U.S. patent application number 13/443138 was filed with the patent office on 2012-08-16 for in-vivo visualization system.
This patent application is currently assigned to Boston Scientific Scimed, Inc.. Invention is credited to Mark L. Adams, Oscar R. Carrillo, JR., Yem Chin, Michael S.H. Chu, Jesse Leonard Farris, III, David I. Freed, John B. Golden, Todd A. Hall, John O. McWeeney, Benjamin E. Morris, David W. Robertson, James F. Schuerman, Jozef Slanda, Brian Keith Wells.
Application Number | 20120209073 13/443138 |
Document ID | / |
Family ID | 34966138 |
Filed Date | 2012-08-16 |
United States Patent
Application |
20120209073 |
Kind Code |
A1 |
McWeeney; John O. ; et
al. |
August 16, 2012 |
IN-VIVO VISUALIZATION SYSTEM
Abstract
Several embodiments of the present invention are generally
directed to medical visualization systems that comprise
combinations of disposable and resuable components, such as
catheters, functional handles, hubs, optical devices, etc. Other
embodiments of the present invention are generally directed to
features and aspects of an in-vivo visualization system that
comprises an endoscope having a working channel through which a
catheter having viewing capabilities is routed. The catheter may
obtain viewing capabilities by being constructed as a vision
catheter or by having a fiberscope or other viewing device
selectively routed through one of its channels. The catheter is
preferably of the steerable type so that the distal end of the
catheter may be steered from its proximal end as it is advanced
with the body. A suitable use for the in-vivo visualization system
includes but is not limited to diagnosis and/or treatment of the
duodenum, and particularly the biliary tree.
Inventors: |
McWeeney; John O.;
(Brighton, MA) ; Morris; Benjamin E.; (Louisville,
KY) ; Robertson; David W.; (Framingham, MA) ;
Freed; David I.; (Westborough, MA) ; Schuerman; James
F.; (Natick, MA) ; Golden; John B.; (Norton,
MA) ; Slanda; Jozef; (Milford, MA) ; Wells;
Brian Keith; (LaGrange, KY) ; Farris, III; Jesse
Leonard; (Andover, MA) ; Chu; Michael S.H.;
(Brookline, MA) ; Carrillo, JR.; Oscar R.;
(Attleboro, MA) ; Hall; Todd A.; (Goshen, KY)
; Chin; Yem; (Burlington, MA) ; Adams; Mark
L.; (Park City, UT) |
Assignee: |
Boston Scientific Scimed,
Inc.
|
Family ID: |
34966138 |
Appl. No.: |
13/443138 |
Filed: |
April 10, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13041624 |
Mar 7, 2011 |
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13443138 |
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11089520 |
Mar 23, 2005 |
7922650 |
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13041624 |
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10914411 |
Aug 9, 2004 |
7922654 |
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11089520 |
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60555356 |
Mar 23, 2004 |
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60656801 |
Feb 25, 2005 |
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Current U.S.
Class: |
600/146 |
Current CPC
Class: |
A61B 1/008 20130101;
A61B 6/06 20130101; A61B 1/00071 20130101; A61B 1/018 20130101;
A61B 1/00103 20130101; A61B 1/0052 20130101; A61B 1/00165 20130101;
A61M 25/0662 20130101; A61B 1/015 20130101; A61B 1/0607 20130101;
A61B 1/00154 20130101; A61B 1/0125 20130101; A61B 1/04 20130101;
A61B 1/07 20130101; A61B 1/307 20130101; A61M 25/0068 20130101;
A61B 1/00135 20130101; A61B 1/00117 20130101; A61M 25/0136
20130101; A61B 1/273 20130101; A61M 25/0147 20130101 |
Class at
Publication: |
600/146 |
International
Class: |
A61B 1/00 20060101
A61B001/00 |
Claims
1-33. (canceled)
34. A medical device system, comprising: an endoscopic device,
comprising: an endoscopic shaft including a steering section, a
working channel, and a viewing channel configured to receive an
optical device; and an endoscopic handle coupled to the endoscopic
shaft and including a steering mechanism configured to move the
steering section; a medical assembly, comprising: an elongate shaft
configured for passage through the working channel, wherein the
elongate shaft includes an articulation section; and a medical
handle coupled to the elongate shaft and including an articulation
mechanism configured to move the articulation section; and a bar
configured to moveably couple the medical assembly to the
endoscopic device to permit relative movement between the medical
handle and the endoscopic handle.
35. The system of claim 34, wherein the bar includes a rigid bar
member extending outward from the endoscopic device.
36. The system of claim 35, wherein the bar member includes a
longitudinal axis fixedly positioned at an angle relative to a
longitudinal axis of the endoscopic handle.
37. The system of claim 36, wherein the longitudinal axis of the
bar member is aligned parallel to a longitudinal axis of the
medical handle.
38. The system of claim 35, wherein the bar member is fixedly
connected to the endoscopic device via a bracket.
39. The system of claim 34, wherein the endoscopic handle includes
a locking mechanism configured to limit movement of the steering
section.
40. The system of claim 34, wherein the endoscopic device further
includes an endoscopic control member connected to the steering
section and the steering mechanism such that movement of the
steering mechanism relative to the endoscopic handle moves the
endoscopic control member and the steering section.
41. The system of claim 34, wherein the medical assembly further
includes an elongate control member connected to the articulation
section and the articulation mechanism such that movement of the
articulation mechanism relative to the medical handle moves the
elongate control member and the articulation section.
42. The system of claim 34, wherein the elongate shaft of the
medical assembly includes at least one channel.
43. The system of claim 34, wherein articulation mechanism includes
a joystick pivotally mounted to the medical handle.
44. The system of claim 34, further including an extension located
between the endoscopic device and the medical handle, wherein the
extension includes a throughbore configured to receive the bar.
45. A medical device system, comprising: an endoscopic device,
comprising: an endoscopic shaft including an steering section, a
working channel, and a viewing channel configured to receive an
optical device; an endoscopic handle coupled to the endoscopic
shaft and including a steering mechanism configured to move the
steering section; and a port in communication with the working
channel; and a medical assembly, comprising: an elongate shaft
configured for passage through the working channel, wherein the
elongate shaft includes an articulation section; a medical handle
coupled to the elongate shaft and including an articulation
mechanism configured to move the articulation section; and wherein
the medical assembly is selectively attached to the port.
46. The system of claim 45, wherein the medical handle has a
longitudinal axis aligned parallel to a longitudinal axis of the
port and the longitudinal axis of the port is positioned at an
angle relative to a longitudinal axis of the endoscopic handle.
47. The system of claim 45, wherein the port includes a rigid
extension tube configured to receive the medical assembly.
48. The system of claim 47, wherein the medical assembly includes a
connector fitting configured for placement within the extension
tube.
49. The system of claim 48, wherein the connector fitting is
located about a proximal region of the elongate shaft.
50. The system of claim 49, wherein the connector fitting has an
outer diameter greater than an outer diameter of the elongate
shaft.
51. The system of claim 48, wherein the connector fitting is
located between the elongate shaft and the medical handle.
52. The system of claim 45, wherein the port is located distal to
the steering mechanism.
53. The system of claim 45, wherein the elongate shaft includes a
flexible segment and a rigid segment located proximal to the
flexible segment.
54. The system of claim 45, wherein the port includes a lumen and
the medical assembly is slidingly attached to the lumen of the
port.
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of prior U.S.
application Ser. No. 10/914,411, filed Aug. 9, 2004. This
application also claims the benefit of U.S. Provisional Application
No. 60/555,356, filed Mar. 23, 2004, and U.S. Provisional
Application No. 60/656,801, filed Feb. 25, 2005. All of the
aforementioned applications are hereby incorporated by
reference.
FIELD OF THE INVENTION
[0002] Embodiments of the present invention generally relate to
medical devices. Several embodiments are generally directed to
medical catheters with steering and/or optical capabilities. Other
embodiments are generally related to medical systems, such as
in-vivo visualization systems, that are suitable for viewing and/or
performing diagnostic and therapeutic modalities within the human
body, such as in the biliary tree.
BACKGROUND OF THE INVENTION
[0003] A challenge in the exploration and treatment of internal
areas of the human anatomy has been adequately visualizing the area
of concern. Visualization can be especially troublesome in
minimally invasive procedures in which small diameter, elongate
instruments, such as catheters or endoscopes, are navigated through
natural passageways of a patient to an area of concern either in
the passageway or in an organ reachable through the passageway.
