U.S. patent application number 17/673221 was filed with the patent office on 2022-08-11 for optical assemblies to improve energy coupling to pressure wave generator of an intravascular lithotripsy device.
The applicant listed for this patent is Bolt Medical, Inc.. Invention is credited to Christopher A. Cook, Itzhak Fang, Jennet Johnson, George Liu, Mina Mossayebi, Eric Schultheis, Theresa Shar.
Application Number | 20220249166 17/673221 |
Document ID | / |
Family ID | |
Filed Date | 2022-08-11 |
United States Patent
Application |
20220249166 |
Kind Code |
A1 |
Cook; Christopher A. ; et
al. |
August 11, 2022 |
OPTICAL ASSEMBLIES TO IMPROVE ENERGY COUPLING TO PRESSURE WAVE
GENERATOR OF AN INTRAVASCULAR LITHOTRIPSY DEVICE
Abstract
A method for treating a treatment site (106) within or adjacent
to a vessel wall (108) or heart valve includes tapering an optical
fiber (122) from a fiber proximal end (122P) to a fiber distal end
(122D); positioning the optical fiber (122) such that the fiber
distal end (122D) is positioned within an inflatable balloon (104);
coupling an energy source (124) in optical communication with the
fiber proximal end (122P); and receiving an energy pulse from the
energy source (124) into the fiber proximal end (122P) so that the
optical fiber (122) emits light energy in a direction away from the
optical fiber (122) to generate a plasma pulse within the
inflatable balloon (104). The method can further include coupling a
first fiber member (250) to a second fiber member (258), which can
include fusing the first fiber member (250) to the second fiber
member (258) at a fused region (256); and encircling the fused
region (256) with a ferrule (248).
Inventors: |
Cook; Christopher A.;
(Laguna Niguel, CA) ; Schultheis; Eric; (San
Clemente, CA) ; Mossayebi; Mina; (Irvine, CA)
; Liu; George; (Irvine, CA) ; Fang; Itzhak;
(Irvine, CA) ; Johnson; Jennet; (Fallbrook,
CA) ; Shar; Theresa; (San Diego, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Bolt Medical, Inc. |
Carlsbad |
CA |
US |
|
|
Appl. No.: |
17/673221 |
Filed: |
February 16, 2022 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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17666172 |
Feb 7, 2022 |
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17673221 |
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63148133 |
Feb 10, 2021 |
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International
Class: |
A61B 18/26 20060101
A61B018/26 |
Claims
1. A method for treating a treatment site within or adjacent to a
vessel wall or a heart valve, the method comprising the steps of:
tapering an optical fiber from a fiber proximal end to a fiber
distal end; positioning the optical fiber such that the fiber
distal end is positioned within an inflatable balloon; coupling an
energy source in optical communication with the fiber proximal end
of the optical fiber; and receiving an energy pulse from the energy
source into the fiber proximal end of the optical fiber so that the
optical fiber emits light energy in a direction away from the
optical fiber to generate a plasma pulse within the inflatable
balloon.
2. The method of claim 1 wherein the step of tapering includes
tapering the optical fiber using a fusion splicer.
3. The method of claim 1 further comprising the step of splicing
the optical fiber using a core matched fiber.
4. The method of claim 1 further comprising the step of coupling a
first fiber member of the optical fiber to a second fiber member of
the optical fiber.
5. The method of claim 4 wherein the step of positioning includes
positioning the second fiber member within the inflatable
balloon.
6. The method of claim 4 wherein the step of coupling the first
fiber member of the optical fiber to the second fiber member of the
optical fiber includes fusing the first fiber member to the second
fiber member at a fused region.
7. The method of claim 6 further comprising the step of encircling
the fused region with a ferrule.
8. The method of claim 7 wherein the step of encircling includes
the ferrule having an outer diameter of 1.25 mm LC ferrules.
9. The method of claim 7 wherein the step of encircling includes
the ferrule having an outer diameter of 2.5 mm SC ferrules.
10. The method of claim 7 wherein the step of encircling includes
the ferrule being formed from one of a plastic and a metal.
11. The method of claim 7 wherein the step of encircling includes
encircling only one optical fiber with the ferrule.
12. The method of claim 7 wherein the step of encircling includes
the ferrule being one of a multi-fiber MT ferrule and an MTP
ferrule.
13. The method of claim 4 wherein the step of coupling the first
fiber member of the optical fiber to the second fiber member of the
optical fiber includes forming the first fiber member and the
second fiber member as a unitary structure.
14. The method of claim 4 wherein the step of positioning includes
positioning a first fiber member distal region of the first fiber
member outside of the inflatable balloon.
15. The method of claim 4 wherein the step of positioning includes
positioning a second fiber member proximal region of the second
fiber member outside of the inflatable balloon.
16. The method of claim 4 wherein the step of coupling the first
fiber member of the optical fiber to the second fiber member of the
optical fiber includes the first fiber member including an
endcap.
17. The method of claim 1 wherein the step of tapering includes
tapering the optical fiber from a diameter of at least 150 .mu.m
down to a diameter of less than 120 .mu.m.
18. The method of claim 1 wherein the step of tapering includes the
optical fiber having a tapered portion with a tapered portion
length of at least 2 mm.
19. The method of claim 1 wherein the step of coupling the energy
source includes the energy source including a laser.
20. A method for treating a treatment site within or adjacent to a
vessel wall or a heart valve, the method comprising the steps of:
fusing a first fiber member of an optical fiber to a second fiber
member of the optical fiber to define a fused region of the optical
fiber, the optical fiber having a fiber proximal end and a fiber
distal end; substantially encircling at least the fused region of
the optical fiber with a ferrule; positioning the optical fiber
such that the fiber distal end is positioned within an inflatable
balloon; coupling a laser in optical communication with the fiber
proximal end of the optical fiber; and receiving an energy pulse
from the laser into the fiber proximal end of the optical fiber so
that the optical fiber emits light energy in a direction away from
the optical fiber to generate a plasma pulse within the inflatable
balloon.
Description
RELATED APPLICATIONS
[0001] This application is a Continuation Application and claims
the benefit under 35 U.S.C. 120 on co-pending U.S. patent
application Ser. No. 17/666,172, filed on Feb. 7, 2022, and
entitled "OPTICAL ASSEMBLIES TO IMPROVE ENERGY COUPLING TO PRESSURE
WAVE GENERATOR OF AN INTRAVASCULAR LITHOTRIPSY DEVICE".
Additionally, U.S. patent application Ser. No. 17/666,172 claims
priority from U.S. Provisional Patent Application Ser. No.
63/148,133, entitled "OPTICAL ASSEMBLIES TO IMPROVE ENERGY COUPLING
TO PRESSURE WAVE GENERATOR OF AN INTRAVASCULAR LITHOTRIPSY DEVICE",
filed on Feb. 10, 2021. To the extent permitted, the contents of
U.S. patent application Ser. No. 17/666,172 and U.S. Provisional
Patent Application Ser. No. 63/148,133 are incorporated in their
entirety herein by reference.
BACKGROUND
[0002] Vascular lesions within and adjacent to vessels in the body
can be associated with an increased risk for major adverse events,
such as myocardial infarction, embolism, deep vein thrombosis,
stroke, and the like. Severe vascular lesions can be difficult to
treat and achieve patency for a physician in a clinical
setting.
[0003] Vascular lesions may be treated using interventions such as
drug therapy, balloon angioplasty, atherectomy, stent placement,
vascular graft bypass, to name a few. Such interventions may not
always be ideal or may require subsequent treatment to address the
lesion.
[0004] Using optical fiber delivery of laser pulses to generate
high-pressure impulses on the lesions is one way to attempt to
treat the lesions. The creation of plasma via optical breakdown of
an aqueous solution typically requires a significant amount of
energy in a short amount of time upon which it is converted into a
therapeutic bubble and/or a therapeutic pressure wave.
SUMMARY
[0005] The present invention is directed toward a catheter system
for treating a treatment site within or adjacent to a vessel wall
or a heart valve. The catheter system includes an inflatable
balloon, an optical fiber, and an energy source. In certain
embodiments, the optical fiber has (i) a fiber proximal end and
(ii) a fiber distal end positioned within the inflatable balloon.
The optical fiber can be configured to receive an energy pulse so
that the optical fiber emits light energy in a direction away from
the optical fiber to generate a plasma pulse within the inflatable
balloon, the optical fiber being tapered from the fiber proximal
end to the fiber distal end. The energy source can be in optical
communication with the fiber proximal end of the optical fiber.
[0006] In various embodiments, the optical fiber can be tapered
using a fusion splicer.
[0007] In certain embodiments, the optical fiber can be spliced
using a core matched fiber.
[0008] In some embodiments, the optical fiber can be split into a
first fiber member and a second fiber member.
[0009] In various embodiments, the optical fiber can be split so
that only the second fiber member can be positioned within the
inflatable balloon.
[0010] In certain embodiments, the second fiber member can include
a plurality of second fiber legs.
[0011] In some embodiments, the second fiber member can include two
second fiber legs.
[0012] In various embodiments, the second fiber member can include
three second fiber legs.
[0013] In certain embodiments, the first fiber member can be fused
to the second fiber member in a fused region.
[0014] In some embodiments, the first fiber member and the second
fiber member are formed as a unitary structure.
[0015] In various embodiments, the first fiber member and the
second fiber member are integrally formed with one another.
[0016] In certain embodiments, the first fiber member and the
second fiber member are continuously formed as a single
structure.
[0017] In some embodiments, the first fiber member can have a first
fiber member distal region that is outside the inflatable
balloon.
[0018] In various embodiments, the second fiber member can have a
second fiber member proximal region that is outside the inflatable
balloon.
