member 26 to the inner tubular member 24 will be
discussed in more detail below.
[0076] The outer tubular member 26 can be adapted and/or configured
to have a desired level of stiffness, torqueability, flexibility,
and/or other characteristics. Those of skill in the art and others
will recognize that the dimensions, structure, and materials of the
outer tubular member 26 are dictated primarily by the desired
characteristics, and the function of the final catheter 10, and
that any of a broad range of the dimensions, structure, and
materials can be used.
[0077] The desired stiffness, torqueability, lateral flexibility,
bendability or other such characteristics of the outer member 26
can be imparted or enhanced by the structure of the outer tubular
member 26. For example, the outer tubular member 26 may include a
thin wall tubular structure, including one or a plurality of
apertures 44, such as grooves, cuts, slits, slots, or the like,
formed in a portion of, or along the entire length of, the tubular
outer member 26. Such structure may be desirable because it may
allow outer tubular member 26, or portions thereof, to have a
desired level of lateral flexibility as well as have the ability to
transmit torque and pushing forces from the proximal region 36 to
the distal region 38. In some embodiments, slots or apertures 44
may extend substantially transverse to the longitudinal axis x of
the outer tubular member 26. The apertures 44 can be formed in
essentially any known way. For example, apertures 44 can be formed
by methods such as micro-machining, saw-cutting, laser cutting,
grinding, milling, casting, molding, chemically etching or
treating, or other known methods, and the like. In some such
embodiments, the structure of the outer tubular member 26 is formed
by cutting and/or removing portions of the tube to form apertures
44.
[0078] In some embodiments, the apertures 44 can completely
penetrate the outer tubular member 26 such that there is fluid
communication between the lumen 40 and the exterior of the outer
tubular member 26 through the apertures 44. In some embodiments,
the apertures 44 may only partially extend into the structure of
the outer tubular member 26, either on the interior or exterior
surface thereof. Some other embodiments may include combinations of
both complete and partial apertures 44 through the structure of the
outer tubular member 26. The shape and size of the apertures 44 can
vary, for example, to achieve the desired characteristics. For
example, the shape of apertures 44 can vary to include essentially
any appropriate shape, such as square, round, rectangular,
pill-shaped, oval, polygonal, elongate, irregular, or the like, and
may include rounded or squared edges, and can be variable in length
and width, and the like.
[0079] Additionally, the spacing, arrangement, and/or orientation
of the apertures 44, or in some embodiments, associated spines or
beams that may be formed, can be varied to achieve the desired
characteristics. For example, the number or density of the
apertures 44 along the length of the outer tubular member 26 may be
constant or may vary, depending upon the desired characteristics.
For example, the number or proximity of apertures 44 to one another
near one end of the outer member 26 may be high, while the number
or proximity of slots to one another near the other end of the
outer tubular member 26 may be relatively low and/or non existent,
or vice versa. For example, in the embodiment shown in FIGS. 1, 2,
and 3, the distal region 38 of the outer tubular member 26 includes
a plurality of apertures 44 having a relatively high density
relative to the plurality of apertures 44 located in the proximal
region 36. As such, the distal region 38 can have a greater degree
of lateral flexibility relative to the proximal region 36. The
density of the apertures 44 can vary gradually or in a stepwise
fashion over the length of the outer tubular member. And as
suggested above, certain portions of the outer tubular member 26
may not include any such apertures.
[0080] In some embodiments, the distal about 10% to about 50% of
the total length of the outer tubular member 26 can include
apertures 44 defined therein at a relatively high density, while
the proximal about 50% to about 90% of the total length of the
outer tubular member 26 include apertures 44 defined therein at a
relatively low density, and/or is free of such apertures 44. For
example, in some embodiments, the distal region 38 having a length
in the range of about 30 cm to about 70 cm includes apertures 44
defined therein at a relatively high density to provide for
relatively greater flexibility, while the remaining length in the
proximal region 36 of the outer tubular member 26 include apertures
44 defined therein at a relatively low density, and/or is free of
such apertures 44, to provide for relatively greater stiffness. It
should be understood however, that these, and other dimensions
provided herein, are by way of example embodiments only, and that
in other embodiments, the disposition of apertures 44 can vary
greatly from the dimensions given, depending upon the desired
characteristics and function of the device.