[0004] Ureteroscopy is one form of procedure that is performed to
diagnosis and treat urinary tract diseases and ureteral strictures.
In conventional ureterscopy, a ureteroscope is inserted retrograde
through the urinary tract such that diagnosis and treatment of
urinary tract abnormalities occur under direct visualization.
Ureteroscopes are typically 7-10Fr. in diameter and include a
sheath that encapsulates a fiber optic element, an illumination
element and a working channel. The working channel allows for the
passage of working devices, such as guidewires, stone retrieval
baskets and lasers. Some ureteroscopes also incorporate a steering
mechanism, which allows the distal tip of the scope to be deflected
by the user in one or more planes. Steering is typically achieved
via manipulation at the handle end of the scope, ex-vivo.
[0005] Problems, however, exist in the use of prior art
ureteroscopes. For example, after each successive urological
procedure, the scope must be cleaned and sterilized before the next
use, which delays successive procedures unless multiple scopes are
purchased. Furthermore, current ureteroscopes are non-disposable
and require extensive, expensive maintenance. Sterilization delays
and costs associated with purchasing and/or repairing scopes have
escalated costs for ureteroscopic procedures and other medical
procedures that utilize similarly configured scopes.
[0006] Detailed information regarding other parts of the anatomy
can be discerned from direct viewing of the anatomy provided
through one or more of the elongate instruments used in other
various medical procedures, such as colonoscopy, upper endoscopy,
bronchoscopy, thoracoscopy, laparoscopy, and hysteroscopy. For use
in these procedures, various types of endoscopes configured for use
in various passageways of the body, such as the esophagus, rectum
or bronchus, can be equipped with direct viewing capability through
the use of optical fibers extending through the length of the
scope, or with digital sensors, such as CCD or CMOS. However,
because endoscopes also provide a working channel through which
other medical instruments must pass, optional lighting bundles and
components to provide steering capability at its distal end, the
scope is typically of a relatively large diameter, e.g., 5 mm or
greater. This large diameter limits the use of the endoscope to
relatively large body lumens and prohibits their use in smaller
ducts and organs that branch from a large body lumen, such as the
biliary tree.
[0007] Typically when examining small passageway such as the bile
duct or pancreatic duct, the endoscope is used to get close to a
smaller passageway or region of concern and another instrument,
such as a catheter, is then extended through the working channel of
the endoscope and into the smaller passageway. Although the
endoscope provides direct visualization of the large body
passageway and entrance to adjoining ducts and lumens, after the
smaller catheter has been extended from the endoscope into the
smaller duct or lumen, direct visualization has heretofore been
limited, and the physician usually relies on radiographical means
to visualize the area of concern or probes blindly.
SUMMARY OF THE INVENTION
[0008] In accordance with aspects of the present invention, a
medical visualization system is provided. The system includes an
endoscope having an endoscope insertion tube extending distally
from an endoscope handle. The endoscope handle has an access port
for accessing an interior lumen of the insertion tube. The
endoscope includes an imaging device for viewing objects located at
the distal end of the insertion tube. The system also includes a
catheter assembly comprising a catheter extending distally from a
catheter handle. The catheter handle is selectively mounted to the
endoscope and has an access port for accessing an interior lumen of
the catheter, wherein the catheter may be inserted into the
endoscope access port and routed through a portion of the insertion
tube interior lumen. The system further includes an optical
assembly comprising an image transmission cable having distal and
proximal ends, wherein the image transmission cable is configured
for insertion into the catheter access port and routable through a
portion of the catheter interior lumen. The optical assembly is
capable of obtaining images located at the distal end of the
catheter and transmitting the images to the proximal end of the
cable.
[0009] In accordance with another aspect of the present invention,
a medical visualization system is provided. The system includes a
disposable catheter having a proximal end and a distal end. The
catheter defines one or more interior lumens that extend from the
distal end to the proximal end. The system further includes a
control handle including an actuation device that effects distal
end catheter deflection. The control handle is functionally
connected to the proximal end of the catheter. The system further
includes a reusable optical assembly that includes an optical
handle and an optical cable extending therefrom. The optical cable
is routable through a portion of the interior catheter lumen from a
position exterior to the catheter.
[0010] In accordance with another aspect of the present invention,
a catheter handle is provided. The catheter handle is suitable for
steering a catheter shaft having a proximal region and a distal
region and at least one steering wire having a distal end region
secured at or near the distal end region of the catheter shaft and
a proximal end. The catheter handle includes a catheter housing
having the proximal end of the catheter shaft attached thereto and
a steering controller carried by the catheter housing and having
the proximal end of the at least one steering wire connected
thereto. The steering controller is movable from a first position
to a second position. The steering controller is capable of
applying tension to the at least one steering wire when the
steering controller moves from the first position to the second
position. The catheter handle further includes a lock mechanism for
retaining the steering controller in the second position to prevent
movement thereof. The lock mechanism includes a lever movable
between an unlocked position and a locked position. The lever is
associated with the steering controller such that movement of the
lever to the locked position restricts movement of the steering
controller.
[0011] In accordance with aspects of the present invention, a
method of bifurcating the interior lumens of a catheter for
connection to one or more fittings is provided. The method includes
obtaining a connector having a central passageway and first and
second branch passageway connected thereto, obtaining a catheter
having first and second interior lumens extending longitudinally
therethrough, and forming first and second openings in the outer
surface of the catheter at selected, spaced locations for accessing
the first and second interior lumens. The location of the first and
second openings correspond to the intersections of the first and
second branch passageways with the center passageway of the
connector, respectively. The method further includes routing the
catheter into the central passageway until the first and second
openings communicate with the first and second branch passageways,
respectively.
[0012] In accordance with another aspect of the present invention,
a method of examining a patient in-vivo is provided. The method
includes providing an endoscope with an insertion tube having at
least one channel. The endoscope has viewing capabilities at the
distal end of the insertion tube. The method also includes
providing a catheter having at least one channel, providing an
imaging device having an image transmission cable, and advancing
the insertion tube into a passageway of a patient under direct
visualization by the insertion tube. The method further includes
advancing the catheter through the insertion tube to a position at
or near the distal end of the insertion tube; and advancing the
image transmission cable through the catheter channel to a position
at of near the distal end of the catheter.
[0013] In accordance with another aspect of the present invention,
a method is provided for cannulating the papilla of a patient. The
method includes providing an optical device having viewing
capabilities, providing an endoscope with viewing capabilities and
at least one channel, and providing a catheter having at least one
channel. The method also includes placing the distal end of the
endoscope into the duodenum of a patient and adjacent to the
papilla and inserting the catheter into the channel of the
endoscope and routing the catheter to the distal end of the
endoscope. The method further includes advancing the optical device
through the catheter channel to the distal end of the catheter; and
advancing the catheter and optical device from the endoscope and
through the papilla under visual inspection of the endoscope.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The foregoing aspects and many of the attendant advantages
of this invention will become more readily appreciated by reference
to the following detailed description, when taken in conjunction
with the accompanying drawings, wherein:
[0015] FIG. 1 is an assembly view of an optical catheter system
according to one embodiment of the invention;
[0016] FIG. 2 is a perspective end view of the distal tip of the
catheter illustrated in FIG. 1;
[0017] FIG. 3 is perspective end view of the distal tip of the
catheter illustrated in FIG. 1, where the sheath of the catheter
has been removed to expose the elongated, internal body of the
catheter;
[0018] FIG. 4 is a cross-sectional view of the elongated body of
the catheter illustrated in FIG. 3, taken along the line 4-4 in
FIG. 3;
[0019] FIG. 5 is a cross-sectional view of an alternative
embodiment of a catheter of the system illustrated in FIG. 1, where
the cross-section is taken along a longitudinal axis of the
catheter;
[0020] FIG. 6 is an assembly view of an optical catheter system
according to another embodiment of the invention;
[0021] FIG. 7 is an assembly view of an optical catheter system
according to a further embodiment of the invention;
[0022] FIG. 8 is a perspective view of one embodiment of a handle
of the optical catheter system illustrated in FIG. 7;
[0023] FIG. 9 is an assembly view of an optical catheter system
according to another embodiment of the invention;
[0024] FIG. 10 is an assembly view of an optical catheter system
according to a further embodiment of the invention;
[0025] FIG. 11 is an assembly view of an optical catheter system
according to an additional embodiment of the invention;
[0026] FIG. 12A is a partial longitudinal cross section view of
another embodiment of a catheter formed in accordance with aspects
of the present invention;
[0027] FIG. 12B is a partial longitudinal cross section view of
another embodiment of a catheter formed in accordance with aspects
of the present invention;
[0028] FIG. 13A is a partial longitudinal cross section view of
another embodiment of a catheter formed in accordance with aspects
of the present invention;
[0029] FIG. 13B is a partial longitudinal cross section view of
another embodiment of a catheter formed in accordance with aspects
of the present invention;
[0030] FIG. 14A is a partial view of one suitable embodiment of a
catheter body constructed in accordance with aspects of the present
invention;
[0031] FIG. 14B is a partial view of one suitable embodiment of a
catheter formed by taking the catheter body of FIG. 14A and
encasing said catheter body with a reinforcement sheath;
[0032] FIG. 14C is a partial view of one suitable embodiment of a
catheter formed by taking the catheter of FIG. 14B and encasing
said catheter with an outer sleeve;
[0033] FIG. 15 is a cross sectional view of the catheter taken
along lines 9-9 in FIG. 14B;
[0034] FIG. 16 is a partial view of the distal end of another
embodiment of a catheter that is suitable for used in the system
illustrated in FIG. 1;
[0035] FIG. 17 is a partial view of the distal end of another
embodiment of a catheter that is suitable for used in the system
illustrated in FIG. 1;
[0036] FIG. 18 is a partial view of the distal end of another
embodiment of a catheter that is suitable for used in the system
illustrated in FIG. 1;
[0037] FIG. 19A is a perspective view of one suitable embodiment of
a catheter assembly suitable for use in an optical catheter
assembly;
[0038] FIG. 19B is a top view of the catheter assembly shown in
FIG. 19A;
[0039] FIG. 19C is a perspective cross section view of the catheter
assembly shown in FIG. 19A;
[0040] FIG. 19D is a top cross section view of the catheter
assembly shown in FIG. 19A;
[0041] FIG. 20 is a planar view of one suitable embodiment of an
optical assembly suitable for use in an optical catheter
assembly;
[0042] FIG. 21 is a partial bottom view of the catheter assembly
shown in FIG. 19A
[0043] FIG. 22 is a cross sectional view of the imaging device
cable of FIG. 20
[0044] FIG. 23A is a side view of the optical handle of FIG.