[0019] In certain embodiments, the first fiber member distal region
can be fused to the second fiber member proximal region in the
fused region.
[0020] In some embodiments, the energy source can include a
laser.
[0021] In various embodiments, the catheter system can include a
ferrule that encircles the fused region.
[0022] In certain embodiments, the catheter system can include a
ferrule that encircles a first fiber proximal end of the first
optical fiber and the first fiber distal end of the second
fiber.
[0023] In some embodiments, the catheter system can include a
plurality of ferrules that encircle portions of the first fiber
member and the second fiber member.
[0024] In various embodiments, the ferrule can have an outer
diameter of 1.25 mm LC ferrules.
[0025] In certain embodiments, the ferrule can have an outer
diameter of 2.5 mm SC ferrules.
[0026] In some embodiments, the ferrule can be formed by one of a
plastic and a metal.
[0027] In various embodiments, the ferrule can be configured for
only one optical fiber.
[0028] In certain embodiments, the ferrule can be configured for a
plurality of fiber members.
[0029] In some embodiments, the ferrule can be one of a multi-fiber
MT ferrule and an MTP ferrule.
[0030] In various embodiments, the optical fiber can be cleaved at
a first tapered portion of the first fiber member.
[0031] In certain embodiments, the optical fiber can be cleaved by
one of a laser cleaver and a mechanical cleaver.
[0032] In some embodiments, the first fiber member can have a first
cleaved portion that can be cleaved a second time to form a curved
ball surface.
[0033] In various embodiments, the optical fiber can be tapered
with rotation.
[0034] In certain embodiments, the optical fiber can be tapered
without rotation.
[0035] In some embodiments, the ferrule can include at least one of
a tapered fiber, a spliced joint, and a bare fiber.
[0036] In various embodiments, at least one of the tapered fiber,
the spliced joint, and the bare fiber are retained inside the
ferrule with an epoxy.
[0037] In certain embodiments, the epoxy can be ND353 encircled for
fiber connector polishing.
[0038] In some embodiments, the epoxy can be LOCTITE.RTM. 4310 UV
adhesive. In various embodiments, the optical fiber can be tapered
from a diameter of 200 .mu.m to a diameter of 105 .mu.m.
[0039] In certain embodiments, the optical fiber can be configured
to split a light energy traveling through the first fiber member
into the second fiber member.
[0040] In some embodiments, the first fiber member can include an
endcap.
[0041] In various embodiments, the ferrule substantially surrounds
the first fiber member.
[0042] In certain embodiments, the optical fiber can be tapered so
that it can have a greater diameter on the fiber proximal end and a
lesser diameter on the fiber distal end.
[0043] The present invention is also directed toward a method for
manufacturing the catheter system.
[0044] The present invention is further directed toward a method
for treating a treatment site within or adjacent to a vessel wall
or heart valve. The method can include the steps of positioning an
optical fiber having (i) a fiber proximal end and (ii) a fiber
distal end positioned within the inflatable balloon, the optical
fiber being configured to receive an energy pulse so that the
optical fiber emits light energy in a direction away from the
optical fiber to generate a plasma pulse within the inflatable
balloon, and coupling an energy source with the fiber proximal end
of the optical fiber so that the energy source is in optical
communication with the optical fiber.
[0045] In some embodiments, the method can include the step of
tapering the optical fiber using a fusion splicer.
[0046] In various embodiments, the method can include the step of
splicing the optical fiber using a core matched fiber.
[0047] In certain embodiments, the method can include the step of
encircling the fused region using a ferrule.
[0048] In some embodiments, the method can include the step of
encircling a first fiber distal end of the first fiber member and
the second fiber proximal end of the second fiber member using a
ferrule.
[0049] In various embodiments, the method can include the step of
encircling portions of the first fiber member and the second fiber
member using a plurality of ferrules.
[0050] The present invention is also directed toward a catheter
system that includes an inflatable balloon, an optical fiber, an
energy source, and a fused region. The optical fiber can have (i) a
fiber proximal end and (ii) a fiber distal end positioned within
the inflatable balloon. The optical fiber can be configured to
receive an energy pulse so that the optical fiber emits light
energy in a direction away from the optical fiber to generate a
plasma pulse within the inflatable balloon. The optical fiber can
include a first fiber member and a second fiber member. The energy
source can be in optical communication with the fiber proximal end
of the optical fiber. The fused region can be located where the
first fiber member is fused to the second fiber member.
[0051] The present invention is further directed toward a catheter
system that includes an inflatable balloon, an optical fiber, an
energy source, and a fused region. The optical fiber can have (i) a
fiber proximal end and (ii) a fiber distal end positioned within
the inflatable balloon. The optical fiber can be configured to
receive an energy pulse so that the optical fiber emits light
energy in a direction away from the optical fiber to generate a
plasma pulse within the inflatable balloon. The optical fiber can
have a first fiber member and a second fiber member including a
plurality of second fiber member legs. The energy source can be in
optical communication with the fiber proximal end of the optical
fiber.
[0052] The fused region can be located where the first fiber member
is fused to the second fiber member. The fused region can be
configured to split the light energy traveling through the first
fiber member into the second fiber member so that the light energy
is split between the plurality of the second fiber member legs.
[0053] The present invention is also directed toward a catheter
system that includes an inflatable balloon, an optical fiber, an
energy source, a fused region, and a capillary. The optical fiber
can have (i) a fiber proximal end and (ii) a fiber distal end
positioned within the inflatable balloon. The optical fiber can be
configured to receive an energy pulse so that the optical fiber
emits light energy in a direction away from the optical fiber to
generate a plasma pulse within the inflatable balloon. The optical
fiber can have a first fiber member and a second fiber member
including a plurality of second fiber member legs. The energy
source can be in optical communication with the fiber proximal end
of the optical fiber. The fused region can be located where the
first fiber member is fused to the second fiber member. The fused
region can be configured to split the light energy traveling
through the first fiber member into the second fiber member so that
the light energy is split between the plurality of the second fiber
member legs. The capillary can substantially surround the fused
region.
[0054] The present invention is further directed toward a catheter
system that includes an inflatable balloon, an optical fiber, a
fused region, and a ferrule. The optical fiber can have (i) a fiber
proximal end and (ii) a fiber distal end positioned within the
inflatable balloon. The optical fiber can be configured to receive
an energy pulse so that the optical fiber emits light energy in a
direction away from the optical fiber to generate a plasma pulse
within the inflatable balloon. The optical fiber can include an
endcap and a first fiber distal end positioned within the
inflatable balloon. The optical fiber can have a first fiber member
and a second fiber member. The fused region can be located where
the first fiber member is fused to the second fiber member. The
ferrule can substantially surround the fused region.
[0055] The present invention is also directed toward a catheter
system that includes an inflatable balloon, an optical fiber, an
energy source, a fused region, and a ferrule. The optical fiber can
have (i) a fiber proximal end, and (ii) a fiber distal end
positioned within the inflatable balloon. The optical fiber can be
configured to receive an energy pulse so that the optical fiber
emits light energy in a direction away from the optical fiber to
generate a plasma pulse within the inflatable balloon. The optical
fiber can include a first fiber member and a second fiber member.
The energy source can be in optical communication with the fiber
proximal end of the optical fiber. The fused region can be located
where the first fiber member is fused to the second fiber member.
The ferrule can substantially surround the first fiber member and
the fused region.
[0056] The present invention is further directed toward a catheter
system that includes an inflatable balloon and an optical fiber.
The optical fiber can have (i) a fiber proximal end, and (ii) a
fiber distal end positioned within the inflatable balloon. The
optical fiber can be configured to receive an energy pulse so that
the optical fiber emits light energy in a direction toward the
fiber distal end to generate a plasma pulse within the inflatable
balloon. The optical fiber can be tapered so that it can have a
greater diameter on the fiber proximal end and a lesser diameter on
the fiber distal end.
[0057] The present invention is also directed toward a catheter
system that includes an inflatable balloon and an optical fiber.
The optical fiber can have (i) a fiber proximal end, and (ii) a
fiber distal end positioned within the inflatable balloon. The
optical fiber can be configured to receive an energy pulse so that
the optical fiber emits light energy in a direction away from the
optical fiber to generate a plasma pulse within the inflatable
balloon. The optical fiber can be tapered from the fiber proximal
end to the fiber distal end. The energy source can be in optical
communication with the fiber proximal end of the optical fiber.
[0058] The present invention is further directed toward a catheter
system that includes an inflatable balloon and an optical fiber.
The optical fiber can have (i) a fiber proximal end, and (ii) a
fiber distal end positioned within the inflatable balloon. The
optical fiber can be configured to receive an energy pulse so that
the optical fiber emits light energy in a direction away from the
optical fiber to generate a plasma pulse within the inflatable
balloon. The optical fiber can be split into a plurality of fiber
members positioned within the inflatable balloon. The energy source
can be in optical communication with the fiber proximal end of the
optical fiber.
[0059] In various embodiments, the optical fiber can be tapered
from a diameter of 220 .mu.m to a diameter of 100 .mu.m.
[0060] In some embodiments, the optical fiber can be tapered from
(i) an initial diameter to (ii) a final diameter having a diameter
of 90% to 10% of the initial diameter.
[0061] In certain embodiments, the catheter system can include a
third fiber member and a second fused region, the third fiber
member being fused to the second fiber member in the second fused
region, the second fiber member further including a second tapered
portion.
