U.S. patent application number 10/954886 was filed with the patent office on 2005-06-09 for non-compliant medical balloon having a longitudinal fiber layer.
Invention is credited to Beckham, Jim.
Application Number | 20050123702 10/954886 |
Document ID | / |
Family ID | 34636736 |
Filed Date | 2005-06-09 |
United States Patent
Application |
20050123702 |
Kind Code |
A1 |
Beckham, Jim |
June 9, 2005 |
Non-compliant medical balloon having a longitudinal fiber layer
Abstract
A non-compliant medical balloon is formed with a first fiber
layer including a first fiber and a second fiber layer over said
first fiber layer. The first fiber is substantially parallel to a
longitudinal axis of the non-compliant medical balloon.
Inventors: |
Beckham, Jim; (Athens,
TX) |
Correspondence
Address: |
HOWISON & ARNOTT, L.L.P
P.O. BOX 741715
DALLAS
TX
75374-1715
US
|
Family ID: |
34636736 |
Appl. No.: |
10/954886 |
Filed: |
September 30, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10954886 |
Sep 30, 2004 |
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10726960 |
Dec 3, 2003 |
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10954886 |
Sep 30, 2004 |
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10726464 |
Dec 3, 2003 |
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Current U.S.
Class: |
428/36.3 ;
604/103.06; 606/192 |
Current CPC
Class: |
Y10T 156/1062 20150115;
A61M 2025/1086 20130101; A61M 25/104 20130101; Y10T 428/1369
20150115; Y10T 156/1075 20150115 |
Class at
Publication: |
428/036.3 ;
606/192; 604/103.06 |
International
Class: |
B29D 022/00 |
Claims
What is claimed is:
1. A non-compliant medical balloon comprising: a first fiber layer
including a first fiber; a second fiber layer over said first fiber
layer; wherein first fiber is substantially parallel to a
longitudinal axis of said non-compliant medical balloon.
2. The non-compliant medical balloon of claim 1, wherein said first
fiber layer comprises inelastic fibers.
3. The non-compliant medical balloon of claim 1, wherein said first
fiber layer comprises a plurality of parallel first fibers.
4. The non-compliant medical balloon of claim 1, further comprising
an adhesive layer adhering to said first fiber layer.
5. The non-compliant medical balloon of claim 1, wherein said
second fiber layer comprises a plurality of parallel second
fibers.
6. The non-compliant medical balloon of claim 1, wherein the fibers
of the first fiber layer and the fibers of the second fiber layer
form an angle.
7. The non-compliant medical balloon of claim 6, wherein said angle
is substantially a right angle.
8. The non-compliant medical balloon of claim 6, wherein said angle
does not change when the balloon changes from a deflated state to
an inflated state.
9. The non-compliant medical balloon of claim 1, further comprising
a binding layer substantially coating said first fiber layer and
said second fiber layer.
10. The non-compliant medical balloon of claim 5, wherein said
plurality of parallel second fibers are substantially transverse to
the longitudinal axis of the balloon.
11. The non-compliant medical balloon of claim 10, wherein said
binding layer is a polymeric coating.
12. The non-compliant medical balloon of claim 11, wherein said
polymeric coating is formed of a polymer.
13. The non-compliant medical balloon of claim 11, wherein said
polymeric coating is formed of a copolymer.
14. The non-compliant medical balloon of claim 3, wherein said
parallel first fibers each have a thickness of about 0.0005
inch.
15. The non-compliant medical balloon of claim 5, wherein said
parallel second fibers each have a thickness of about 0.0005
inch.
16. The non-compliant medical balloon of claim 5, wherein said
parallel second fibers have a wind density of approximately 50
wraps per inch.
17. The non-compliant medical balloon of claim 6, wherein said
angle is about ten degrees.
18. The non-compliant medical balloon of claim 1, further
comprising a third fiber layer on said second fiber layer.
19. A balloon comprising: a first fiber; a second fiber over said
first fiber; wherein said first fiber is substantially parallel to
a longitudinal axis of said balloon.
20. The balloon of claim 19, wherein said first fiber is an
inelastic fiber.
21. The balloon of claim 19, further comprising a plurality of
first fibers parallel to said first fiber.
22. The balloon of claim 19, further comprising an adhesive
adhering to said first fiber.
23. The balloon of claim 19, further comprising a plurality of
second fibers parallel to said second fiber.
24. The balloon of claim 19, wherein said first fiber and said
second fiber meet at an angle.
25. The balloon of claim 24 wherein said angle is substantially a
right angle.
26. The balloon of claim 24, wherein said angle does not change
when the balloon changes from a deflated state to an inflated
state.