20;
[0045] FIG. 23B is a side view of the optical handle of FIG. 20
showing the detachable nature of its components;
[0046] FIG. 24 is a perspective view of another catheter handle
formed in accordance with aspects of the present invention;
[0047] FIG. 25 is a top view of another catheter handle formed in
accordance with aspects of the present invention;
[0048] FIG. 26 is a top view of another catheter handle formed in
accordance with aspects of the present invention;
[0049] FIGS. 27A-27B are partial perspective views of a distal
portion of one embodiment of a catheter formed in accordance with
aspects of the present invention, several portions of FIG. 27 is
shown in cross-section;
[0050] FIG. 28 is a perspective view of one embodiment of a
catheter distal end cap formed in accordance with aspects of the
present invention;
[0051] FIG. 29 is a perspective view of another suitable embodiment
of a catheter assembly suitable for use in an optical catheter
assembly;
[0052] FIG. 30 is a cross-sectional view of another embodiment of a
catheter that is suitable for use with the catheter assembly shown
in FIG. 19A;
[0053] FIG. 31 is a front elevational view of one representative
embodiment of an in-vivo visualization system constructed in
accordance with aspects of the present invention;
[0054] FIG. 32 is a lateral cross sectional view of an insertion
tube of an endoscope shown in FIG. 31;
[0055] FIG. 33 is a perspective view of one embodiment of a
catheter assembly constructed in accordance with aspects of the
present invention;
[0056] FIG. 34 is a perspective view of the catheter assembly shown
in FIG. 33 with one housing half removed;
[0057] FIGS. 35A-35C are cross sectional views of suitable
embodiments of a catheter constructed in accordance with aspects of
the present invention;
[0058] FIG. 36A is a partial view of one suitable embodiment of a
catheter body constructed in accordance with aspects of the present
invention;
[0059] FIG. 36B is a partial view of one suitable embodiment of a
catheter formed by taking the catheter body of FIG. 36A and
encasing said catheter body with a reinforcement sheath;
[0060] FIG. 36C is a partial view of one suitable embodiment of a
catheter formed by taking the catheter of FIG. 36B and encasing
said catheter with an outer sleeve;
[0061] FIG. 37 is a cross sectional view of the catheter taken
along lines 39-39 in FIG. 38B;
[0062] FIGS. 38A-38C are cross sectional views of suitable
embodiments of a catheter constructed in accordance with aspects of
the present invention;
[0063] FIGS. 39A-39C are cross sectional views of suitable
embodiments of a catheter constructed in accordance with aspects of
the present invention;
[0064] FIG. 40 is a partial perspective view of a catheter handle
with the control knobs removed to illustrate a lock lever;
[0065] FIG. 41 is a partial cross sectional view of a catheter
handle showing a suitable embodiment of an irrigation port
connected to irrigation lumens of the catheter;
[0066] FIG. 42 is a partial cross section view of the catheter
handle showing the steering mechanism and the optional locking
mechanism;
[0067] FIG. 43A is a front exploded perspective view of components
of the locking mechanism of FIG. 42;
[0068] FIG. 43B is a rear exploded perspective view of components
of the locking mechanism of FIG. 42;
[0069] FIG. 44 is a partial perspective view of the catheter handle
of FIG. 41 illustrating a suitable embodiment of an endoscope
attachment device;
[0070] FIG. 45 is a cross sectional view of one embodiment of a Y
connector formed in accordance with the present invention when
assembled with a catheter;
[0071] FIG. 46A is an end view of a distal end of another
embodiment of a catheter formed in accordance with the present
invention;
[0072] FIG. 46B is a partial side elevational view of the distal
end of the catheter shown in FIG. 46A;
[0073] FIG. 47 is an end view of another embodiment of a catheter
formed in accordance with the present invention; and
[0074] FIG. 48 is an end view of another embodiment of a catheter
formed in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0075] Embodiments of the present invention will now be described
with reference to the drawings where like numerals correspond to
like elements. Embodiments of the present invention are directed to
systems of the type broadly applicable to numerous medical
applications in which it is desirable to insert one or more
steerable or non-steerable imaging devices, catheters or similar
devices into a body lumen or passageway. Specifically, several
embodiments of the present invention are generally directed to
medical visualization systems that comprise combinations of
disposable and resuable components, such as catheters, functional
handles, hubs, optical devices, etc.
[0076] Other embodiments of the present invention are generally
directed to features and aspects of an in-vivo visualization system
that comprises a catheter having a working channel through which a
catheter having viewing capabilities is routed. As will be
described in detail below, the catheter may obtain viewing
capabilities by being constructed as a vision catheter or by having
a fiberscope or other viewing device selectively routed through one
of its channels. The catheter is preferably of the steerable type
so that the distal end of the catheter may be steered from its
proximal end as it is advanced within the body. A suitable use for
the in-vivo visualization system includes but is not limited to
diagnosis and/or treatment of the duodenum, and particularly the
biliary tree.
[0077] Several embodiments of the present invention include medical
devices, such as catheters, that incorporate endoscopic features,
such as illumination and visualization capabilities, for
endoscopically viewing anatomical structures within the body. As
such, embodiments of the present invention can be used for a
variety of different diagnostic and interventional procedures.
Although exemplary embodiments of the present invention will be
described hereinafter with reference to duodenoscopes, it will be
appreciated that aspects of the present invention have wide
application, and may be suitable for use with other endoscopes
(e.g., ureteroscopes) or medical devices, such as catheters (e.g.,
guide catheters, electrode catheters, angioplasty catheters, etc.).
Accordingly, the following descriptions and illustrations herein
should be considered illustrative in nature, and thus, not limiting
the scope of the present invention. Additionally, the catheter with
vision capabilities may be utilized alone, as well as in
conjunction with a conventional endoscope.
[0078] FIG. 1 illustrates an optical catheter system 8 in
accordance with one embodiment of the present invention. The
primary components of the system 8 include a sterile, single-use,
disposable catheter 10, a sterile, single-use, disposable hub 20,
and a reusable handle 30. In the illustrated embodiment, the hub 20
is integral, i.e., permanently part of, the disposable catheter 10
such that they together define a sterile, single-use, disposable
catheter assembly. For example, the hub 20 may be joined to the
catheter 10 with injection molding or adhesive bonding. The
catheter assembly defined by the hub 20 and catheter 10 is
preferably packaged in a sterile container or package (not
illustrated) prior to use by a physician. In an alternative
embodiment, the hub 20 is integral, i.e., permanently part of, the
handle 30. In a further embodiment, the hub 20 is not integral with
the catheter 10 or the handle 30, but connects to these items with
connectors, such as male and female threaded connectors, quick lock
connectors, bayonet connectors, snap connectors, or other known
connectors.