[0062] The present invention is also directed toward a catheter
system for treating a treatment site within or adjacent to a vessel
wall or heart valve. The catheter system can include an inflatable
balloon, an optical fiber, an energy source, a first tapered
portion, a second tapered portion, a first fused region, a second
fused region, and a ferrule. The optical fiber can have (i) a fiber
proximal end, and (ii) a fiber distal end positioned within the
inflatable balloon, the optical fiber being configured to receive
an energy pulse so that the optical fiber emits light energy in a
direction away from the optical fiber to generate a plasma pulse
within the inflatable balloon, the optical fiber having a first
fiber member, a second fiber member, and a third fiber member. The
energy source can be optical communication with the fiber proximal
end of the optical fiber. The first tapered portion can be located
on the first fiber member. The second tapered portion can be
located on the second fiber member. The first fused region where
the first fiber member is fused to the second fiber member. The
second fused region can be where the second fiber member is fused
to the third fiber member. The ferrule can substantially surround
the first fiber member and the first fused region.
[0063] This summary is an overview of some of the teachings of the
present application and is not intended to be an exclusive or
exhaustive treatment of the present subject matter. Further details
are found in the detailed description and appended claims. Other
aspects will be apparent to persons skilled in the art upon reading
and understanding the following detailed description and viewing
the drawings that form a part thereof, each of which is not to be
taken in a limiting sense. The scope herein is defined by the
appended claims and their legal equivalents.
BRIEF DESCRIPTION OF THE DRAWINGS
[0064] The novel features of this invention, as well as the
invention itself, both as to its structure and its operation, will
be best understood from the accompanying drawings, taken in
conjunction with the accompanying description, in which similar
reference characters refer to similar parts, and in which:
[0065] FIG. 1 is a schematic cross-sectional view of one embodiment
of a catheter system having features of the present invention;
[0066] FIG. 2 is a schematic cross-sectional view of one embodiment
of a portion of the catheter system including an optical fiber,
coupling optics, and an energy source;
[0067] FIG. 3A is a schematic cross-sectional view of one
embodiment of a portion of the catheter system including an
embodiment of the optical fiber;
[0068] FIG. 3B is a schematic cross-sectional view of another
embodiment of another optical fiber for use within a catheter
system;
[0069] FIG. 3AA is a cross-sectional view of the optical fiber
taken on line 3AA-3AA in FIG. 3A;
[0070] FIG. 3BB is a cross-sectional view of the optical fiber
taken on line 3BB-3BB in FIG. 3B;
[0071] FIG. 4A is a schematic cross-sectional view of another
embodiment of the catheter system including an embodiment of the
optical fiber, the coupling optics, and the energy source; and
[0072] FIG. 4B is a schematic cross-sectional view of another
embodiment of the catheter system including another embodiment of
the optical fiber, the coupling optics, and the energy source.
[0073] While embodiments are susceptible to various modifications
and alternative forms, specifics thereof have been shown by way of
example and drawings, and will be described in detail. It should be
understood, however, that the scope herein is not limited to the
particular aspects described. On the contrary, the intention is to
cover modifications, equivalents, and alternatives falling within
the spirit and scope herein.
DESCRIPTION
[0074] Treatment of vascular lesions can reduce major adverse
events or death in affected subjects. A major adverse event is one
that can occur anywhere within the body due to the presence of a
vascular lesion. Major adverse events can include, but are not
limited to major adverse cardiac events, major adverse events in
the peripheral or central vasculature, major adverse events in the
brain, major adverse events in the musculature, or major adverse
events in any of the internal organs.
[0075] As used herein, the treatment site can include a vascular
lesion such as a calcified vascular lesion or a fibrous vascular
lesion (hereinafter sometimes referred to simply as a "lesion" or
"treatment site"), typically found in a blood vessel and/or a heart
valve. Plasma formation can initiate a pressure wave and can
initiate the rapid formation of one or more bubbles that can
rapidly expand to a maximum size and then dissipate through a
cavitation event that can also launch a pressure wave upon
collapse. The rapid expansion of the plasma-induced bubbles can
generate one or more pressure waves within a balloon fluid and
thereby impart pressure waves upon the treatment site. The pressure
waves can transfer mechanical energy through an incompressible
balloon fluid to a treatment site to impart a fracture force on the
lesion. Without wishing to be bound by any particular theory, it is
believed that the rapid change in balloon fluid momentum upon a
balloon wall of the inflatable balloon that is in contact with or
positioned near the lesion is transferred to the lesion to induce
fractures in the lesion.
[0076] Those of ordinary skill in the art will realize that the
following detailed description of the present invention is
illustrative only and is not intended to be in any way limiting.
Other embodiments of the present invention will readily suggest
themselves to such skilled persons having the benefit of this
disclosure. Additionally, other methods of delivering energy to the
lesion can be utilized, including, but not limited to, the electric
current induced plasma generation. Reference will now be made in
detail to implementations of the present invention as illustrated
in the accompanying drawings.
[0077] In the interest of clarity, not all of the routine features
of the implementations described herein are shown and described. It
will, of course, be appreciated that in the development of any such
actual implementation, numerous implementation-specific decisions
must be made in order to achieve the developer's specific goals,
such as compliance with application-related and business-related
constraints, and that these specific goals will vary from one
implementation to another and from one developer to another.
Moreover, it is appreciated that such a development effort might be
complex and time-consuming, but would nevertheless be a routine
undertaking of engineering for those of ordinary skill in the art
having the benefit of this disclosure.
[0078] As used herein, the terms "treatment site", "intravascular
lesion" and "vascular lesion" are used interchangeably unless
otherwise noted and can include lesions located at or near blood
vessels or heart valves.
[0079] It is appreciated that the catheter systems herein can
include many different forms and/or configurations other than those
specifically shown and/or described herein. Referring now to FIG.
1, a schematic cross-sectional view is shown of a catheter system
in accordance with various embodiments herein. A catheter system
100 is suitable for imparting pressure to induce fractures in a
vascular lesion within or adjacent to a vessel wall of a blood
vessel and/or a heart valve. In the embodiment illustrated in FIG.
1, the catheter system 100 can include one or more of a catheter
102, one or more optical fibers 122, a controller 123, an energy
source 124, a manifold 136, a fluid pump 138, and a multiplexer
(not shown).
[0080] The catheter 102 includes an inflatable balloon 104
(sometimes referred to herein as "balloon"). The catheter 102 is
configured to move to a treatment site 106 within or adjacent to a
blood vessel 108. The treatment site 106 can include a vascular
lesion such as a calcified vascular lesion, for example.
Additionally, or in the alternative, the treatment site 106 can
include a vascular lesion such as a fibrous vascular lesion.
[0081] The catheter 102 can include the balloon 104, a catheter
shaft 110, and a guidewire 112. The balloon can be coupled to the
catheter shaft 110. The balloon can include a balloon proximal end
104P and a balloon distal end 104D. The catheter shaft 110 can
extend between a shaft proximal end 114 and a shaft distal end 116.
The catheter shaft 110 can include a guidewire lumen 118 which is
configured to move over the guidewire 112. The catheter shaft 110
can also include an inflation lumen (not shown). In some
embodiments, the catheter 102 can have a distal end opening 120 and
can accommodate and be moved over and/or along the guidewire 112 so
that the balloon 104 is positioned at or near the treatment site
106.
[0082] The balloon 104 can include a balloon wall 130. The balloon
104 can expand from a collapsed configuration suitable for
advancing at least a portion of the catheter shaft 102 through a
patient's vasculature to an expanded configuration suitable for
anchoring the catheter 102 into position relative to the treatment
site 106.
[0083] The catheter shaft 110 of the catheter 102 can encircle one
or more optical fibers 122 (only one optical fiber 122 is
illustrated in FIG. 1 for clarity) in optical communication with
the energy source 124. The optical fiber 122 can be at least
partially disposed along and/or within the catheter shaft 110 and
at least partially within the balloon 104. In some embodiments, the
catheter shaft 110 can encircle multiple optical fibers 122 such as
a second optical fiber, a third optical fiber, etc.
[0084] The optical fiber 122 can vary depending on the design
requirements of the catheter system 100, and/or the energy source
124. It is understood that the optical fiber 122 can include
additional systems, subsystems, components, and elements than those
specifically shown and/or described herein. Additionally, or
alternatively, the optical fiber 122 can omit one or more of the
systems, subsystems, and elements that are specifically shown
and/or described herein.
[0085] The optical fiber 122 has a fiber proximal end 122P that is
positioned at or adjacent to the energy source 124, and a fiber
distal end 122D that can be positioned within the inflatable
balloon 104. The optical fiber 122 extends between the laser 124
and the balloon 104. The optical fiber 122 is in optical
communication with the energy source 124. It is appreciated that
the optical fiber 122 can be substituted with any suitable light
carrier (the optical fiber 122 is a light carrier) configured to
carry one or more sub-millisecond energy pulses and/or any suitable
energy source.
[0086] The controller 123 can control the energy source 124 so that
the energy source 124 can generate one or more energy pulses as
provided in greater detail herein. The controller 123 may also
perform any other relevant functions to control the operation of
the catheter 102.
[0087] The energy source 124 of the catheter system 100 can be
configured to provide one or more sub-millisecond energy pulses
that are sent to and received by the optical fiber 122. The optical
fiber 122 acts as a conduit for light energy that is generated by
the energy pulse(s). In certain embodiments, the energy source 124
(also sometimes referred to herein as a "laser") can include a
laser. In some such embodiments, the laser 124 can include one or
more seed sources 126 and one or more amplifiers 128. Each
amplifier 128 can be in optical communication with at least one of
the seed sources 126. The seed source(s) 126 can each emit a
relatively low-power seed pulse that is received and amplified by
the amplifier 128. The amplifier 128 can increase the power of the
seed pulse to generate the energy pulse. In one embodiment, the
laser 124 can include one seed source 126 and one amplifier
128.