27. The balloon of claim 19, further comprising a binding layer
substantially coating said first fiber and said second fiber.
28. The balloon of claim 23 wherein said plurality of parallel
second fibers are substantially transverse to the longitudinal axis
of the balloon.
29. The balloon of claim 27, wherein said binding layer is a
polymeric coating.
30. The balloon of claim 29, wherein said polymeric coating is
formed of a polymer.
31. The balloon of claim 29, wherein said polymeric coating is
formed of a copolymer.
32. The balloon of claim 19, wherein said first fiber has a
thickness of about 0.0005 inch.
33. The balloon of claim 19, wherein said second fiber has a
thickness of about 0.0005 inch.
34. The balloon of claim 19, wherein said second fiber is wound
around a circumference of the balloon with a wind density of
approximately 50 wraps per inch.
35. The balloon of claim 24, wherein said angle is about ten
degrees.
36. The balloon of claim 19, further comprising a third fiber on
said second fiber.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 10/726,960, filed Dec. 3, 2003 and U.S. patent
application Ser. No. 10/726,464, filed Dec. 3, 2003.
[0002] This application is related to U.S. Pat. No. 6,746,425,
issued Jun. 8, 2004, which is a continuation-in-part of U.S. patent
application Ser. No. 08,873,413, filed Jun. 12, 1997, which claims
benefit of U.S. provisional application 60/019,931, filed Jun. 14,
1996.
FIELD OF THE INVENTION
[0003] This invention relates to the field of balloons that are
useful in angioplasty and other medical uses.
BACKGROUND OF THE INVENTION
[0004] Catheters having inflatable balloon attachments have been
used for reaching small areas of the body for medical treatments,
such as in coronary angioplasty and the like. Balloons are exposed
to large amounts of pressure. Additionally, the profile of balloons
must be small in order to be introduced into blood vessels and
other small areas of the body. Therefore, materials with high
strength relative to film thickness are chosen. An example of these
materials is PET (polyethylene terephthalate), which is useful for
providing a non-compliant, high-pressure device. Unfortunately, PET
and other materials with high strength-to-film thickness ratios
tend to be scratch- and puncture-sensitive. Polymers that tend to
be less sensitive, such as polyethylene, nylon and urethane are
compliant and, at the same film thickness as the non-compliant PET,
do not provide the strength required to withstand the pressure used
for transit in a blood vessel and expansion to open an occluded
vessel. Non-compliance, or the ability not to expand beyond a
predetermined size on pressure and to maintain substantially a
profile, is a desired characteristic for balloons so as not to
rupture or dissect the vessel as the balloon expands. Further
difficulties often arise in guiding a balloon catheter into a
desired location in a patient due to the friction between the
apparatus and the vessel through which the apparatus passes. The
result of this friction is failure of the balloon due to abrasion
and puncture during handling and use and also from
over-inflation.
SUMMARY OF THE INVENTION
[0005] The present invention is directed to a non-compliant medical
balloon suitable for angioplasty and other medical procedures and
which integrally includes very thin inelastic fibers having high
tensile strength, and methods for manufacturing the balloon. The
fiber reinforced balloons of the present invention meet the
requirements of medical balloons by providing superior burst
strength; superior abrasion-, cut- and puncture-resistence; and
superior structural integrity.
[0006] More particularly, the invention is directed to a
fiber-reinforced medical balloon having a long axis, wherein the
balloon comprises an inner polymeric wall capable of sustaining
pressure when inflated or expanded and a fiber/polymeric matrix
outer wall surrounding and reinforcing the inner polymeric wall.
The fiber/polymeric matrix outer wall is formed from at least two
layers of fibers and a polymer layer. The fibers of the first fiber
layer are substantially equal in length to the length of the long
axis of the balloon and run along the length of the long axis. But
"substantially equal in length" is meant that the fiber is at least
75% as long as the length of the long axis of the balloon, and
preferably is at least 90% as long. The fiber of the second fiber
layer runs radially around the circumference of the long axis of
the balloon substantially over the entire length of the long axis.
By "substantially over the entire length" is meant that the fiber
runs along at least the center 75% of the length of the long axis
of the balloon, and preferably runs along at least 90% of the
length. The fiber of the second fiber layer is substantially
perpendicular to the fibers of the first fiber layer. By
"substantially perpendicular to" is meant that the fiber of the
second fiber layer can be up to about 10 degrees from the
perpendicular.