[0079] As is illustrated in FIGS. 2-4, the catheter 10 includes an
elongated, preferably cylindrical, body 38 that extends the entire
length of the catheter 10. In one embodiment, the catheter body 38
has an outer diameter between approximately 5 and 12 French, and
preferably between approximately 7 and 10 French. The catheter body
38 may be constructed from any suitable material, such as
Pebax.RTM. (polyether block amides), nylon, polytetrafluoroethylene
(PTFE), polyethylene, polyurethane, fluorinated ethylene propylene
(FEP), thermoplastic elastomers and the like, or combinations
thereof. The body 38 may be formed of a single material using known
techniques in the art, such as extrusion, or multiple materials by
joining multiple extruded sections by heat bonding, adhesive
bonding, lamination or other known techniques (e.g., juxtaposed
Nitinol tubes wrapped with an adhesive bonding.
[0080] In some applications, e.g. urological, it is desirable that
the catheter 10 have a varying degree of stiffness from the distal
(e.g., renal pelvis) end 18 towards the proximal (e.g., bladder)
end 16. The proximal end 16 should be stiff enough for the device
to advance in the tract to the desired location (e.g., in the
urinary tract to the renal pelvis/kidney area). The distal end 18
should be soft enough to provide a reduction in trauma during
insertion but rigid enough to provide adequate support during the
procedure and prevent collapse or kinking. According to an
embodiment of the present invention for urological application, the
distal portion of the catheter (approximately 1-2 inches where the
flexing occurs) is made more flexible (i.e., less stiff) than the
remainder of the catheter to allow for steerability of the catheter
in vivo. Several techniques for constructing a catheter having a
more flexible distal portion than the remainder of the catheter
will be described in more detail below.
[0081] In the embodiment shown in FIG. 1, the catheter 10 includes
a proximal portion 42 that extends the majority of the catheter 10
and a distal portion 44. The catheter 10 preferably varies in
stiffness between the proximal portion 42 and the distal portion
44. More preferably, the proximal portion 42 is stiffer than the
distal portion 44. This allows the catheter 10 to be easily
advanced without compressing and with minimal twisting while
providing deflection capabilities to the distal portion 42 for
deflecting the distal end 18. In one embodiment, the proximal
portion 42 has a durometer value between 35 and 85 shore D,
preferable 60-80 shore D, and the distal portion 44 has a durometer
value between 5 and 55 shore D, preferable 25-40 shore D.
[0082] As is illustrated in FIGS. 2 and 3, the catheter 10 may
optionally include an inner sheath 56 and/or an outer sleeve 58
that encase the length of the elongated body 38 or portions
thereof. In one embodiment, the sheath 56 is a woven or layered
structure, such as a braided design of fine wire or polymeric
elements woven or coiled together along the longitudinal axis of
the catheter with conventional catheter braiding (e.g., 2 wires
having a diameter ranging from 0.001 to 0.010 inches wound in a
2-over, 2-under helical fashion from the proximal to distal end of
the catheter 10). This allows the catheter 10 to be advanced to the
desired anatomical site by increasing the column strength of the
assembly while also increasing the torsional rigidity of the
catheter. Conventional coiled polymer or braid wire may also be
used for this component with coil wire dimensions ranging in width
from 0.002 to 0.120 inches and thickness from 0.002 to 0.10 inches.
Braided ribbon wire (e.g., 0.002.times.0.005 inches;
0.003.times.0.012 inches) may also be used for the sheath 56.
[0083] The outer sleeve 58 may comprise of any number of polymer
jackets that are laminated over the first sheath 56. Suitable
materials for the sleeve 58 include, but without limitation,
polyethylene, such as polyethylene having a molecular weight in the
range of 50,000 to 100,000; nylon, such as nylon 12, nylon 4-6, and
nylon 6-6; Pebax (polyether block amides); polyurethane;
polytetrafluoroethylene (PTFE), particularly fluorinated ethylene
propylene (FEP) copolymers; and polyethylene impregnated with PTFE.
The outer sleeve 58 may be used to vary the stiffness of the
catheter, if desired, or to provide improved torque transfer and/or
other desirable catheter properties. Additionally, the sleeve 58
may be used as one convenient method for securing a more flexible
deflection section to the proximal section, as will be described in
detail below. In one embodiment, as will be described in more
detail below, the outer sleeve 58 is coextruded, coated, or
otherwise attached once the sheath 56 is applied, to lock the
sheath 56 in place and secure it to the catheter body 38, thereby
forming a composite catheter.
[0084] In several embodiments, the external surface of the
catheter, for example, the outer sleeve 58, can have a hydrophilic
coating or a silicone coating to ease the passage of the device in
vivo. Such a hydrophilic coating can be, for example, but without
limitation, N-Vinyl Pyrrolidone, Poly Vinyl Alcohol, and Poly Vinyl
Pyrrolidone. The hydrophilic coating can be accomplished by coating
the device with a primer, such as Bayhydrol 110 (an anionic
dispersion of an aliphatic polyester urethane resin in
water/n-methyl-2pyrrolidone) and then bonding a primary layer over
the primer. The primary layer can be, without limitation, an
acrylamide or a polyurethane-based acrylamide. Alliphatic polyether
and polyester polyurethanes also can be used as lubricous
coatings.
[0085] In a further embodiment, the distal portion 44 of the
catheter 10 may contain a preset curve detail that allows a
physician to easily access various locations (e.g., the renal
pelvis) with minimal manipulation via passive deflection (i.e.,
without ex-vivo steering mechanism actuation). In one embodiment,
the durometer of the sleeve 58 varies from 35 Shore D to 85 Shore D
(preferably in the region of 70-80D) at the proximal end 16 to 20
Shore D to 55 Shore D (preferably in the region of 30-43D) at the
distal end 18. Curves of various shapes and geometries may be
preset to the distal portion 44 of the catheter 10 as desired. For
example, these curves may be pre-baked into the sleeve 58 at an
elevated temperature below the melting point of the polymer. This
pre-baked curve can vary between 10 and 270 degrees from vertical,
depending upon the specific application of the system 8. To insert
the catheter 10, the curve should be such that when a dilator or
stiff guidewire is inserted into a working channel of the catheter
10 (described below), the curve is straight, while once the dilator
or guidewire is removed, the distal portion 44 reverts to the
pre-baked curve providing access to a desired location. In one
embodiment, the distal portion 44 of the sleeve 58 has a radiopaque
marker band 46 mounted thereon to provide confirmation of the
location of the distal end 18 via fluoroscopy.
[0086] Referring now to FIGS. 2-4, the elongated body 38 of the
catheter 10 defines a working channel 60 that extends the entire
length of the catheter and allows for the passage of various
treatment or diagnostic devices, such as guide wires, stone
retrieval baskets, lasers, biospy forceps etc. The working channel
60 preferably has a diameter sufficient to accept up to a 4 French
working device, such as a retrieval basket device or biopsy
forceps. The elongated body 38 of the catheter 10 may also include
additional channels 62, for use, e.g., as irrigation/insufflation
channels or additional working channels for one or more of the
instruments mentioned above. The channels 62 each extend the entire
length of the catheter 10 and, like the working channel 60, allow
the passage of devices, liquids and/or gases to and from the
treatment area. The channels 62 each have a diameter similar to or
smaller than main working channel 60. In one embodiment, the
channels 62 each have a diameter of about 0.020 inches. The
catheter may also include a channel 64 that extends the entire
length of the catheter through which a fiberscope, fiber optic
cables or other small diameter imaging devices (e.g., 0.25 mm-1.5
mm diameter) can be routed to the distal end of the catheter 10. It
will be appreciated that one or more of the channels 62 may be
eliminated or dimensioned to accommodate the necessary diameter
needed for the working channel 60 and optic lumen.