[0081] As suggested above, the apertures 44 may be formed such that
one or more spines or beams 50 are formed in the tubular outer
member 26. Such spines or beams 50 (FIG. 1) could include portions
of the tubular member 26 that remain after the apertures 44 are
formed in the body of the outer tubular member 26. Such spines or
beams 50 may act to maintain a relatively high degree of torsional
stiffness, while maintaining a desired level of lateral
flexibility. In some embodiments, some adjacent apertures 44 can be
formed such that they include portions that overlap with each other
about the circumference of the tube. In other embodiments, some
adjacent apertures 44 can be disposed such that they do not
necessarily overlap with each other, but are disposed in a pattern
that provides the desired degree of lateral flexibility.
Additionally, the apertures 44 can be arranged along the length of,
or about the circumference of, the outer tubular member 26 to
achieve desired properties. For example, the apertures 44 can be
arranged in a symmetrical pattern, such as being disposed
essentially equally on opposite sides about the circumference of
the outer tubular member 26, or equally spaced along the length of
the outer tubular member, or can be arranged in an increasing or
decreasing density pattern, or can be arranged in a non-symmetric
or irregular pattern.
[0082] Collectively, these Figures and this Description illustrate
that changes in the arrangement, number, and configuration of slots
may vary without departing from the scope of the invention. Some
additional examples of shaft constructions and/or arrangements of
cuts or slots formed in a tubular body are disclosed in U.S. Pat.
No. 6,428,489 and in published U.S. patent application Ser. Nos.
09/746,738 (Pub. No. US 2002/0013540), and 10/400,750 (Pub. No.
US-2004/0193140), all of which are incorporated herein by
reference. Also, some additional examples of shaft constructions
and/or arrangements of cuts or slots formed in a tubular body for
use in a medical device are disclosed in U.S. patent application
Ser. Nos. 10/375,493, and 10/400,750, which are also incorporated
herein by reference.
[0083] In addition to, in combination with, or as an alternative to
the structure of the outer member 26, the materials selected for
outer tubular member 26 may also be chosen so that may have the
desired characteristics. The outer tubular member 26 may be formed
of any materials suitable for use, dependent upon the desired
properties of the catheter 10. For example, outer tubular member 26
may be formed of materials having a desired modulus of elasticity,
given the structure used. Some examples of suitable materials
include metals, metal alloys, polymers, or the like, or
combinations or mixtures thereof.
[0084] Some examples of suitable metals and metal alloys include
stainless steel, such as 304V, 304L, and 316L stainless steel;
alloys including nickel-titanium alloy such as linear elastic or
superelastic (i.e., pseudoelastic) nitinol; nickel-chromium alloy;
nickel-chromium-iron alloy; cobalt alloy; tungsten or tungsten
alloys; MP35-N (having a composition of about 35% Ni, 35% Co, 20%
Cr, 9.75% Mo, a maximum 1% Fe, a maximum 1% Ti, a maximum 0.25% C,
a maximum 0.15% Mn, and a maximum 0.15% Si); hastelloy; monel 400;
inconel 625; or the like; or other suitable material, or
combinations or alloys thereof. In some embodiments, it is
desirable to use metals, or metal alloys that are suitable for
metal joining techniques such as welding, soldering, brazing,
crimping, friction fitting, adhesive bonding, etc.
[0085] Some examples of suitable polymeric materials may include,
but are not limited to: poly(L-lactide) (PLLA), poly(D,L-lactide)
(PLA), polyglycolide (PGA), poly(L-lactide-co-D,L-lactide)
(PLLA/PLA), poly(L-lactide-co-glycolide) (PLLA/PGA), poly(D,
L-lactide-co-glycolide) (PLA/PGA), poly(glycolide-co-trimethylene
carbonate) (PGA/PTMC), polyethylene oxide (PEO), polydioxanone
(PDS), polycaprolactone (PCL), polyhydroxylbutyrate (PHBT),
poly(phosphazene), polyD,L-lactide-co-caprolactone) (PLA/PCL),
poly(glycolide-co-caprolactone) (PGA/PCL), polyanhydrides (PAN),
poly(ortho esters), poly(phoshate ester), poly(amino acid),
poly(hydroxy butyrate), polyacrylate, polyacrylamid,
poly(hydroxyethyl methacrylate), polyurethane, polysiloxane and
their copolymers, or mixtures or combinations thereof. Some other
potentially suitable polymer materials may include those listed
above with reference to the inner tubular member 24.