[0007] The invention is further directed to processes for
manufacturing a non-compliant medical balloon. In one embodiment, a
thin layer of a polymeric solution is applied onto a mandrel, the
mandrel having the shape of a medical balloon and being removable
from the finished product. High-strength inelastic fibers are
applied to the thin layer of polymer with a first fiber layer
having fibers running substantially along the length of he long
axis of the balloon and a second fiber layer having fiber running
radially around the circumference of the long axis substantially
over the entire length of the long axis. The fibers are then coated
with a thin layer of a polymeric solution to form a fiber/polymeric
matrix. The polymers are cured and the mandrel is removed to give
the fiber-reinforced medical balloon.
[0008] In another embodiment of the invention, a polymer balloon is
inflated and is maintained in its inflated state, keeping the shape
of the balloon. High-strength inelastic fibers are applied to the
surface of the balloon, with a first fiber layer having fibers
running substantially along the length of the long axis of the
balloon and a second fiber layer having fiber running radially
around the circumference of the long axis substantially over the
entire length of the long axis. The fibers are then coated with a
thin layer of a polymeric solution to form a fiber/polymeric
matrix. The fiber/polymeric matrix is cured to give the
fiber-reinforced medical balloon, which can then be deflated for
convenience, until use.
[0009] In a presently preferred embodiment, a thin coating of an
adhesive is applied to the inflated polymer balloon or to the
polymer-coated mandrel prior to applying the inelastic fibers.
DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 illustrates an inflated standard medical balloon,
which is used in this invention as the base of the final composite
fiber-reinforced balloon.
[0011] FIG. 2 illustrates an inflated standard medical balloon,
which is used in this invention as the base of the final composite
fiber-reinforced balloon.
[0012] FIG. 3 illustrates the positioning of the second layer of
fiber over the first fiber layer. The fiber is wound radially
around the long axis substantially over the entire length of the
long axis of the balloon, each wrap being substantially equally
spaced from the others. The fiber runs substantially perpendicular
to the fibers of the first fiber layer.
[0013] FIG. 4 illustrates the positioning of the third layer of
fiber over the second fiber layer, in accordance with another
embodiment.
DETAILED DESCRIPTION OF THE INVENTION
[0014] Referring now to the drawings, wherein like reference
numbers are used to designate like elements throughout the various
views, several embodiments of the present invention are further
described. The figures are not necessarily drawn to scale, and in
some instances the drawings have been exaggerated or simplified for
illustrative purposes only. One of ordinary skill in the art will
appreciate the many possible applications and variations of the
present invention based on the following examples of possible
embodiments of the present invention.
[0015] A medical balloon in accordance with the present invention
in one embodiment begins with an inflated polymeric balloon 2, as
shown in FIG. 1, to which there is applied by hand or mechanically,
inelastic fiber or filament 4, as shown in FIG. 2. This is
sometimes referred to as the "primary wind." To assist in placement
and retention of the fibers, there can be applied an adhesive to
either the inflated balloon surface or to the fiber. The purpose of
this first application of fiber is to prevent longitudinal
extension (growth) of the completed balloon.
[0016] An alternate method of applying the longitudinal fibers
involves first creating a fabric of longitudinal fibers by pulling
taut multiple parallel fibers on a flat plate and coating with a
polymeric solution to create a fabric. The fabric is then cut into
a pattern such that it can be wrapped around the base balloon or
mandrel.
[0017] Next, a second application of inelastic fiber 6 is applied
to the circumference of the balloon, as shown in FIG. 3. This is
sometimes referred to as the "hoop wind." The purpose of the hoop
wind is to prevent or minimize distension of the completed balloon
diameter during high inflation pressures.
[0018] After the hoop wind is completed, the exterior of the
fiber-wound inflated balloon is coated with a polymeric solution
and cured to form a composite, con-complaint fiber-reinforced
medical balloon. The outer polymeric coating of the fiber/polymeric
matrix secures and bonds the fibers to the underlying inflated
balloon so that movement of the fibers is restricted during
deflation of the composite balloon and subsequent inflation and
deflation during use of the balloon. The polymeric solution can be
applied several times, if desired. The polymeric solution can use
the same polymer as or a polymer different from the polymer of the
inflated polymeric balloon 2. The polymers should be compatible so
that separation of the composite balloon is prevented or
minimized.