[0087] As is illustrated in FIGS. 2-4, the catheter 10 also
includes a pair of control or steering wires 68 that cause a distal
portion 44 of the catheter 10 to deflect in one or more directions
as indicated by the dashed lines in FIG. 1. The steering wires 68
are located on opposite sides of the catheter 10 and slide within
grooves 70 in opposite sides of the elongated body 38. In other
embodiments, the steering wires 68 may reside in the sheath 56 or
outer sleeve 58. In yet another embodiment, the steering wires 68
may be routed through dedicated steering wire lumens in the
catheter. The steering wires 68 extend from the distal end 18 of
the catheter 10 to the opposing, proximal end 16 of the catheter
10, and then through the hub 20. The steering wires 68 may be
attached to the distal end 18 of the catheter 10 in a conventional
manner, such as adhesive bonding, heat bonding, crimping, laser
welding, resistance welding, soldering or other known techniques,
at anchor points such that movement of the wires causes the distal
end to deflect in a controllable manner. In one embodiment, the
steering wires 68 are attached via welding or adhesive bonding to a
fluoroscopy marker band 46 (see FIG. 1) fixedly attached to the
distal end. In one embodiment, the band may be held in place via
adhesive and/or an outer sleeve, as will be described in more
detail below. The steering wires 68 preferably have sufficient
tensile strength and modulus of elasticity that they do not deform
(elongate) during curved deflection. In one embodiment, the
steering wires are made from 304 stainless steel with an 0.008 inch
diameter and have a tensile strength of approximately 325 KPSI. The
steering wires 68 can be housed in a PTFE thin-walled extrusion
(not shown) to aid in lubricity and prevent the catheter 10 from
binding up during deflections, if desired.
[0088] In the illustrated embodiment shown in FIG. 1, the steering
wires 68 terminate in a wire connector 70, which may also be part
of the hub 20. The wire connector 70 is a mechanical device that
provides a detachable, preferably quick-fit, connection between the
steering wires of the catheter 10 and the controller 74 or handle
steering wires (not illustrated) associated with the handle 30.
Various types of detachable mechanical connectors, such as joints
and linking elements, are capable of forming a connection that
allows active deflection of the wires 68 via the controller 74 of
the handle 30. In the illustrated embodiment, the catheter 10
includes two steering wires 68 that controllably steer the catheter
distal end 18 within one plane. In alternative embodiments, the
catheter 10 includes additional wires that allow a user to steer
the distal end 18 in multiple planes. In a further embodiment, the
catheter 10 only includes one control wire that allows the user to
steer the distal end 18 in one direction. In another embodiment,
such as described below, the steering wires 68 are not part of the
catheter 10. In such an embodiment, the catheter can be advanced
over a guidewire (not shown) pre-placed in the region of
interest.
[0089] Referring now to FIG. 5, there is shown a cross-sectional
view of an alternative embodiment of a catheter 510 suitable for
use with the optical catheter system 8. The catheter 510
illustrated in FIG. 5 also includes additional features and
inherent functions, as described further below. Unlike the catheter
10, the catheter 510 has one large lumen 512 as opposed to multiple
lumens. This is referred to as a "loose tube" configuration. The
steering wires 568 run along the inner diameter of the catheter 510
to the distal end and are located within channels defined by an
internal sleeve or liner 547. The liner 547 has a low co-efficient
of friction to facilitate the passage of working devices through
the catheter during surgery. The liner 547 has a wall thickness
from 0.0005 to 0.010 inches and is preferably formed from nitinol
tubing, a polymer containing a degree of fluoroethylene such as,
but not limited to, FEP, PTFE or PTFE impregnated thermoplastic
elastomers like Pebax or is formed from a polymer having
fluroethylene combined with thermoplastic materials such as
polyamides, polyurethane, polyethylene and block co-polymers
thereof. The optical assembly, any working devices, and any
irrigation tubes pass through the lumen 512 and connect with the
hub as described above and below. In an alternative embodiment, the
elongated body 538 of FIGS. 2-4 passes through the lumen 512, where
the elongated body 538 routes any working devices, the optical
assembly, and any irrigation tubes as described above.
[0090] The catheter 10 may be constructed in many different ways to
achieve the desired result of a catheter having varying stiffness
along its length, a few of which will now be described in more
detail. FIG. 12A is a longitudinal cross-section view of one
embodiment of a catheter 1210 constructed in accordance with
aspects of the present invention. As best shown in FIG. 12A, the
catheter 1210 comprises a catheter body 1238 that is constructed
with discrete proximal, deflection, and distal tip sections 1282,
1284, 1288. In this embodiment, the proximal section 1282 is
stiffer than the deflection section 1284. Each section may be
constructed in any suitable manner, such as extrusion or milling,
with any suitable materials, such as polyethylene, nylon,
Pebax.RTM. (polyether block amides), polyurethane,
polytetrafluoroethylene (PTFE), thermoplastic elastomers, chosen
for the desired application. The sections 1282, 1284, and 1288 are
then coupled together to form an integral body by encasing the
length of the body 1238 or portions thereof with an outer sleeve
1258. The deflection section may contain one or both of section
elements 1284 and 1288 to impart the required deflection at the
distal end to the system. The outer sleeve 1258 may comprise one of
any number of polymer jackets that are laminated, co-extruded, heat
shrunk, adhesive bonded, or otherwise attached over the catheter
body 1238. Suitable materials for the sleeve 1258 include, but are
not limited to, polyethylene, nylon, Pebax.RTM. (polyether block
amides), polyurethane, polytetrafluoroethylene (PTFE), and
thermoplastic elastomers to name a few. It will be appreciated that
the sections 1282, 1284, and 1288 may also be heat bonded or
adhesive bonded prior to outer sleeve attachment.
[0091] The catheter 1210 may optionally include an inner
reinforcement sheath 1256, for example, a metallic braid, disposed
between sections 1282, 1284, and 1288 of the elongated body 1238
and the outer sleeve 1258, as best shown in FIG. 12B. The
reinforcement sheath 1256 encases the length of the catheter body
1238 or portions thereof. In one embodiment, the reinforcement
sheath extends from the proximal end of the catheter body to
proximal an optional radio opaque band (not shown) at the distal
tip section. The reinforcement sheath increases the kink resistance
of the deflecting section 1284 to ensure that internal lumens
remain patent during bending.
[0092] FIG. 13A is a longitudinal cross section view of another
embodiment of a catheter 1310 constructed in accordance with
aspects of the present invention. As best shown in FIG. 13A, the
catheter 1310 defines a proximal section 1382, a deflection section
1384, and a distal tip section 1388. The catheter 1310 comprises a
catheter body 1338 and an outer sleeve 1358. The catheter body 1338
is a unitary core that is formed, preferably by extrusion, with one
suitable material, such as nylon, Pebax.RTM., PTFE, etc. In one
embodiment, the body 1338 is a PTFE extrusion. When assembled, the
outer sleeve 1358 encases the length of the elongated body 1338 or
portions thereof. The outer sleeve 1358 comprises a number of
polymer jackets 1358A, 1358B, and 1358C that are laminated,
co-extruded, heat shrunk, adhesive bonded, or otherwise attached
over sections 1382, 1384, and 1388 respectively, of the catheter
body 1338. The stiffness value of each jacket is specifically
selected to achieve the desired results, and may vary upon
different catheter applications.
[0093] In one embodiment, the jacket 1358A, which corresponds to
the proximal section 1382, is constructed of a material having a
greater stiffness value than the jacket 1358B, which corresponds to
the deflection section 1384. Suitable materials for the sleeve 1358
include, but are not limited to, polyethylene, nylon, Pebax.RTM.
(polyether block amides), polyurethane, polytetrafluoroethylene
(PTFE), to name a few. If PTFE is chosen for the body 1338, it may
be necessary to etch or otherwise prepare its outer surface to
promote suitable adhesion of the outer sleeve 1358.
[0094] The catheter 1310 may optionally include an inner
reinforcement sheath 1356, for example, a metallic braid, disposed
between the elongated body 1338 and the outer sleeve 1358, as best
shown in FIG. 13B. The reinforcement sheath encases the length of
the elongated body 1338 or portions thereof. In one embodiment, the
reinforcement sheath extends from the proximal end of the catheter
body to proximal an optional radio opaque band (not shown) at the
distal tip section. The reinforcement sheath increases the kink
resistance of the deflecting section to ensure that internal lumens
remain patent during bending.
[0095] FIGS. 14A-14C and 15 illustrate another embodiment of a
catheter 1410 constructed in accordance with aspects of the present
invention. As best shown in FIG. 14A, the catheter includes a
catheter body 1438 having a proximal section 1482, a deflecting
section 1484, and a distal tip section 1488. In one embodiment, the
proximal section 1482 is constructed of a material that is stiffer
than the deflecting section 1484. The proximal section 1482 and the
deflecting section 1484 may be extrusions constructed from any
suitable material, such as polyethylene, nylon, Pebax.RTM.