[0088] Alternatively, the laser 124 can include a plurality of seed
sources 126 and one amplifier 128. Still alternatively, the laser
124 can include a plurality of seed sources 126 and a plurality of
amplifiers 128. It is appreciated that the laser 124 can be
substituted with any suitable energy source (the laser 124 is an
energy source) configured to provide one or more sub-millisecond
energy pulses that are sent to and received by the optical fiber
122.
[0089] The light energy that is generated by the energy pulse(s) is
delivered by the optical fiber 122 to a location within the balloon
104. The light energy induces plasma formation in the form of a
plasma pulse 134 that occurs in the balloon fluid 132 within the
balloon 104. The plasma pulse 134 causes rapid bubble formation and
imparts pressure waves upon the treatment site 106. Exemplary
plasma pulses 134 are shown in FIG. 1. The balloon fluid 132 can be
a liquid or a gas. As provided in greater detail herein, the
plasma-induced bubbles 134 are intentionally formed at some
distance away from the optical fiber 122 so that the likelihood of
damage to the optical fiber is decreased.
[0090] In various embodiments, the sub-millisecond pulses of light
can be delivered to near the treatment site 106 at a frequency of
from at least approximately 1 hertz (Hz) up to approximately 5000
Hz. In some embodiments, the sub-millisecond pulses of light can be
delivered to near the treatment site 106 at a frequency from at
least 30 Hz to 1000 Hz. In other embodiments, the sub-millisecond
pulses of light can be delivered to near the treatment site 106 at
a frequency from at least 10 Hz to 100 Hz. In yet other
embodiments, the sub-millisecond pulses of light can be delivered
to near the treatment site 106 at a frequency from at least 1 Hz to
30 Hz.
[0091] It is appreciated that the catheter system 100 herein can
include any number of optical fibers 122 in optical communication
with the laser 124 at the proximal portion 114 and with the balloon
fluid 132 within the balloon 104 at the distal portion 116. For
example, in some embodiments, the catheter system 100 herein can
include 1-30 optical fibers 122. In some embodiments, the catheter
system 100 herein can include greater than 30 optical fibers.
[0092] The manifold 136 can be positioned at or near the shaft
proximal end 114. The manifold 136 can include one or more proximal
end openings that can receive the one or more optical fibers, such
as optical fiber 122, the guidewire 112, and/or an inflation
conduit 140. The catheter system 100 can also include the fluid
pump 138 that is configured to inflate the balloon 104 with the
balloon fluid 132 and/or deflate the balloon 104 as needed.
[0093] The multiplexer (not shown) communicates with a single
energy source into one or more of the optical channels in a tightly
controlled manner. This approach can allow a single energy source
to be channeled sequentially through a plurality of channels with a
variable number.
[0094] As with all embodiments illustrated and described herein,
various structures may be omitted from the figures for clarity and
ease of understanding. Further, the figures may include certain
structures that can be omitted without deviating from the intent
and scope of the invention.
[0095] FIG. 2 is a schematic cross-sectional view of one embodiment
of the optical fiber 222, a coupling optics 242, and an energy
source (in the embodiment shown in FIG. 2, the energy source is a
laser 224) for use within the catheter system 100. The laser 224
can generate an energy pulse that is directed towards the coupling
optics 246. The laser 224 can be a pulsed IR laser or any suitable
laser. In various embodiments, the catheter system 100 can include
one or more emitter(s) 260 distributed along an active length(s) of
the calcified vascular lesion(s) located at the treatment site
106.
[0096] The energy source described herein can be any suitable
energy source for use within the catheter system 100. In some
embodiments, the optical fiber 222 can be substituted with any
suitable light carrier configured to receive an energy pulse. The
optical fiber 222 can receive the energy pulse and can direct the
energy pulse toward the emitter 260.
[0097] The coupling optics 242 couple and redirect the energy pulse
toward the optical fiber 222. The coupling optics 242 can vary
depending on the design requirements of the catheter system 100,
the optical fiber 222, and/or the laser 224. It is understood that
the coupling optics 242 can include additional systems, subsystems,
components, and elements than those specifically shown and/or
described herein. Additionally, or alternatively, the coupling
optics 242 can omit one or more of the systems, subsystems, and
elements that are specifically shown and/or described herein. The
coupling optics 242 can include a reflector 244 and a lens 246. The
reflector 244 can reflect the energy pulse towards the lens 246.
The lens 246 can focus the energy pulse so that the optical fiber
222 is capable of receiving the energy pulse of proper diameter
and/or size.
[0098] In the embodiment illustrated in FIG. 2, the optical fiber
222 can include a ferrule 248, a first fiber member 250, a tapered
portion 252 having a tapered portion length 254, a fused region
256, a second fiber member 258, and an emitter 260.
[0099] The ferrule 248 can organize and align the light carrier
(e.g., the optical fiber 222) to the coupling optics 242 in the
multiplexer (not shown). The ferrule 248 can vary depending on the
design requirements of the catheter system 100, the optical fiber
222, and/or the laser 224. It is understood that the ferrule 248
can include additional systems, subsystems, components, and
elements than those specifically shown and/or described herein.
Additionally, or alternatively, the ferrule 248 can omit one or
more of the systems, subsystems, and elements that are specifically
shown and/or described herein.
[0100] The ferrule 248 can be a rigid member configured to confine
and support the optical fiber. The ferrule 248 can also serve as a
connector and/or a mechanical splice in the catheter system 199.
The ferrule 248 can substantially surround any portion of the
optical fiber 222.
[0101] In certain embodiments, the system and method described
herein can include a segmented light carrier (e.g., the optical
fiber 222) that is larger at its fiber proximal end and reduces to
a smaller diameter towards the fiber distal end. Alternatively, the
light carrier can be larger at the fiber distal end and reduce to a
smaller diameter at the fiber proximal end.
[0102] The distal section (e.g., the second fiber member 258) can
consist of a single light carrier or a plurality of light carriers
leading to the emitter(s) 260. The proximal section (e.g., the
first fiber member 250) can also consist of a single light carrier
or a plurality of light carriers leading to the coupling optics
242. The tapered light carrier can improve pressure wave generation
and the catheter system 100 performance.
[0103] The first fiber member 250 can be configured to be fixed to
the ferrule 248. The first fiber member 250 can be a segment of the
optical fiber 222 that is proximal to the laser 224 and the
coupling optics 242. The first fiber member 250 can vary depending
on the design requirements of the catheter system 100, the optical
fiber 222, and/or the laser 224. It is understood that the first
fiber member 250 can include additional systems, subsystems,
components, and elements than those specifically shown and/or
described herein. Additionally, or alternatively, the first fiber
member 250 can omit one or more of the systems, subsystems, and
elements that are specifically shown and/or described herein.
[0104] In certain embodiments, the first fiber member 250 can
include the first tapered portion 252. In other embodiments, the
first fiber member 250 can be separately attached or coupled to the
tapered portion 252. The first fiber member 250 can be tapered
and/or otherwise varied to have a modified shape. The first fiber
member 250 can be a separate fiber or fiber member that is attached
to the tapered portion 252 and/or the second fiber member 258.
[0105] The tapered portion 252 can allow for the optical fiber 222
to have a reduced diameter at the distal portion of the optical
fiber 222 (e.g., the second fiber member 258). The tapered portion
252 can vary depending on the design requirements of the catheter
system 100, the optical fiber 222, and/or the laser 224. The shape,
taper, and/or dimensions of the tapered portion 252 can also vary.
The tapered portion 252 can have a tapered portion length 254. The
tapered portion length 254 can have varying lengths depending on
the design requirements of the catheter system 100 and/or the
optical fiber.
[0106] The location of the tapered portion 252 on the optical fiber
222 can vary. In some embodiments, the tapered portion 252 is
located in close proximity to the coupling optics 242. In other
embodiments, the tapered portion 252 is located closer to the
balloon 104. It is appreciated that the tapered portion 252 can be
located at any location along the optical fiber 222. In some
embodiments, the optical fiber 222 can include a plurality tapered
portions 252, located along varying locations of the optical fiber
222. It is appreciated that the optical fiber 222 can include any
number of tapered portions 252 to meet the design requirements of
the catheter system 100 and/or optical fiber 222.
[0107] The fused region 256 can be formed by fusing the first fiber
member 250 with the second fiber member 258. The fused region 256
can join fibers and/or fiber members of different diameters
together. In some embodiments, the fused region 256 can be fused
around a split and/or spliced portion (shown in FIGS. 3AA and 3BB)
of the optical fiber 222, so that the two severed portions of the
optical fiber 222 can be joined.
[0108] The fused region 256 can vary depending on the design
requirements of the catheter system 100, the optical fiber 222,
and/or the laser 224. The shape and/or dimensions of fused region
256 can also vary. The location of the fused region 256 on the
optical fiber 222 can vary. In some embodiments, the fused region
256 is located in close proximity to the coupling optics 242. In
other embodiments, the fused region 256 is located closer to the
balloon 104. It is appreciated that the fused region 256 can be
located in any location along the optical fiber 222.
[0109] The second fiber member 258 can be substantially similar to
the first fiber member 250. However, in certain embodiments, the
second fiber member 258 can have a smaller diameter than the first
fiber member 250. The second fiber member 258 can be a segment of
the optical fiber 222 that is distal to the laser 224 and the
coupling optics 242. The second fiber member 258 can be in optical
communication with the emitter 260.