[0019] In a second method of making a medical balloon of the
present invention, a removable mandrel having the shape that is
identical to the shape of the inside of the desired balloon is
used. A shape such as shown in FIG. 1 is suitable. The mandrel can
be made of collapsible metal or polymeric bladder, foams, waxes,
low-melting metal alloys, and the like. The mandrel is first coated
with a layer of a polymer, which is then cured. This forms the
inner polymeric wall of the balloon. Next, repeating the steps as
described above, the primary wind and the hoop wind are placed over
the inner polymer wall, followed by a coating with a polymeric
solution and curing thereof to form a fiber/polymeric matrix outer
wall. Finally, the mandrel is removed, by methods known in the art
such as by mechanical action, by solvent, or by temperature change,
to give the composite medical balloon of the invention.
[0020] In view of the high strength of the balloons of the present
invention, it is possible to make balloons having a wall thickness
less than conventional or prior art balloons without sacrifice of
burst strength, abrasion resistance, or puncture resistance. The
balloon wall thickness can be less than the thickness given in the
examples hereinbelow.
[0021] In addition, the fiber-reinforced balloons of the present
invention are non-compliant. That is, they are characterized by
minimal axial stretch and minimal radial distention and by the
ability not to expand beyond a predetermined size on pressure and
to maintain substantially a profile.
[0022] Polymers and copolymers that can be used for the base
balloon and/or the covering layer of the fiber/polymeric matrix
include the conventional polymers and copolymers used in medical
balloon construction, such as, but not limited to, polyethylene,
polyethylene terephthalate (PET), polycaprolactam, polyesters,
polyethers, polyamides, polyurethanes, polyimides, ABS copolymers,
polyester/polyether block copolymers, ionomer resins, liquid
crystal polymers, and rigid rod polymers.
[0023] The high-strength fibers are chosen to be inelastic. By
"inelastic," as used herein and in the appended claims, is meant
that the fibers have very minimal elasticity or stretch. Zero
elasticity or stretch is probably unobtainable taking into account
the sensitivity of modem precision test and measurement
instruments, affordable costs and other factors. Therefore, the
term "inelastic" should be understood to mean fibers that are
generally classified as inelastic but which, nevertheless, may have
a detectable, but minimal elasticity or stretch. High strength
inelastic fibers useful in the present invention include but are
not limited to, Kevlar, Vectran, Spectra, Dacron, Dyneema, Terlon
(PBT), Zylon (PBO), Polyimide (PIM), ultra high molecular weight
polyethylene, and the like. In a presently preferred embodiment,
the fibers are ribbon-like; that is, they have a flattened to a
rectangular shape. The fibers of the first fiber layer may be the
same as or different from the fiber of the second fiber layer.
[0024] The most advantageous density of the fiber wind is
determinable through routine experimentation by one of ordinary
skill in the art given the examples and guidelines herein. With
respect to the longitudinally-placed fibers (along the long axis of
the balloon) of the first fiber layer, generally about 15 to 30
fibers having a fiber thickness of about 0.0005 to 0.001 inch and
placed equidistant from one another will provide adequate strength
for a standard-sized medical balloon. With respect to the fiber of
the hoop wind, or second fiber layer, fiber having a thickness of
about 0.0005 to 0.001 inch and a wind density within the range of
about 50 to 80 wraps per inch is generally adequate. The fiber of
the second fiber layer is preferably continuous and is, for a
standard-sized medical balloon, about 75-100 inches long.
[0025] The longitudinally placed fibers should be generally
parallel to or substantially parallel to the long axis of the
balloon for maximum longitudinal stability (non-stretch) of the
balloon. The fibers of the hoop wind should be perpendicular to or
substantially perpendicular to the fibers placed longitudinally for
maximum radial stability (non-stretch) of the balloon. This
distributes the force on the balloon surface equally and creates
"pixels" of equal shape and size. In the case where the fibers of
the hoop wind are at a small acute angle (e.g. about 10 degrees or
more) to the longitudinal fibers, two hoop winds (in opposite
directions) can be used for minimizing radial distension. FIG. 4
depicts a balloon having a second hoop wind 12.
EXAMPLES
[0026] The following examples are provided to illustrate the
practice of the present invention, and are intended neither to
define nor to limit the scope of the invention in any manner.
Example 1
[0027] An angioplasty balloon, as shown in FIG. 1, having a wall
thickness of 0.0008 inch is inflated to about 100 psi, and the two
open ends of the balloon are closed off. The inflation pressure
maintains the shape (geometry) of the balloon in an inflated
profile during the construction of the composite balloon. The
balloon is a blow-molded balloon of highly oriented polyethylene
terephthalate (PET). To the inflated balloon is applied a very thin
coat of 3M-75 adhesive to hold the fibers sufficiently to prevent
them from slipping out of position after placement on the
balloon.