(polyether block amides), polyurethane, polytetrafluoroethylene
(PTFE), and thermoplastic elastomers, to name a few. In one
preferred embodiment for urological application, the proximal
section is a multi-lumen, PTFE extrusion approximately 200 to 220
cm in length, and the deflecting section 1484 is a multi-lumen,
Pebax.RTM. extrusion approximately 2 to 10 cm in length. The
deflection section 1484 may be coupled to the proximal section 1482
via suitable adhesive or joined by other techniques. The distal tip
section 1488 may be coupled to the distal end of the deflection
section 1484 via suitable adhesive. The distal tip section 1488 may
be constructed of any suitable material, such as stainless steel or
engineering plastics, including but not limited to polyethylene,
nylon, Pebax.RTM. (polyether block amides), polyurethane,
polytetrafluoroethylene (PTFE), and thermoplastic elastomers. The
catheter body 1438 may also include a radio opaque marker band 1446
that encircles a portion of the distal tip section 1488.
[0096] The catheter 1410 (see FIG. 14B) also includes a
reinforcement sheath 1456 that extends from the proximal end of the
catheter to or immediately proximal of the radio opaque marker band
1446. The sheath 1456 may be a woven or layered structure, such as
a braided design of fine wire or polymeric elements (0.001 inches
to 0.010 inches in diameter) woven or coiled together along the
longitudinal axis of the catheter with conventional catheter
braiding techniques. This allows the catheter to be advanced to the
desired anatomical site by increasing the column strength of the
assembly while also increasing the torsional rigidity of the
catheter. The reinforced catheter body shown in FIG. 14B is then
encased by an outer sleeve 1458 comprising of one or more sleeve
sections 1458A, 1458B, and 1458C, having the same or different
stiffness values, as best shown in FIG. 14C, to form the catheter
1410.
[0097] Returning to FIG. 14A, the catheter also includes a
plurality of steering wires 1468 that extend through grooves or
slots formed in the catheter body from the proximal end of the
catheter past the deflecting section 1484. In one embodiment, the
steering wires 1468 terminate at the radio opaque marker band 1446
to which the steering wires 1468 are joined by adhesive bonding,
laser welding, resistance welding, soldering or other known
techniques.
[0098] In several embodiments, it is preferable for the steering
wires to be encased with a laminate structure 1496 for allowing the
steering wires 1468 to move freely within or along the catheter
body, and thus, make the mechanics of actuation as smooth as
possible. As best shown in FIG. 15, the laminate structure 1496 is
formed by outer jacket 1497 constructed of a thermoplastic polymer,
such as polyurethane, Pebax.RTM., thermoplastic elastomer etc.
which encases an inner reinforcement member 1498, such as a
metallic braid (e.g., stainless steel braid having, for example, a
0.0015''.times.0.006'' helically wound). Inside the reinforcement
member 1498, is a layer 1499 of a friction reducing material, such
as PTFE or FEP tubing, over which the aforementioned layers are
formed. The laminate structure 1496 begins at the proximal section
1482 and extends to just proximate the radio opaque marker band
1446, as best shown in FIG. 14A.
[0099] As was described above, in several embodiments of the
catheter, it is desirable for the deflection section or distal
portion to be configured to deflect more easily than the proximal
section or portion. In one embodiment, the deflection section or
distal portion has a durometer value less than the proximal
section. In other embodiments, the flexibility may be varied
gradually (e.g., increasingly) throughout the length of a catheter
tube from its proximal end to its distal end. In other embodiments,
the deflection section may be an articulating joint. For example,
the deflection section may include a plurality of segments that
allow the distal section to deflect in one or more directions. For
examples of articulation joints that may be practiced with the
present invention, please see co-pending U.S. patent application
Ser. Nos. 10/406,149, 10/811,781, and 10/956,007, the disclosures
of which are hereby incorporated by reference.
[0100] Other mechanical joints or configurations may be utilized
that allow the distal portion of the catheter to flex or bend in
one or more directions more easily. Turning now to FIG. 16, there
is shown one embodiment of a catheter 1610 formed in accordance
with aspects of the present invention. FIG. 16 shows a partial view
of the distal portion 1646 of a catheter 1610 constructed from a
metal or plastic tube with slots 1694 cut 180 degrees and spaced an
even distance apart to form a deflecting section. The slots will
allow the catheter 1610 to deflect in two directions or in a single
plane at the distal end 1618. The proximal section of the tube is
not slotted and may be used as the non-deflecting portion of the
catheter. If preferred, the slotted section may be used in
embodiments discussed above. The slotted section can be useful when
the catheter profile is not symmetrical or is irregular. It will be
appreciated that the slots 1694 can be V-shaped, semi-circle, wave
or any preferred configuration.
[0101] FIG. 17 illustrates another embodiment of a catheter 1710
having a deflectable distal portion. In this embodiment, the
catheter is constructed from a very flexible plastic extrusion with
multiple lumens. The two main lumens, the working channel 1760 and
the optical assembly channel 1762, are reinforced with coils 1796
to minimize out-of plane deflection. As shown in FIG. 17, the
center of both lumens and both coils lie on the Y-axis to provide
less resistance against deflection in the x-plane. When the
steering wires (not shown) are pulled along the direction of the
steering wire slots, the catheter will tend to bend about the
y-axis or in the x plane. The coils 1796 also prevent the lumen
from kinking as the catheter deflection radius becomes tighter. The
catheter 1710 may further include an outer braid and outer layer,
as described in detail above.
[0102] FIG. 18 illustrates yet another embodiment of a catheter
1810 having a flexible distal portion 1846. In this embodiment, the
multiple lumen extrusion is preferred to be flexible. Slots 1894
are cut on both sides of the extrusion to assist and bias the
catheter 1810 in the preferred direction of deflection. As was
described above, coils 1896 may be used to support the main lumens,
if preferred, but are not required. The coil or coils can be useful
if the slot cuts are deep to penetrate the main lumens. The coils
could be used to line the lumens such that the devices do not
inadvertently get caught against the slots. The catheter may
further include a braided sheath and outer sleeve, as described
above.
[0103] Returning now to FIGS. 1-4, the elongated body 38 of the
catheter 10 includes a lumen 64 that holds an optical assembly 40
or portions thereof, as described briefly above. The optical
assembly 40 is defined, e.g., by a cylindrical, elongated tubular
member 24 and optic bundles 32, 34. The optical assembly 40 permits
a user of the system 8 to view objects at or near the distal end 18
of the catheter 10. In the illustrated embodiment, the distal end
18 of the catheter includes a clear lens or window 22 that
sealingly encloses the distal end of the lumen 64 to protect the
optic bundles 32, 34 inside the lumen 16. The member 24 defines
multiple lumens 26 that each contain one fiber optic bundle 32, 34.
The first fiber optic bundle 32 illuminates the area or objects to
be viewed, while the second fiber optic bundle 34 communicates the
illuminated image to an eyepiece or ocular lens device 36 located
at the handle 30 through which a user can view the images
communicated via the fiber optic bundle. The handle 30 can also be
configured to connect to a camera or imaging system such that users
can save images and view them on a display. The fiber optic bundles
32, 34 each comprise one or more fiber optics cables, preferably
multiple fiber optical cables, but may also include lenses, rods,
mirrors, hollow or solid light guides, etc. The bundles 32, 34 are
attached to the lens 22 with a clear adhesive, bond, or other
connection, but can also abut the lens or be located adjacent the
lens without any attachment. In an alternative embodiment, the lens
22 is not attached to the distal end 18 of the catheter, but is
instead attached directly to the elongated member 24 and fiber
optic bundles 32, 34.
[0104] As will be appreciated, the optical components of the
catheter 10 may take many other forms and configurations. For
example, the lumen 64 can include one fiber optic bundle for
communicating images and one or more single illumination fibers
that are not fixed relative to each other by the elongated member
24. That is, the fibers can be freely located in the lumen 64.
Additionally, the elongated member 24 can have more or less lumens
26 that contain more or less fibers and/or bundles for illuminating
and/or communicating images. For example, in an alternative
embodiment, a single fiber replaces one or both of the bundles 32,
34. Furthermore, the elongated body 38 need not include the lumen
64. For example, one or more optical fibers or bundles of fibers
can be molded in the elongated body 38. Alternatively, the
elongated body 38 may include two lumens 64 for receiving separate
fiber optic bundles 32 and 34, respectively. Possible alternative
known configurations for the optical assembly 40 are described in
U.S. Pat. Nos. 4,782,819; 4,899,732; 5,456,245; 5,569,161; and
5,938,588, the entire disclosures of which are hereby incorporated
by reference.