[0086] As indicated above, some embodiments may include
linear-elastic or super-elastic nitinol in various structures
and/or components of the shaft 12 (e.g., outer tubular member 26,
inner tubular member 24, etc.). The word nitinol was coined by a
group of researchers at the United States Naval Ordinance
Laboratory (NOL) who were the first to observe the shape memory
behavior of this material. The word nitinol is an acronym including
the chemical symbol for nickel (Ni), the chemical symbol for
titanium (Ti), and an acronym identifying the Naval Ordinance
Laboratory (NOL). In some embodiments, nitinol alloys can include
in the range of about 45 to about 60 weight percent nickel, with
the remainder being essentially titanium. It should be understood,
however, that in other embodiment, the range of weight percent
nickel and titanium, and or other trace elements may vary from
these ranges. Within the family of commercially available nitinol
alloys, are categories designated as "superelastic" (i.e.,
pseudoelastic) and "linear elastic" which, although similar in
chemistry, exhibits distinct and useful mechanical properties.
[0087] In some embodiments, a superelastic alloy, for example a
superelastic nitinol, can be used to achieve desired properties.
Such alloys typically display a substantial "superelastic plateau"
or "flag region" in its stress/strain curve. Such alloys can be
desirable in some embodiments because a suitable superelastic alloy
will provide an outer member 26 that exhibits some enhanced
ability, relative to some other non-superelastic materials, of
substantially recovering its shape without significant plastic
deformation upon the application and release of stress, for
example, during placement of the catheter in the body.
[0088] In some other embodiments, a linear elastic alloy, for
example a linear elastic nitinol, can be used to achieve desired
properties. For example, in some embodiments, certain linear
elastic nitinol alloys can be generated by the application of cold
work, directional stress, and/or heat treatment, such that the
material fabricated does not display a substantial "superelastic
plateau" or "flag region" in its stress/strain curve. Instead, in
such embodiments, as recoverable strain increases, the stress
continues to increase in a somewhat linear relationship until
plastic deformation begins. In some embodiments, the linear elastic
nickel-titanium alloy is an alloy that does not show any
martensite/austenite phase changes that are detectable by DSC and
DMTA analysis over a large temperature range. For example, in some
embodiments, there are no martensite/austenite phase changes
detectable by DSC and DMTA analysis in the range of about
-60.degree. C. to about 120.degree. C. The mechanical bending
properties of such material are therefore generally inert to the
effect of temperature over a broad range of temperature. In some
particular embodiments, the mechanical properties of the alloy at
ambient or room temperature are substantially the same as the
mechanical properties at body temperature. In some embodiments, the
use of the linear elastic nickel-titanium alloy allows the outer
member to exhibit superior "pushability" around tortuous anatomy.
One example of a suitable nickel-titanium alloy exhibiting at least
some linear elastic properties is FHP-NT alloy commercially
available from Furukawa Techno Material Co. of Kanagawa, Japan.
Additionally, some examples of suitable nickel-titanium alloy
exhibiting at least some linear elastic properties include those
disclosed in U.S. Pat. Nos. 5,238,004 and 6,508,803, which are
incorporated herein by reference.
[0089] In some embodiments, the outer tubular member 26, or other
portions of the shaft 12, can be formed of a shape-memory material,
for example a shape memory alloy such as a shape memory nitinol. In
such embodiments, the shape memory effect can be used in the
deployment or use of the catheter, for example in causing the outer
tubular member 26, or other portions of the shaft 12, to move from
a first insertion configuration to a second use configuration, or,
for example, for the outer tubular member 26 to "remember" its
desired shape after deformation to another shape.
[0090] For example, in some embodiments, the outer tubular member
26 can include or be made of a shape memory alloy that is
martensite at room temperature, and has a final austenite
transition temperature (A.sub.f) somewhere in the temperature range
between room temperature and body temperature. For example, in some
such embodiments, the shape memory alloy has a final austenite
transition temperature in the range of about 25.degree. C. and
about 37.degree. C. (e.g., about body temperature). In some such
embodiments, it may be desirable that the final austenite
transition temperature be at least slightly below body temperature,
to ensure final transition at body temperature. This feature allows
the outer member 26 to be inserted into the body of a patient in a
martensitic state, and assume its preformed, austenitic shape when
exposed to the higher body temperature within the anatomy, or at
the target site. In this embodiment, deployment of the outer
tubular member 26 can be achieved by a shape memory effect; as the
material warms, it undergoes a transition from martensite to
austenite form, causing transformation of the outer tubular member
26 from the first configuration to the second configuration.