[0110] The second fiber member 258 can vary depending on the design
requirements of the catheter system 100, the optical fiber 222, the
first fiber member 250, the tapered portion 252, and/or the emitter
260. It is understood that the second fiber member 258 can include
additional systems, subsystems, components, and elements than those
specifically shown and/or described herein. Additionally, or
alternatively, the second fiber member 258 can omit one or more of
the systems, subsystems, and elements that are specifically shown
and/or described herein.
[0111] While the first fiber member 250 and second fiber member 258
are described herein, it is appreciated that the optical fiber 222
can include any number of fiber members. In some embodiments, the
optical fiber 222 includes up to fifty fiber members. In other
embodiments, the first fiber member 250 having a first tapered
portion (not shown) can be fused to a second fiber member 258
having a second tapered portion (not shown) that can be fused to
the third fiber member (not shown. The optical fiber 222 can
include any number of fiber members that can each have any number
of tapered portions and can each include any number of fused
sections and/or other attachment points as known in the art.
[0112] The emitter 260 can be driven by the energy source. The
emitter 260 can be a plasma generator. The optical fiber 222 can
include one or more emitters 260. The emitter 260 can be located at
any position along the portion of the optical fiber 222 located
inside the balloon 104. The emitter 260 can produce one or more
plasma pulses 134.
[0113] The emitter 260 can vary depending on the design
requirements of the catheter system 100, the optical fiber 222,
and/or the laser 224. It is understood that the emitter 260 can
include additional systems, subsystems, components, and elements
than those specifically shown and/or described herein.
Additionally, or alternatively, the emitter 260 can omit one or
more of the systems, subsystems, and elements that are specifically
shown and/or described herein.
[0114] One method for tapering the light carrier (e.g., tapering
the optical fiber 222) includes tapering the larger proximal
section down by heating, drawing, and then cleaving it at the
smaller end. The light carrier assembly can be formed by fusing the
smaller diameter end to a smaller diameter carrier for the distal
section. The light carrier can be fused using a fused joint.
[0115] Another embodiment of the tapering method can include
heating and drawing the proximal section continuously to make a
longer light carrier with a smaller diameter for the distal
section. The tapering method can include creating a short, tapered
portion 252 and fusing the large end and small end to matching
diameter light carriers. This embodiment can require two fused
joints.
[0116] In certain embodiments, the light carrier (e.g., the optical
fiber 222) leading to the laser-driven pressure wave generating
device (e.g., the emitter 260) can include three sub-sections. The
proximal section can use a light carrier with a larger core
diameter than the distal section. The proximal section of the light
carrier begins at diameter D.sub.p and can be tapered or joined to
a tapered section that reduces the diameter to match the distal
section with diameter D.sub.d. The light energy can be coupled into
the end face of the proximal section.
[0117] The large diameter of the proximal face can reduce the
precision required in forming the coupled light energy beam and
aligning the coupling optics 242 to the light guide (e.g., the
optical fiber 222). This design can reduce the multiplexer accuracy
requirements and the optomechanical tolerances for connectorizing
the light carrier. The tapered portion 252 can preserve the energy
pulse and transmits the energy pulse to the smaller diameter
carrier with minimal losses.
[0118] In certain embodiments, etendue is conserved in the light
guide. Etendue conservation mandates that the product of numerical
aperture (NA) and diameter remain constant. As a result, the NA of
the distal section of the taper must increase so that
NA.sub.d=(D.sub.p/D.sub.d) NA.sub.p. For example, an optical fiber
222 with an intrinsic NA=0.22 that is tapered from 200 microns to
100 microns increases the NA to NA=0.44. If the smaller diameter
end of the taper were fused to a light guide with similar NA=0.22,
the mismatch would cause significant coupling losses into the
cladding of the smaller fiber.
[0119] In various embodiments, the optical fiber 222 can be tapered
from 220 microns to 100 microns. The optical fiber 222 described
herein can be tapered from an initial diameter of 100 .mu.m, 110
.mu.m, 120 .mu.m, 130 .mu.m, 140 .mu.m, 150 .mu.m, 160 .mu.m, 170
.mu.m, 180 .mu.m, 190 .mu.m, 200 .mu.m, 220 .mu.m, 240 .mu.m, 260
.mu.m, 280 .mu.m, 300 .mu.m, 320 .mu.m, 340 .mu.m, 360 .mu.m, 380
.mu.m, 400 .mu.m, 420 .mu.m, 440 .mu.m, 460 .mu.m, 480 .mu.m, 500
.mu.m, 520 .mu.m, 540 .mu.m, 560 .mu.m, 580 .mu.m, 600 .mu.m, 620
.mu.m, 740 .mu.m, 760 .mu.m, 780 .mu.m, 800 .mu.m, 850 .mu.m, 900
.mu.m, 1mm or greater than 1mm to a final diameter of less than 1
.mu.m, 1 .mu.m, 5 .mu.m, 10 .mu.m, 20 .mu.m, 30 .mu.m, 40 .mu.m, 50
.mu.m, 60 .mu.m, 70 .mu.m, 80 .mu.m, 90 .mu.m, 100 .mu.m, 110
.mu.m, 120 .mu.m, 130 .mu.m, 140 .mu.m, 150 .mu.m, 160 .mu.m, 170
.mu.m, 180 .mu.m, 190 .mu.m, 200 .mu.m, 220 .mu.m, 240 .mu.m, 260
.mu.m, 280 .mu.m, 300 .mu.m, 320 .mu.m, 340 .mu.m, 360 .mu.m, 380
.mu.m, 400 .mu.m, 420 .mu.m, 440 .mu.m, 460 .mu.m, 480 .mu.m, 500
.mu.m, 520 .mu.m, 540 .mu.m, 560 .mu.m, 580 .mu.m, 600 .mu.m, 620
.mu.m, 740 .mu.m, 760 .mu.m, 780 .mu.m, 800 .mu.m, 850 .mu.m, 900
.mu.m. It is appreciated that the optical fibers and/or light
carriers illustrated and/or described herein can be tapered to have
final diameters and initial diameters that can fall within a range,
wherein any of the foregoing numbers can serve as the lower or
upper bound of the range, provided that the lower bound of the
range is a value less than the upper bound of the range. The
optical fibers and/or light carriers described herein can have
final diameters and initial diameters that fall outside of the
range described herein.
[0120] One method to avoid the coupling losses is to use a light
carrier with lower NA on the fiber proximal end having the larger
diameter and a light carrier with NA greater by the ratio of
diameters for the smaller distal section. The tapering process from
D.sub.p down to D.sub.d matches the numerical apertures of the two
sections. In some embodiments, the tapered portion 252 can be
formed to produce an adiabatic change in light bending and
resulting NA to minimize losses through the transition.
[0121] Stimulated Brillouin Scattering (SBS) is a non-linear
process in the light carrier that can limit total energy
transmission. In SBS, an intense beam of light energy can interact
with an acoustic wave in the medium, leading to a weak reflected
beam. The reflected beam is generally referred to as a Stokes wave,
and the original beam can then interfere to amplify the acoustic
wave through electrostriction. The power in the reflected beam can
increase nonlinearly with input beam power. As a result, energy
throughput can be continually reduced with input power, effectively
clamping the peak transmitted power which significantly limits the
conversion efficiency and yield of the emitter.
[0122] SBS depends on many variables including the wavelength and
bandwidth of the input light energy, physical properties of the
light carrier medium, and its mechanical dimensions. In general,
increasing the diameter of a light guide by a factor of two
increases the power threshold for the onset of SBS by a factor of
four. SBS originates in a region of the light guide closer to the
launch end. If this can be avoided in the larger carrier then the
full power launched into it can be coupled into the smaller light
carrier further down. The larger diameter of the proximal section
allows significantly more power to be coupled to the light guide
assembly and transmit to the fiber distal end.
[0123] In some embodiments, the proximal light carrier can be a
doped optical fiber that improves transmission characteristics and
further suppresses the onset of SBS. Some examples of suitable
dopants are GeO.sub.2, P.sub.2O.sub.3, TiO.sub.2, B.sub.2O.sub.3,
F.sub.2, Al.sub.2O.sub.3. Doped fibers can be much more expensive
per unit length than conventional, pure silica fibers.
[0124] This approach can allow a short length of an expensive fiber
to be used to suppress SBS with a much longer assembly made of
lower-cost fiber. Other approaches could implement a short length
of photonic crystal fiber, hollow-core fiber, chiral fibers, or
similar structured optical fiber in the proximal section and
conventional pure fused silica fiber through the longer length of
the catheter system 100. This configuration can allow a short
length of more expensive fiber to be used in the proximal section
with lower costs for the distal section, achieving similar
results.
[0125] FIG. 3A is a schematic cross-sectional view of one
embodiment of an optical fiber 322 for use within the catheter
system 100. As shown in FIG. 3A the optical fiber 322 can include a
first fiber member 350, a fused region 356, a second fiber member
358 including second fiber legs 362A-C. The optical fiber 322 can
include any number of second fiber legs 362.
[0126] The optical fiber 322 can include a single proximal section
joined to a plurality of distal sections. In this embodiment, three
distal carriers (e.g., second fiber legs 362A-C) can be fused to a
single proximal carrier. The distal carriers can have the same
diameter as that used in the proximal section or they can have
smaller diameters. In other embodiments, the distal section
comprises N light carriers with smaller diameters than the proximal
section.
[0127] The transmission coupling efficiency can be maximized when
the combined end face area of the distal section equals that of the
proximal section, D.sub.d=D.sub.p/ {square root over (N)}. As a
result, a 200/220 .mu.m core/cladding light carrier matches well
with three 105/125 .mu.m carriers as illustrated in FIG. 3A. The
transmission coupling efficiency can be further optimized by
thinning the cladding (not shown) on the distal carriers near the
fused region 356 to bring the cores closer together and better
match with the core of the proximal section. Compressing the region
where the cores are joined during fusing can improve overlap.