[0105] In the illustrated embodiment, the tubular optical assembly
40 is part of the disposable catheter assembly defined by the
catheter 10 and hub 20. Hence, the tubular optical assembly 40 and
its fiber optic bundles 32, 34 extend from the distal end 18 of the
catheter 10 to the opposing, proximal end 16 of the catheter 10,
and then through the hub 20. As is illustrated in FIG. 1, the hub
20 includes a fiber optic connector 72 in which the fiber optic
bundles 32, 34 terminate. The fiber optic connector 72 is a
mechanical device that provides a detachable optical connection
between the fiber of the optical assembly 40 and the fiber or lens
system of the handle 30. Thus, the optical assembly 40 extends
continuously through the disposable catheter 10 and hub 20, without
interruption, to the fiber optic connector 72. In one embodiment,
the fiber optic connector 72 is a detachable, simple point-to-point
connection or splice. In other embodiments, the connector 72 is a
more complex design having multi-port or other types of optical
connections. For example, the connector 72 can be configured to
redistribute (combine or split) optical signals, such as with an
active or passive fiber optic couplers, e.g., splitters, optical
combiners, X couplers, star couplers, or tree couplers. The fiber
optic connector 72 can also include a micro lens,
graded-refractive-index (GRIN) rods, beam splitters, and/or optical
mixers, and may twist, fuse, and taper together the fiber optic
bundles 32, 34. In other embodiments, such as those described
below, the optical assembly 40 is not part of the disposable
catheter 10.
[0106] Referring again to FIG. 1, the handle 30 is generally an
endoscopic handle that connects to the connectors 70, 72 of the hub
20 such that a user of the system can view images communicated by
the fibers of the catheter 10 and such that a user can controllably
steer or deflect the distal end 18 of the catheter. The handle 30
includes one or more shafts 78 that connect to and interact with
the fiber optic connector 72 and the wire connector 70. The handle
30 also includes a controller or actuator 74 by which a user can
steer the distal end 18 of the catheter 10. In the illustrated
embodiment, the handle 30 generally includes a pair of steering
wires (not illustrated), each of which is associated with one of
the steering wires 68 of the catheter 10. The wires of the handle
30 are connected to the controller 74 at one end and are connected
at the other end to the wires 68 via the connector 70. To steer the
catheter 10, a user actuates the controller 74, which causes the
wires 68 to deflect, which in turn forces the distal end 18 of the
catheter to deflect as illustrated in FIG. 1. In the illustrated
embodiment, the controller 74 is a user-operated mechanical slide
or rotatable lever that is adapted to pull and release the wires 68
connected to the handle 30 by the connector 70. In an alternative
embodiment, the controller 74 may take other forms, such as a
rocker arm or rotating knob, adapted to pull and release the wires.
In another alternative embodiment in which the catheter 10 has two
or more pairs of steering wires, the handle 30 includes additional
actuators and corresponding controls to drive the additional pairs
of steering wires. In one embodiment, the handle 30 includes a
locking mechanism, such that when a curve is activated by the
controller 74, the curve may be locked in place. The use of wires
to steer a tip of a catheter is well-known. Suitable examples are
set forth in U.S. Pat. Nos. 4,899,723; 5,273,535; 5,624,397;
5,938,588, 6,544,215, and International Publication No. WO 01/78825
A2, the entire disclosures of which are hereby incorporated by
reference.
[0107] As is described above, the handle 30 includes steering wires
and fiber optics that connect to the steering wires 68 and fiber
optic bundles 32, 34 of the catheter 10 via the connectors 70, 72.
As will be appreciated, the handle 30 may be battery powered or
connect to a power supply. The handle 30 also includes a light
source, or connects to a light source, that illuminates the fiber
bundle 32. In addition, the handle 30 has an eyepiece 80 for a user
to view an image transmitted by the image bundle 34 from the distal
end 18.
[0108] Referring again to FIG. 1, the hub 20 also includes
connectors or ports 50 that each communicate with one of the lumens
62 of the catheter 10, as well as a connector or port 52 that
communicates with the working channel 60. The connectors 50, 52 are
preferably integral with the hub 20 and thus are disposable with
the hub 20 and catheter 10. In the illustrated embodiment,
connector 72 is separate from the connector 70 and connects to two
separate portions, shafts, or projections of the handle 30. In an
alternative embodiment, the connectors 70 and 72 are combined into
a single connector that interfaces with a single portion of the
handle 30, such that the optics handle and actuator for steering
are disconnectable as a unit and reusable.
[0109] In a further embodiment of a system 608 in which the
connectors 670 and 672 are separate connectors, such as is
illustrated in FIG. 6, the optical catheter system 608 includes a
first handle 630A that steers the catheter 610 and a second handle
or component 630B having the eyepiece 680 through which the user
can view images communicated by the catheter optics. In this
embodiment, the first handle 630A connects to the connector 670 and
the second handle 630B connects to the connector 672 to couple and
decouple from the fiber bundle in the catheter 610. The handle 630A
may be disposable, while the handle 630B is reusable. The handle
630B includes a sleeve 682, such as an extrusion over the fiber
optic/illumination fiber component of the handle, to protect fiber
sterility and prevent damage during the procedure due to the
miniature nature of the fiber.
[0110] As will be appreciated from the foregoing, the optical
catheter system 8 (See FIG. 1) in accordance with one embodiment of
the present invention includes a sterile, single-use, disposable
optical catheter 10, a sterile, single-use, disposable hub 20, and
a reusable handle 30 for viewing images and steering the catheter.
Because the catheter 10 and hub 20 are disposed of after a
procedure, delays and costs associated with cleaning, sterilizing,
and maintaining conventional scopes are avoided.
[0111] Set forth below is a description of an exemplary clinical
application of the optical catheter system 8 according to the
invention. The sterile single-use catheter 10 and hub 20 are
removed from a factory package and then connected to the reusable
handle 30 via the connectors 70 and 72. A guidewire is advanced
into the urinary tract and the catheter 10 with or without a
dilator is inserted over the guidewire. The guidewire may be
withdrawn. The catheter 10 is then steered with the controller 74
to deflect the distal end 18 to the desired location in the kidney.
The connectors/ports 50 and 52 are then associated with various
working device and irrigation lines, as needed, and the desired
treatment and/or diagnosis are performed. The catheter 10 is then
withdrawn and discarded.
[0112] In an alternative embodiment of the optical catheter system
708 illustrated in FIG. 7, the optical assembly 740 is not attached
to the distal end 718 of the catheter and instead extends from the
distal end 718, through the hub 720, and into the handle 730
without interruption. Additionally, the steering wires 768 extend
from the distal end 718, through the hub 720, and into the handle
730 without interruption. When fully inserted into the catheter
710, the steering wires 768 each attach to the distal end 718 of
the catheter 710 such that movement of the wires causes the distal
end 718 to deflect in a controllable manner. The steering wires 768
attach to the distal end 718 of the catheter with a detachable
connection (not shown), such as a snap or quick lock connection,
that permits the steering wires to be easily detached from the
distal end 718 after use of the catheter such that the wires can be
withdrawn from the catheter. In this embodiment, the system 708
does not include the optical and wire connectors, and the wires 768
and optical assembly 740 are not disposable. That is, the wires 768
and optical assembly 740 are part of the reusable handle 730.
Hence, in this embodiment, the lumens and channels of the elongated
body receive the elongated wires 768 and elongated optical assembly
740 of the reusable handle 730b. The catheter 710 and hub 720 are
still disposable.
[0113] FIG. 8 illustrates an alternative embodiment of a handle 830
suitable for use with an optical catheter system 8. The handle 830
includes an optical portion 686 and a snap-on, slide-on, or clip-on
steering portion 688. The optical portion 686 is the same as that
of the handle 30 (see FIG. 1), but does not include the features
for steering the catheter 10. The steering portion 688 is the same
as that of the handle 30 (see FIG. 1), but does not include the
optical features of the handle 30. The steering portion 688 may be
disposable or reusable. The optical portion 680 is reusable.