[0028] Kevlar.RTM. fibers are placed, by hand, along the length of
the balloon as shown in FIG. 2 to provide the primary wind. Each of
the fibers is substantially equal in length to the length of the
long axis of the balloon. Twenty-four fibers are used,
substantially equally spaced from each other. The fiber used for
the primary wind has a thickness of 0.0006 inch.
[0029] Next, a hoop wind of Kevlar.RTM. fiber is applied radially
around the circumference of and over substantially the entire
length of the long axis of the balloon, as shown in FIG. 3. The
fiber has a thickness of 0.0006 inch and is applied at a wind
density of 60 wraps per inch.
[0030] The fiber-wound based PET balloon is then coated with a 10%
solution of Texin.RTM. 5265 polyurethane in dimethylacetamide (DMA)
and allowed to cure at room temperature. Five additional coating of
the polurethane solution are applied in about 6-hour increments,
after which the pressure in the balloon is released. The resulting
composite fiber-reinforced balloon is non-compliant and exhibits
superior burst strength and abrasion and puncture resistance.
[0031] 3M-75 is a tacky adhesive available from the 3M Company,
Minneapolis, Minn. Kevlar.RTM. is a high strength, inelastic fiber
available from the DuPont Company, Wilmington Del. Texin.RTM. 5265
is a polyurethane polymer available from Miles, Inc., Pittsburgh,
Pa.
Example 2
[0032] The procedure of Example 1 was repeated with the exception
that Vectran.RTM. fiber, having a thickness of 0.0005 inch is used
in place of the Kevlar.RTM. fiber. The resulting composite balloon
is axially and radially non-compliant at very high working
pressures. The balloon has very high tensile strength and abrasion
and puncture resistance.
[0033] Vectran.RTM. is a high strength fiber available from
Hoechst-Celanese, Charlotte, N.C.
Example 3
[0034] A mandrel in the shape of a balloon as shown in FIG. 1 is
made of a water-soluble wax. The wax mandrel is coated with a very
thin layer (0.0002 inch) of Texin.RTM. 5265 polyurethane. After
curing, adhesive and Vectran.RTM. fibers are applied, following the
procedure of Example 1. Next, several coats of Texin.RTM. 5265
polyurethane as applied in Example 1. The wax is then exhausted by
dissolving in hot water to give a non-compliant, very high
strength, abrasion-resistant, composite fiber-reinforced
balloon.
Example 4
[0035] The procedure of Example 3 is repeated using high strength
Spectra.RTM. fiber in place of Vectran.RTM. fiber. Spectra.RTM.
fiber is available from Allied Signal, Inc., Morristown, N.J.
Example 5
[0036] The procedure of Example 1 is repeated using Ultra High
Molecular Weight Polyethylene (Spectra 2000) fiber, which has been
flattened on a roll mill. To the flattened fiber is applied a thin
coat of a solution of 1-MP Tecoflex.RTM. adhesive in a 60-40
solution of methylene chloride and methylethylketone. The fiber is
applied to the balloon as in Example 1 using 30 longitudinal
fibers, each substantially equal in length to the length of the
long axis of the balloon, and a hoop wind of 54 wraps per inch. The
fibers are then coated with the Tecoflex.RTM. solution.
[0037] Tecoflex.RTM. is supplied by Thermedics Inc., Woburn,
Mass.
Example 6
[0038] A balloon-shaped solid mandrel made of a low melting
temperature metal alloy is coated with a thin layer of Texin.RTM.
5265/DMA solution (10%). Vectran.RTM. fibers are applied as in
Example 1, followed by coating with Texin.RTM./DMA. The metal
mandrel is melted out using hot water. A very high strength,
abrasion-resistant, composite balloon is obtained, which is
non-compliant.
Example 7
[0039] Following the procedures of Example 6, a mandrel is coated
with a very thin layer of PIM polyimide (2,2-dimethylbenzidine) in
solution in cyclopentanone. Polyimide fibers are applied, and the
composite balloon is then completed with additional applications of
the PIM solution. The mandrel is removed to give a high strength,
puncture-resistant balloon having an extremely cohesive
fiber/matrix composite wall that is resistant to delarnination.
Example 8
[0040] A balloon is constructed as in Example 7, except that the
longitudinal fibers are replaced by a longitudinally oriented thin
film made of polyimide LARC-IA film (available from IMITEC,
Schenectady, N.Y.). The film is cut into a mandrel-shaped pattern
and applied to the mandrel, over which the polyimide hoop fibers
and the PIM solution are applied.
[0041] Although the illustrative embodiment has been described in
detail, it should be understood that various changes, substitutions
and alterations can be made therein without departing from the
spirit and scope of the invention as defined by the appended
claims.
* * * * *