[0128] One advantage of the embodiment illustrated in FIG. 3A is
that it eliminates the need to split the energy source into two
separate beams and couple each of the beams into separate light
carriers when powering two emitters 260 simultaneously. This
embodiment can have another advantage of simplifying multiplexer
architecture and optics. The embodiment shown in FIG. 3A can also
reduce the losses from having two separate beam paths and separate
Fresnel losses occurring at the end face of two light carriers.
[0129] While there may be sizeable losses in a fused splitter
(e.g., the fused region 356), these losses can be comparable to
losses in a two-leg multiplexer architecture with complex coupling
optics. The fused splitter can simplify multiplexer architecture,
can reduce the alignment tolerances allowing simpler optics with
improved transmission, and can eliminate losses due to splitting
optics and the launch interface.
[0130] FIG. 3B is a schematic cross-sectional view of another
embodiment of another optical fiber 322 for use within the catheter
system 100. The embodiment shown in FIG. 3B illustrates a highly
optimized 1.times.2 splitter that transitions from a 200 .mu.m core
proximal section to two 105 .mu.m core distal sections. The
transition between sections can be optimized by tapering the
proximal light carrier to have an area equal to two times that of a
105 .mu.m carrier. The two distal carriers can be formed to better
match up with the fiber proximal end.
[0131] A separate capillary 364 can be placed around the fused
assemblage (e.g., the fused region 356) and fused to optimize the
cross-section and the area matching. This approach can be used to
improve coupling efficiency for any number of carriers in the
splitter. The capillary 364 can be drawn to tight tolerances and
can be suitable for use in the catheter system 100. The capillary
364 can vary depending on the design requirements of the catheter
system 100 and/or the optical fiber 322. It is understood that the
capillary 364 can include additional systems, subsystems,
components, and elements than those specifically shown and/or
described herein. Additionally, or alternatively, the capillary 364
can omit one or more of the systems, subsystems, and elements that
are specifically shown and/or described herein.
[0132] FIG. 3AA is a cross-sectional view of the optical fiber
taken on line 3AA-3AA in FIG. 3A. As illustrated in FIG. 3AA, the
cross-sectional view demonstrates that the fused region 356 can
include the first fiber member 350 and the second fiber member legs
362A-C. The first fiber member 350 can be fused to the second fiber
member legs 362A-C at different locations so that portions of the
outer perimeter of the first fiber member 350 is fused to portions
the outer perimeter of the second fiber leg 362A, the second fiber
leg 362B, and the second fiber leg 362C.
[0133] FIG. 3BB is a cross-sectional view of the optical fiber
taken on line 3BB-3BB in FIG. 3B. As illustrated in FIG. 3BB, the
cross-sectional view demonstrates that the fused region 356 can
include the first fiber member 350 and the second fiber member legs
362A-B. The fused region 356 can be substantially surrounded by the
capillary 364.
[0134] FIG. 4A is a schematic cross-sectional view of another
embodiment of the optical fiber 422A, the coupling optics 442A
(e.g., a reflector 444A and a lens 446A), and the energy source
(e.g., a laser 424A) for use within the catheter system 100
(illustrated in FIG. 1). In some embodiments, the optical fiber
422A can include a ferrule 448A, a first fiber member 450A, a fused
region 456A, an emitter 460A, and an endcap 466A.
[0135] The endcap 466A can provide a larger surface area to spread
the converging incident beam over before it focuses down the energy
source to couple into the light carrier. The shape, configuration
and size of the endcap 466A can vary depending on the design
requirements of the catheter system 100 and/or the optical fiber
422A. In one embodiment, the endcap 466A can have a substantially
cylindrical configuration. Alternatively, the endcap 466A can have
another suitable configuration.
[0136] The embodiment shown in FIG. 4A illustrates a direct
approach to improving coupling to the smaller light carriers using
the endcap 466A fused to the proximal end. In general, the damage
threshold for optical material is much lower at an air interface
than within the bulk material, sometimes by an order of
magnitude.
[0137] This approach can reduce peak irradiance at the surface,
thereby increasing the damage threshold for the light carrier
assembly. The damage threshold near the end face of the light
carrier is close to the bulk threshold for the formation materials.
This embodiment allows a significantly greater amount of energy to
be coupled into a small diameter light carrier. The converging
incident beam can be tightly centered on the endcap 466A and can be
tightly aligned within the ferrule 448A to achieve alignment for
optimal coupling. In certain embodiments, the tight alignment is
necessary to center the converging incident beam on the endcap
466A.
[0138] FIG. 4B is a schematic cross-sectional view of another
embodiment of the optical fiber 422B, the coupling optics 442B, and
the energy source (e.g., the laser 424B) for use within the
catheter system 100 (illustrated in FIG. 1). The embodiment
illustrated in FIG. 4B features a tapered assembly. The tapered
light carrier can be a short section (e.g., the tapered portion
452B) confined within the ferrule 456B. This approach can provide a
large end face for defocusing the incident beam and coupling high
energies thereby increasing the assembly damage threshold.
Simultaneously, the embodiment of FIG. 4B can reduce the demands of
aligning with the smaller light carrier through the optical guiding
of energy through the tapered portion 452B.
[0139] The present invention is also directed toward methods for
treating a treatment site 106 (illustrated in FIG. 1) within or
adjacent to a vessel wall or heart valve, with such methods
utilizing the devices disclosed herein.
Fibers
[0140] The optical fibers suitable for use herein can include
various types of fibers suitable for optical communication with an
energy source, such as lasers and lamps. In some embodiments,
optical fibers can include fiber connectors and fiber tapers. Fiber
tapers can be packaged with a solid metal tube in tens of
millimeter length. To convert light from a large core fiber into a
small core fiber, fiber tapers that taper a larger core fiber into
a smaller core for splicing can be an effective method to minimize
the insertion loss. In certain embodiments, fiber tapers can be
integrated into fiber connectors and can form a new type of fiber
device called a tapered fiber connector.
[0141] The fiber connectors can be configured to couple lights from
one fiber to another fiber. The fiber connectors can include
polished ferrules. The fibers can be encircled into the fiber
connectors with epoxy. There are tens of different styles of fiber
connectors, including ferrules with an outer diameter of 1.25 mm LC
and ones with 2.5 mm SC. The inner diameter of a ferrule depends on
the fiber sizes, sometimes between 126.about.127 .mu.m diameter for
single-mode fibers.
[0142] In some embodiments, the ferrules described herein can have
diameters (both inner diameters and outer diameters) of greater
than or equal to 1 .mu.m, 5 .mu.m, 10 .mu.m, 20 .mu.m, 30 .mu.m, 40
.mu.m, 50 .mu.m, 60 .mu.m, 70 .mu.m, 80 .mu.m, 90 .mu.m, 100 .mu.m,
110 .mu.m, 120 .mu.m, 130 .mu.m, 140 .mu.m, 150 .mu.m, 160 .mu.m,
170 .mu.m, 180 .mu.m, 190 .mu.m, 200 .mu.m, 220 .mu.m, 240 .mu.m,
260 .mu.m, 280 .mu.m, 300 .mu.m, 320 .mu.m, 340 .mu.m, 360 .mu.m,
380 .mu.m, 400 .mu.m, 420 .mu.m, 440 .mu.m, 460 .mu.m, 480 .mu.m,
500 .mu.m, 520 .mu.m, 540 .mu.m, 560 .mu.m, 580 .mu.m, 600 .mu.m,
620 .mu.m, 740 .mu.m, 760 .mu.m, 780 .mu.m, 800 .mu.m, 850 .mu.m,
900 .mu.m, 1 mm, 1.5 mm, 2.0 mm, 2.5 mm, 3.0 mm, 3.5 mm, 4.0 mm or
greater than 4.0 mm. It is appreciated that the ferrules
illustrated and/or described herein can have diameters (both inner
diameters and outer diameters) that can fall within a range,
wherein any of the foregoing numbers can serve as the lower or
upper bound of the range, provided that the lower bound of the
range is a value less than the upper bound of the range. The
ferrules described herein can have diameters (both inner diameters
and outer diameters) that fall outside of the range described
herein.
[0143] For high power laser fiber coupling, a large core diameter
fiber can be used to reduce the power density at the fiber coupling
surface to enhance the damage threshold. However, a large diameter
fiber is not flexible for many applications, such as catheters for
medical treatments. In these applications, converting light power
from a large diameter fiber into a small diameter fiber is
important. Connecting or splicing a large core fiber with a small
core fiber can directly result in unacceptable insertion loss.
[0144] One embodiment of a method for converting light power
includes tapering the larger core diameter fibers to match the
smaller core diameter fiber and then splicing the fiber tapers to
the small core fibers. However, fiber tapers and splice joints need
to be well packaged, usually 3 mm diameter and 50 mm long metal
tubing, which is extremely inconvenient in many applications.
[0145] By integrating fiber connectors with fiber tapers a new type
of fiber connector is created, a tapered fiber connector. This type
of fiber connector is regular in size, but a fiber taper is
encircled with epoxy. Any suitable type of fiber connectors
including all single-mode fiber connectors can be improved into
tapered fiber connectors for receiving lights as the transverse
offset will not introduce any significant loss.
[0146] In various embodiments, fusion splicers can taper fibers and
splice the fiber tapers onto small core fibers. In other
embodiments, other devices and methods can be used to taper fibers
and splice the fiber tapers onto small core fibers. Fibers can be
tapered using a hydrogen flame to heat a mid-section of fiber that
is held under tension. Fibers can be tapered using known devices
and methods within the art.