[0091] In other example embodiments, the outer tubular member 26
can include or be made of a shape-memory alloy that could have a
transition temperature M.sub.d (wherein M.sub.d=highest temperature
to strain-induced martensite) that is in the range of body
temperature (e.g., about 37.degree. C.) or greater, below which the
alloy retains sufficient stress-induced martensitic property to
allow placement of the outer tubular member 26 at or above its
final austenite transition temperature (A.sub.f). In other words,
this allows the catheter, including the outer tubular member 26 in
its preformed austenitic state, to be inserted and navigated in the
anatomy, where the outer tubular member 26 may be exposed to stress
that may promote portions thereof to undergo stress-induced
martensitic (SIM) transformation. Thereafter, the outer tubular
member 26 may recover its preformed, austenitic shape when released
from the stress of navigation, at a temperature that may be
substantially above the final austenite transition temperature
without significant plastic, or otherwise permanent deformation.
Additionally, in some such embodiments, the outer tubular member 26
can be constrained, for example, in a delivery device, such as a
guide catheter, in a stress-induced martensitic (SIM) state, and
recover its preformed, austenitic shape when released from the
constraints of the catheter, at a temperature that may be
substantially above the final austenite transition temperature
without significant plastic, or otherwise permanent deformation. In
these embodiments, the final austenite temperature may be quite
low, e.g., 4.degree. C. or lower, or it may be up to room
temperature or higher.
[0092] In yet other embodiments, the outer tubular member 26 can
include or be made of a shape memory alloy that is martensite at
body temperature, and has a final austenite transition temperature
(A.sub.f) somewhere in the temperature range above body
temperature. This feature allows the catheter including the outer
tubular member 26 to be navigated in a martensitic state, and
maintain a martensitic state until exposed to a temperature higher
than body temperature. The outer tubular member 26 can then be
heated to the necessary temperature above body temperature to make
the transformation from martensite to austenite using an external
heating means or mechanism. Such mechanisms may include the
injection of heated fluid through the catheter or other device, the
use of electrical or other energy to heat the outer tubular member
26, or other such techniques. In some such embodiments, the
shape-memory alloy has a final austenite transition temperature in
the range of about 37.degree. C. to about 45.degree. C. It may be
desirable that the final austenite transition temperature be at
least slightly above body temperature, to ensure there is not final
transition at body temperature. Some examples of Nitinol
cylindrical tubes having desired transition temperatures, as noted
above, can be prepared according to known methods.
[0093] Referring to FIG. 3, the outer tubular member 26 may be
connected to the inner tubular member 24 using any of a broad
variety of suitable techniques, some examples of which may include
adhesive bonding, friction fitting, mechanically fitting, crimping,
chemically bonding, thermally bonding, welding (e.g., resistance,
Rf, or laser welding), soldering, brazing, or the use of a
connector member or material, or the like, or combinations thereof.
As discussed above, in at least some embodiments, the outer tubular
member 26 can be disposed about the inner tubular member 24 (i.e.,
a portion of the inner tubular member 24 is disposed within the
lumen 40 of the outer member) such that a space or gap 42 is
defined between at least a portion of the outer surface 25 of the
inner tubular member 24 and the inner surface 27 of the outer
tubular member 26. In some embodiments, there may be no space
between outer tubular member 26 and inner member 24, or space or
gap 42 may be substantially filled with another member, such as
reinforcement member 31.
[0094] In FIG. 3, the outer tubular member 26 is attached to the
inner tubular member 24 at one or more proximal attachment point
53, one or more distal attachment point 59, and one or more
intermediate attachment point 61. In some embodiments, such
attachment points can be achieved, for example, using an adhesive
material, for example, a cyanoacrylate, or other suitable type of
adhesive. In at least some embodiments, only a relatively small
portion of the outer member 26 is connected to the inner tubular
member 24 at the attachment points. For example, the length of each
individual bond joint, especially at the intermediate bond joints,
may only be about 5 cm or less, or 3 cm or less, or 1 cm or less,
or 0.5 cm or less. In some embodiments, where appropriate, the
bonds extend under or within about five or fewer of the apertures
44, or three or even two or fewer of the apertures 44, along the
length of the outer tubular member. Some embodiments may include a
plurality of intermediate attachment point 61 spaced apart along
the length of the shaft 12. In some embodiments, the distance
between attachment points along the length of the shaft 12 may be
in the range of about 5 cm and about 40 cm, or in the range of
about 7 cm to about 30 cm, and may vary or be constant along the
length of the shaft 12. For example, the spacing between attachment
points may be closer together near the distal end of the shaft, and
may be farther apart near the distal portion of the shaft 12.