[0147] The fiber tapers and splice joints can be encircled in fiber
ferrules with epoxy for polishing. Epoxies that can be used herein
include thermal epoxies, room temperature cure epoxies (such as
ND353), UV curing epoxies (such as the LOCTITE.RTM. 4310 UV
adhesive), and other suitable epoxies known within the art. The
processing can be simple and low cost and the fiber connectors that
are integrated with fiber tapers can be configured for high power
laser coupling. One type of fiber connector that can be used is a
fiber end-cap for high power laser input and output with reduced
power density on fiber surfaces. Fiber end-caps can require
accurate alignment as end-cap glass is equivalent to a free space
rather than a waveguide. However, fiber tapers can still function
as waveguides and thus alignment is not necessary.
[0148] In some embodiments, when core/cladding diameters of 200/220
.mu.m fibers are selected to couple high power laser and
core/cladding diameters of 105/125 .mu.m fibers are used to build
catheters for medical treatments, the process of converting laser
power from the large core diameter fibers to the small core fibers
is important.
[0149] For example, when directly splicing core/cladding diameters
of 200/220 .mu.m larger fibers onto core/cladding 105/125 .mu.m
smaller fibers together, a large portion of the light will not
couple from the large fiber into the small fiber, which results in
a high insertion loss. As an estimation, the ratio of two core
overlapping is:
( 105 200 ) 3 = 0.275 [ Equation .times. 1 ] ##EQU00001##
[0150] which is about a 6 dB loss. This insertion loss is even
higher for higher-order modes as the higher-order modes are likely
distributed far from the core central area. The configuration of
step-index fibers is shown below, the refractive index of the fiber
core n.sub.1 is slightly larger than the cladding n.sub.2. To form
a total internal reflection for a light's propagation along the
fiber, the maximum incident angle a must meet the following
conditions:
{ sin .function. ( .alpha. ) = n .times. 1 sin .function. ( .beta.
) n .times. 1 cos .times. ( .beta. ) = n .times. 2 [ Equation
.times. 2 ] ##EQU00002##
[0151] Simplifying Equations 1 and 2:
sin(.alpha.)= {square root over (n.sub.1.sup.2-n.sub.2.sup.2)}=NA
(3)
[0152] NA is the numerical aperture of the fibers, for 0.22
numerical aperture, the maximum incident angle a is 12.7 degrees.
For a non-tapered fiber, the angles of light remain unchanged along
the fiber and emit at the same angles .alpha.. However, for a
tapered fiber, the emitting angle will be larger than the incident
angle .alpha., depending on the tapering angle and length.
[0153] When the incident angle of light is small enough, or the
light beam effective NA is significantly smaller than the small
fiber NA.sub.2, with a certain tapering angle and tapering length,
it is possible that the effective NA of the emitting lights from
the fiber taper is still within the smaller fiber acceptable angle
range of arcsin(NA.sub.2), 12.7 degrees for 0.22 numerical
aperture. The tapering angle .delta. is expressed as:
.delta. = arctan .function. ( D 1 - D 2 2 .times. L ) .apprxeq. D 1
- D 2 2 .times. L [ Equation .times. 4 ] ##EQU00003##
the lights get 2.delta. angle to increase at every reflection due
to the tapered surface. For tapering core diameter of 200 .mu.m
large fiber going into a 105 .mu.m small core with a 4 mm taper
length makes the tapering angle .delta.=0.68 degree. For tapering
single-mode fibers, in order to keep the fundamental mode in the
fiber virtually unchanged, the adiabatic tapers require the
tapering angle to be small enough 0.35 degrees for SMF28. For
multimode power coupling, the tapering angle could be larger, but
it can keep lights from leaking into the cladding.
[0154] In certain embodiments, when a 3 mm diameter parallel
free-space laser beam is focused by a 50 mm focal lens and coupled
to a fiber taper, the NA of the incident beam is:
N .times. A = arctan .function. ( 3 2 .times. 50 ) = 0 . 0 .times.
3 .about. 1 . 7 .times. 2 .degree. [ Equation .times. 5 ]
##EQU00004##
[0155] The light angles increase by 2.delta. for every reflection
at the surface of fiber tapers, thus the pitches between two
reflections along the fiber become shorter and shorter while the
angles become larger and larger. In order to prevent light leaking
from the fiber core to the cladding, the largest angle of lights
must be not more than arcsin(NA.sub.2).
[0156] When a 3 mm diameter free space laser beam is focused by a
lens with 50 mm focal length, tapering a 200 .mu.m large diameter
fiber into a small core 105 .mu.m (fiber taper 200/105 .mu.m), the
fiber taper can convert all lights from the large core fiber into
105 .mu.m small core fiber with no light leakage to the fiber
cladding at the tapering area and the splice joint.
[0157] For tapering large diameters of 200 .mu.m, 300 .mu.m, and
400 .mu.m into a 105 .mu.m small core with a 5 mm taper length,
simulations show all light from larger core diameter fibers can be
fully coupled to the small core fibers like an optical funnel. For
fiber tapers of 1000/105 .mu.m and a 5 mm taper length, simulations
show light leakage from the fiber core to the cladding, which
results in a significant insertion loss as shown below. For fiber
tapers of 200/105 .mu.m, simulations also show that the
light-emitting angle with respect to the taper length is curved.
The smaller angles or beam sizes are usually desired and thus the
optimized taper length is at least 4.about.5 mm.
[0158] In some embodiments, 500 .mu.m core diameters can be tapered
into a 105 .mu.m small core for light conversion. However,
simulations show that the tapering length must be longer than 5 mm
to avoid lights leaking into the cladding. The taper length can be
15 mm long for achieving a smaller emitting angle.
[0159] A fiber fusion splicer FSM100P can taper fibers from up to
500 .mu.m large fibers into a small size. Comparing with a 105/125
.mu.m fiber for high power light coupling, large-diameter fibers
can significantly reduce the power density. For tapered connectors
with fiber tapers with diameters of 200 .mu.m, 300, 400 .mu.m, and
500 .mu.m, the power densities can be reduced by -4, 8, 15, and 22
times, respectively. Fusing fiber for tapering can expand the fiber
core slightly, fiber core diameters can be tapered to be slightly
smaller, e.g. taper 200 .mu.m core diameter to -95 .mu.m core for
matching 105/125 .mu.m fibers.
[0160] In some embodiments, the optical fibers and/or light
carriers described herein can have diameters of greater than or
equal to 1 .mu.m, 5 .mu.m, 10 .mu.m, 20 .mu.m, 30 .mu.m, 40 .mu.m,
50 .mu.m, 60 .mu.m, 70 .mu.m, 80 .mu.m, 90 .mu.m, 100 .mu.m, 110
.mu.m, 120 .mu.m, 130 .mu.m, 140 .mu.m, 150 .mu.m, 160 .mu.m, 170
.mu.m, 180 .mu.m, 190 .mu.m, 200 .mu.m, 220 .mu.m, 240 .mu.m, 260
.mu.m, 280 .mu.m, 300 .mu.m, 320 .mu.m, 340 .mu.m, 360 .mu.m, 380
.mu.m, 400 .mu.m, 420 .mu.m, 440 .mu.m, 460 .mu.m, 480 .mu.m, 500
.mu.m, 520 .mu.m, 540 .mu.m, 560 .mu.m, 580 .mu.m, 600 .mu.m, 620
.mu.m, 740 .mu.m, 760 .mu.m, 780 .mu.m, 800 .mu.m, 850 .mu.m, 900
.mu.m, 1mm, 1.5mm, 2.0 mm, 2.5 mm, 3.0 mm or greater than 3.0 mm.
It is appreciated that the optical fibers and/or light carriers
illustrated and/or described herein can have diameters that can
fall within a range, wherein any of the foregoing numbers can serve
as the lower or upper bound of the range, provided that the lower
bound of the range is a value less than the upper bound of the
range. The optical fibers and/or light carriers described herein
can have diameters that fall outside of the range described
herein.
[0161] In various embodiments, the optical fibers and/or light
carriers described herein can have taper lengths of greater than or
equal to 0.5 mm, 1.0 mm, 1.5 mm, 2.0 mm, 2.5 mm, 3.0 mm, 3.5 mm,
4.0 mm, 4.5 mm, 5.0 mm, 5.5 mm, 6.0 mm, 6.5 mm, 7.0 mm, 7.5 mm, 8.0
mm, 8.5 mm, 9.0 mm, 9.5 mm, 10.0 mm, 11.0 mm, 12.0 mm, 13.0 mm,
14.0 mm, 15.0 mm, 20 mm, 25 mm, 30 mm or greater than 30 mm. It is
appreciated that the optical fibers and/or light carriers
illustrated and/or described herein can have taper lengths that can
fall within a range, wherein any of the foregoing numbers can serve
as the lower or upper bound of the range, provided that the lower
bound of the range is a value less than the upper bound of the
range. The optical fibers and/or light carriers described herein
can have taper lengths that fall outside of the range described
herein.
Lasers
[0162] The lasers suitable for use herein can include various types
of lasers including lasers and lamps. Suitable lasers can include
short pulse lasers on the sub-millisecond timescale. In some
embodiments, the laser can include lasers on the nanosecond (ns)
timescale. The lasers can also include short pulse lasers on the
picosecond (ps), femtosecond (fs), and microsecond (us) timescales.
It is appreciated that there are many combinations of laser
wavelengths, pulse widths, and energy levels that can be employed
to achieve plasma in the balloon fluid of the catheters illustrated
and/or described herein. In various embodiments, the pulse widths
can include those falling within a range including from at least 10
ns to 200 ns. In some embodiments, the pulse widths can include
those falling within a range including from at least 20 ns to 100
ns. In other embodiments, the pulse widths can include those
falling within a range including from at least 1 ns to 5000 ns.
[0163] Exemplary nanosecond lasers can include those within the UV
to IR spectrum, spanning wavelengths of about 10 nanometers to 1
millimeter. In some embodiments, the lasers suitable for use in the
catheter systems herein can include those capable of producing
light at wavelengths of from at least 350 nm to 2000 nm. In some
embodiments, the lasers can include those capable of producing
light at wavelengths of from at least 700 nm to 3000 nm. In some
embodiments, the lasers can include those capable of producing
light at wavelengths of from at least 100 nm to 10 micrometers
(.mu.m). Nanosecond lasers can include those having repetition
rates of up to 200 kHz. In some embodiments, the laser can include
a Q-switched thulium:yttrium-aluminum-garnet (Tm:YAG) laser. In
some embodiments, the laser can include a
neodymium:yttrium-aluminum-garnet (Nd:YAG),
holmium:yttrium-aluminum-garnet (Ho:YAG),
erbium:yttrium-aluminum-garnet (Er:YAG), excimer laser, helium-neon
laser, carbon dioxide laser, as well as doped, pulsed, fiber
lasers.
Pressure Waves
[0164] The catheters illustrated and/or described herein can
generate pressure waves having maximum pressures in the range of at
least 1 megapascal (MPa) to 100 MPa. The maximum pressure generated
by a particular catheter will depend on the laser, the absorbing
material, the bubble expansion, the propagation medium, the balloon
material, and other factors. In some embodiments, the catheters
illustrated and/or described herein can generate pressure waves
having maximum pressures in the range of at least 2 MPa to 50 MPa.
In other embodiments, the catheters illustrated and/or described
herein can generate pressure waves having maximum pressures in the
range of at least 2 MPa to 30 MPa. In yet other embodiments, the
catheters illustrated and/or described herein can generate pressure
waves having maximum pressures in the range of at least 15 MPa to
25 MPa. In some embodiments, the catheters illustrated and/or
described herein can generate pressure waves having peak pressures
of greater than or equal to 1 MPa, 2 MPa, 3 MPa, 4 MPa, 5 MPa, 6
MPa, 7 MPa, 8 MPa, 9 MPa, 10 MPa, 11 MPa, 12 MPa, 13 MPa, 14 MPa,
15 MPa, 16 MPa, 17 MPa, 18 MPa, 19 MPa, 20 MPa, 21 MPa, 22 MPa, 23
MPa, 24 MPa, or 25 MPa, 26 MPa, 27 MPa, 28 MPa, 29 MPa, 30 MPa, 31
MPa, 32 MPa, 33 MPa, 34 MPa, 35 MPa, 36 MPa, 37 MPa, 38 MPa, 39
MPa, 40 MPa, 41 MPa, 42 MPa, 43 MPa, 44 MPa, 45 MPa, 46 MPa, 47
MPa, 48 MPa, 49 MPa, or 50 MPa. It is appreciated that the
catheters illustrated and/or described herein can generate pressure
waves having operating pressures or maximum pressures that can fall
within a range, wherein any of the foregoing numbers can serve as
the lower or upper bound of the range, provided that the lower
bound of the range is a value less than the upper bound of the
range.
[0165] Therapeutic treatment can act via a fatigue mechanism or a
brute force mechanism. For a fatigue mechanism, operating pressures
would be about at least 0.5 MPa to 2 MPa, or about 1 MPa. For a
brute force mechanism, operating pressures would be about at least
20 MPa to 30 MPa, or about 25 MPa. Pressures between the extreme
ends of these two ranges may act upon a treatment site using a
combination of a fatigue mechanism and a brute force mechanism.
[0166] The pressure waves described herein can be imparted upon the
treatment site from a distance within a range from at least 0.01
millimeters (mm) to 25 mm extending radially from a longitudinal
axis of a catheter placed at a treatment site. In some embodiments,
the pressure waves can be imparted upon the treatment site from a
distance within a range from at least 1 mm to 20 mm extending
radially from a longitudinal axis of a catheter placed at a
treatment site. In other embodiments, the pressure waves can be
imparted upon the treatment site from a distance within a range
from at least 0.1 mm to 10 mm extending radially from a
longitudinal axis of a catheter placed at a treatment site. In yet
other embodiments, the pressure waves can be imparted upon the
treatment site from a distance within a range from at least 1.5 mm
to 4 mm extending radially from a longitudinal axis of a catheter
placed at a treatment site. In some embodiments, the pressure waves
can be imparted upon the treatment site from a range of at least 2
MPa to 30 MPa at a distance from 0.1 mm to 10 mm. In some
embodiments, the pressure waves can be imparted upon the treatment
site from a range of at least 2 MPa to 25 MPa at a distance from
0.1 mm to 10 mm. In some embodiments, the pressure waves can be
imparted upon the treatment site from a distance that can be
greater than or equal to 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm,
0.6 mm, 0.7 mm, 0.8 mm, or 0.9 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6
mm, 7 mm, 8 mm, 9 mm, or 10 mm, or can be an amount falling within
a range between, or outside the range of any of the foregoing.
[0167] The systems and methods described herein provide improved
optical coupling to an individual light carrier that is organized
in a multi-channel array. The advantage of the improved optical
coupling is to increase the damage threshold and coupling
efficiency while reducing demand on mechanical tolerances.
[0168] The systems and methods provided herein improve an optical
damage threshold and energy throughput while maintaining a small
diameter section leading to the plasma generator. The advantage of
the improved optical damage threshold and energy throughput is to
minimize the mechanical cross-section and bending stiffness of the
light guide bundle and catheter.
[0169] The systems and methods provided herein allow the use of
larger light carriers in the proximal section of the single-use
device (sometimes referred to herein as a "SUD") that are easy to
align optics with to couple light into while allowing smaller
carriers to be used to in the distal section to optimize key
mechanical characteristics such as crossing the profile and bending
stiffness. Advantages of this approach are that it: 1) reduces
demand on the connector tolerances for alignment of the light
carrier to the coupling optics and mechanical tolerances of their
location in a multi-channel array, 2) reduces system performance
dependence on the accuracy of connecting and aligning the
multi-channel array to the multiplexer, 3) reduces dependence on
the accuracy of the positioning mechanism in the multiplexer and
associated quality and precision of its optical and mechanical
components, 4) makes it possible to use lower-cost, lower accuracy
ferrules on the SUD, reducing costs, 5) increases optical damage
threshold at the proximal end face of the light carrier allowing
increased energy to drive the emitters, and 6) reduces transmission
losses in the light carrier that are due to non-linear optical
processes that increase with the decrease in light carrier
diameter.
[0170] The systems and methods described herein reduce the optical
coupling dependence on the precision and mechanical tolerance
stack-ups of assemblies and true alignment for light carrier(s),
ferrule(s), connector(s), and receptacle(s), thereby making it
possible to use low-cost, low-precision components on the SUD and
improve the cost of goods sold.
[0171] The systems and methods described herein reduce the
multiplexer performance dependence on the accuracy of the
positioning mechanism and the associated quality and precision of
its optical and mechanical components, thereby improving the speed
and performance of the multiplexer and the multi-channel ferrule
system.
[0172] The systems and methods described herein increase the damage
threshold of the light carrier(s) and allow higher energies to be
coupled into the light carrier(s) and to the emitter(s) while
enabling the use of smaller carrier(s) through the critical
sections of the catheter.
[0173] It should also be noted that, as used in this specification
and the appended claims, the phrase "configured" describes a
system, apparatus, or other structure that is constructed or
configured to perform a particular task or adopt a particular
configuration. The phrase "configured" can be used interchangeably
with other similar phrases such as arranged and configured,
constructed and arranged, constructed, manufactured and arranged,
and the like.
[0174] As used herein, the recitation of numerical ranges by
endpoints shall include all numbers subsumed within that range,
inclusive (e.g., 2 to 8 includes 2, 2.1, 2.8, 5.3, 7, 8, etc.).
[0175] It is recognized that the figures shown and described are
not necessarily drawn to scale, and that they are provided for ease
of reference and understanding, and for relative positioning of the
structures.
[0176] The headings used herein are provided for consistency with
suggestions under 37 CFR 1.77 or otherwise to provide
organizational cues. These headings shall not be viewed to limit or
characterize the invention(s) set out in any claims that may issue
from this disclosure. As an example, a description of a technology
in the "Background" is not an admission that technology is prior
art to any invention(s) in this disclosure. Neither is the
"Summary" or "Abstract" to be considered as a characterization of
the invention(s) set forth in issued claims.
[0177] The embodiments described herein are not intended to be
exhaustive or to limit the invention to the precise forms disclosed
in the following detailed description. Rather, the embodiments are
chosen and described so that others skilled in the art can
appreciate and understand the principles and practices. As such,
aspects have been described with reference to various specific and
preferred embodiments and techniques. However, it should be
understood that many variations and modifications may be made while
remaining within the spirit and scope herein.
[0178] It is understood that although a number of different
embodiments of the catheter systems have been illustrated and
described herein, one or more features of any one embodiment can be
combined with one or more features of one or more of the other
embodiments, provided that such combination satisfies the intent of
the present invention.
[0179] While a number of exemplary aspects and embodiments of the
catheter systems have been discussed above, those of skill in the
art will recognize certain modifications, permutations, additions,
and sub-combinations thereof. It is therefore intended that the
following appended claims and claims hereafter introduced are
interpreted to include all such modifications, permutations,
additions, and sub-combinations as are within their true spirit and
scope, and no limitations are intended to the details of
construction or design herein shown.
* * * * *