[0095] As indicated above, the distal portion 20 of the shaft 12
can include a distal tip 28. The distal tip 28 can be a structure,
assembly, construction and/or arrangement adapted and/or configured
to provide characteristics such as shapability, flexibility,
steerability, atraumatic characteristics, or the like, for example,
to the distal portion and/or distal end of the shaft 12. A broad
variety of distal tip constructions, configurations, and/or
structures are generally known for use on medical devices, such as
catheters, and may be used. In some embodiments, the distal tip 28
may be disposed at the distal portion 20 of the shaft 12, and may
extend distally beyond other portions of the shaft 12. In some
embodiments, distal tip 28 may extend proximally from the distal
end 22 of shaft 12 to transition region 78 of continuous wire 75.
Thus, distal tip 28 may extend over distal portion 79 of continuous
wire 75. The low profile of distal portion 79 provides distal tip
28 with a higher degree of flexibility and lower profile than
portions of elongate shaft 12 proximal of transition region 78 of
continuous wire 75.
[0096] In some embodiments, the distal tip 28 is simply one or more
portions of the shaft 12, and/or components thereof (e.g. the inner
and/or outer tubular members 24/26) that include materials and/or
structures to provide the desired characteristics. For example, in
the embodiment shown in FIG. 3, the distal tip 28 can include
and/or extend about the distal portion 20 of shaft 12 including the
inner tubular member 24. In this regard, the distal tip 28 may
include the distal portion 20 of shaft 12 including the inner
tubular member 24, and may additionally include one or more
additional layers and/or structures 52 disposed about the distal
portion 20 of shaft 12 including the inner tubular member 24. In
other embodiments, however, the distal tip 28 may include structure
and/or material that may be considered to be separate and distinct
from other portions of the shaft, but that is connected to the
distal portion of the shaft 12 to form the distal tip.
[0097] In FIG. 3, the layer 52 is disposed about the distal portion
20 of shaft 12 including the inner tubular member 24. The layers
30, 32, and 34 of the inner tubular member 24 may include distal
portions, for example 45 and 49, that include materials having
desirable flexibility characteristics, for example, as discussed
above. Additionally, the layer 52 may be made of or include any
suitable material or structure, and may be disposed by any suitable
process, the materials, structures, and processes varying with the
particular application and characteristics desired. For example, in
some embodiments, the one or more additional layers and/or
structures may include a layer of polymer or other such material,
or structures such as coils, braids, ribbons, wires, bands, or the
like.
[0098] In this embodiment, the outer layer 52 may include and/or be
made of a polymer material disposed about the distal portion 35 of
the inner tubular member 24. For example, the outer layer 52 may
include a flexible polymer material having a durometer in the range
of about 5 D to about 35 D. Some examples of suitable polymers may
include those discussed above with regard to the layers of the
inner tubular member 24, with one example being a PEBA material, or
the like. As can be appreciated, in some embodiments, the coil
layer 31, such as distal portion 79 of continuous wire 75, extends
partially into the distal tip 28, but ends and is spaced proximally
from the distal end 22. In other embodiments, however, the coil 31,
or other such reinforcing structure, or the like, may extend to the
distal end 22. Additionally, it should be understood that one or
more additional layers and/or constructions may be used in the
distal tip 28.
[0099] The outer layer 52 may be sized appropriately so as to
maintain a generally constant diameter in the transition between
the outer tubular member 26 and the outer layer 52, and may include
a portion 65 that abuts and/or overlaps the distal end 39 of the
outer tubular member 26 to provide a smooth transition.
Additionally, as in the embodiment shown, the outer tubular member
26 may include a recessed, or reduced diameter portion at the
distal end 39 thereof, and the outer layer 52 may overlap and/or
mate with the recessed portion to provide for a smooth transition.
In other embodiments, however, a tapered or step down transition
may be provided.
[0100] The outer layer 52 can be constructed and/or disposed using
any appropriate technique, for example, by extrusion, co-extrusion,
interrupted layer co-extrusion (ILC), coating, heat shrink
techniques, heat bonding, thermally bonding, casting, molding,
fusing one or several segments of an outer layer material
end-to-end, adhesive bonding, chemically bonding, crimping,
friction fitting, mechanically fitting, or the like, or
combinations thereof.
[0101] A lubricious, a hydrophilic, a protective, or other type of
coating may be applied over portions of or the entire shaft 12.
Hydrophobic coatings such as fluoropolymers provide a dry lubricity
which improves catheter handling and device exchanges. Lubricious
coatings can aid in insertion and steerability. Suitable lubricious
polymers are well known in the art and may include silicone and the
like, hydrophilic polymers such as polyarylene oxides,
polyvinylpyrolidones, polyvinylalcohols, hydroxy alkyl cellulosics,
algins, saccharides, caprolactones, and the like, and mixtures and
combinations thereof. Hydrophilic polymers may be blended among
themselves or with formulated amounts of water insoluble compounds
(including some polymers) to yield coatings with suitable
lubricity, bonding, and solubility. Some other examples of such
coatings and materials and methods used to create such coatings can
be found in U.S. Pat. Nos. 6,139,510 and 5,772,609, which are
incorporated herein by reference.
[0102] It should also be understood that in some embodiments, a
degree of MRI compatibility can be imparted into shaft 12. For
example, to enhance compatibility with Magnetic Resonance Imaging
(MRI) machines, it may be desirable to construct portions of the
outer tubular member 26, portions of the inner tubular member 24,
or other portions of the shaft 12, in a manner, or use materials,
that would impart a degree of MRI compatibility. For example, the
lengths of relatively conductive structures within the shaft 12 may
be limited to lengths that would not generate undue heat due to
resonance waves created in such structures when under the influence
of an MRI field generated by an MRI machine. Alternatively or
additionally, portions, or the entire shaft 12 may be made of a
material that does not substantially distort the image and create
substantial artifacts (artifacts are gaps in the image). Certain
ferromagnetic materials, for example, may not be suitable because
they may create artifacts in an MRI image. Additionally, all or
portions of the shaft 12, may also be made of, impregnated with,
plated or clad with, or otherwise include a material and/or
structure that the MRI machine can image. Some materials that
exhibit these characteristics include, for example, tungsten,
Elgiloy, MP35N, nitinol, and the like, and others. Additionally,
some structures including or made of such materials, such as marker
bands, marker coils, rings, impregnated polymer sections, or the
like, may be added to or included in the shaft 12. Those skilled in
the art will recognize that these materials can vary widely without
departing from the spirit of the invention.
[0103] Additionally, all or portions of the shaft 12, or components
or layers thereof, may be made of, impregnated with, plated or clad
with, or otherwise include a radiopaque material and/or structure
to facilitate radiographic visualization. Radiopaque materials are
understood to be materials capable of producing a relatively bright
image on a fluoroscopy screen or another imaging technique during a
medical procedure. This relatively bright image may aid the user of
catheter 10 in determining its location. Some examples of
radiopaque materials can include, but are not limited to, gold,
platinum, palladium, tantalum, tungsten alloy, polymer material
loaded with radiopaque filler, and the like.
[0104] For example, with reference to FIGS. 1-3, the inner tubular
member 24 can include one or more radiopaque marker member 55
disposed in the distal portion 35 between the intermediate and
outer layers 32/30, or at other positions and/or locations.
Additionally, the outer tubular member 26 can include one or more
marker members disposed thereon. In the embodiment shown, the
marker member 55 is a tubular marker band, but it should be
understood that other marker structures and arrangements, such as
marker coils, rings, impregnated polymer sections, or the like, may
be used, and may be disposed at locations along and/or within the
shaft 12. Furthermore, the elongate shaft 12, or portions thereof,
may be curved and/or shaped as desired, or be adapted and/or
configured to be curved and/or shaped as desired, depending on the
particular application.
[0105] Those skilled in the art will recognize that the present
invention may be manifested in a variety of forms other than the
specific embodiments described and contemplated herein.
Accordingly, departure in form and detail may be made without
departing from the scope and spirit of the present invention as
described in the appended claims.
* * * * *