[0114] In a further embodiment of the optical catheter system 908
illustrated in FIG. 9, the connectors 970 and 972 are not part of
the hub 920, but are respectively attached to the optical assembly
940 and the steering wires 968. The fibers of the optical assembly
940 are not attached to the distal end 918 of the catheter 910 and,
when inserted into catheter, extend from the distal end 918,
through the hub 920, and terminate at the connector 972, which is
integral with the optical assembly. The reusable handle 930 is
configured to connect directly to the connector 972 of the optical
assembly and functions as described above. When fully inserted into
the catheter 910, the steering wires 968 each attach to the distal
end 918 of the catheter 910 such that movement of the wires causes
the distal end 918 to deflect in a controllable manner. The
steering wires 968 attach to the distal end 918 of the catheter
with a detachable connection, such as a snap or quick lock
connection, that permits the steering wires to be easily detached
from the distal end 918 after use of the catheter such that the
wires can be withdrawn from the catheter. When inserted into the
catheter 910, the wires 968 extend from the distal end 918, through
the hub 920, and terminate at the connector 970, which is integral
with the wires. Hence, the wires 968 and the connector 970 form a
control wire assembly. The handle 930 is configured to connect
directly to the connector 970 of the steering wire assembly and
function as described above. In this embodiment, the optical
assembly 940 (and its connector 972) and the wires 968 (and their
connector 970) are both disposable. The optical assembly 940 and
its connector 972, and the wires 968 and their connector 970 may be
sterilely packaged separately or in combination with the catheter
910.
[0115] FIG. 10 illustrates an additional embodiment of an optical
catheter system 1008 of the present invention. In this embodiment,
the handle 1030 for steering the catheter 1010 is integral with the
hub 1020 and catheter 1010, and are together packaged as a
single-use, sterile, disposable assembly. The optical handle 1030B
and its optical assembly 1040 are reusable. Hence, the optical
assembly 1040 is received by the hub 1020 and catheter 1010 for
use, and then removed therefrom after the procedure has been
performed. The steering wires of the handle 1030A are attached to
the distal end 1018 of the catheter 1010 and extend from the distal
end 1018, through the hub 1020, and into the handle 1030A without
interruption. In this embodiment, the system 1008 does not include
the optical fiber and steering wire connectors, and the optical
assembly 1040 is part of, i.e., integral with, the reusable handle
1030B.
[0116] FIG. 11 illustrates an additional embodiment of an optical
catheter system 1108 of the present invention. In this embodiment,
the handle 1030A for steering the catheter 1110 is integral with
the hub 1020 and catheter 1110, and are together packaged as a
single-use, sterile, disposable assembly. The optical handle 1030B
is reusable and is connectable to the disposable optical assembly
1140 via a connector 1172. Hence, the optical assembly 1140 is
disposable with the integral assembly defined by the handle 1130A,
the hub 1120, and catheter 1110, and may also be packaged with
these items. The optical assembly 1140 is received by the hub 1120
and catheter 1110 for use, removed therefrom after the procedure
has been performed, and then discarded with the handle 1130A, the
hub 1120, and catheter 1110. The optical handle 1130B is reused.
The steering wires of the handle 1130A are attached to the distal
end 1118 of the catheter and extend from the distal end 1118,
through the hub 1120, and into the handle 1130A without
interruption. In this embodiment, the system 1108 does not include
the steering wire connector, and the optical assembly 1140 is not
integral with the reusable handle 1130B.
[0117] FIGS. 19A-19D and 20 illustrate another embodiment of an
optical catheter system constructed in accordance with the present
invention. As best shown in FIGS. 19 and 20, the optical catheter
system includes a sterile, single-use, disposable catheter assembly
1912 (See FIGS. 19A-19D) and a resuable optical system 2040 (See
FIG. 20). The catheter assembly 1912 includes a handle 1930A and a
catheter 1910. The optical system 2040 includes an optical handle
2030B connected to an optical cable 2042. The optical handle 2030B,
in one embodiment, may comprise an image viewing device, such as an
ocular 2080, and a coupler 2084.
[0118] As best shown in FIG. 19, the catheter 1910 is functionally
connected to the catheter handle 1930B. The catheter 1910 may be
any suitable catheter for use in vivo, such as any one of the
catheters described in detail herein. The handle 1930A includes a
handle housing 1932 to which a steering mechanism 1974, optional
lock mechanism 1976, and one or more ports 1958, 1960 are
operatively connected. In one embodiment, the handle housing 1932
comprises an upper, proximal section 1934 and a lower, distal hub
1936. In the embodiment shown in FIG. 19A, the distal hub 1936 of
the handle housing is Y-shaped. The Y-shaped hub 1936 includes a
distal stem section 1938 to which the proximal end 1912 of the
catheter 1910 is functionally connected. The Y-shaped hub 1936
further includes first and second branch sections 1940 and 1942,
the first branch section 1940 is connected to the distal end of the
housing upper section 1934 while the second branch section 1942
includes an opening through which an interior channel of the
catheter, such as the working channel, may be accessed. The first
branch section 1940 may be connected to the upper section 1934 in
such a manner as to permit free or limited rotation of the Y-shaped
hub 1936 with respect to the housing upper section 1934 about a
longitudinal axis of the handle 1930A. In one embodiment, this may
be accomplished by a circular flange (not shown) formed at the
proximal end of the first branch section and being captured in a
cooperating slot (not shown) formed by the distal end of the
housing upper section.
[0119] In one embodiment, handle housing sections are formed by
housing halves 1934A and 1934B and 1936A and 1936B joined by
appropriate removable fasteners, such as screws, or non removable
fastening techniques, such as heat bonding, ultrasonic welding or
adhesive bonding. As best shown in FIG. 19A, the housing halves
(only 1936B is shown) of the Y-shaped hub 1936 define respective
passageways 1948 and 1950 for communicating with the remainder of
the handle housing 1934 and exterior the handle, respectively. The
handle 1930A further includes a bifurcation 1954. The bifurcation
1954 is preferably insert molded to connect the proximal end 1916
of the catheter 1910 and its lumens to the working channel port
1958 and optical assembly port 1960. In embodiments where the
bifurcation 1954 is insert molded, the catheter steering wires 1968
are sleeved with a PTFE sleeve or a metal sleeve or similar coiled
or braided tube such that molten polymer from the bifurcation
process will bond to the sleeve and allow the steering wire within
the sleeve to move respectively therein.
[0120] As was described above, the handle housing 1932 includes one
or more ports 1958 and 1960 for providing access to the respective
channels of the catheter 1910. In the embodiment shown, the ports
include, but are not limited to, a working channel port 1958 and an
optical assembly port 1960. The ports may be defined by any
suitable structure. For example, the working channel port 1958 and
the optical assembly port 1960 may be defined by fittings 1962 and
1964, respectively, such as luer fittings, that may be bonded or
otherwise secured to the handle housing 1932 when assembled. In one
embodiment, the housing halves may define cooperating structure
that securely locks the fittings 1962 and 1964 in place when
assembled. The fitting 1962 and 1964 are connected to the
appropriate catheter channels via tubing 1966, as best shown in
FIG. 19C. In one embodiment, the handle 1930A also includes a loop
hub 1970 interconnected between the optical assembly port 1960 and
the tubing 1966. The loop hub 1970 has an oversized chamber to
allow the optical cable of the optical system to be deflected to
account for the change (shortening) in catheter length when the
distal end of the catheter is deflected by the steering wires
1968.
[0121] The catheter handle 1930A may also include a steering
mechanism 1974, as best shown in FIGS. 19A and 19B. The steering
mechanism 1974 of the catheter handle 1930A controls the deflection
of the distal end 1918 of the catheter 1910. The steering mechanism
1974 may be any known or future developed mechanism that is capable
of deflecting the distal end of the catheter by selectively pulling
one or more steering wires 1968. In the embodiment shown in FIGS.
19A and 19B, the steering mechanism 1974 includes an activation
lever 1980 for effecting 2-way steering of the catheter distal end
in a single plane. By actuating the activation lever 1980 in one
direction the distal end will deflect in one direction. Turning the
activation lever 1980 in the other direction will deflect the
catheter distal end in the opposite direction. It is preferred that
the catheter distal end will travel in a single plane when sweeping
from one direction to the other. The activation lever 1980 is
connected to the distal end 1918 of the catheter 10 via steering
wires 1968 (See FIG. 19C), respectively, that extend through the
catheter 1910. While a manually actuated steering mechanism for
effecting 2-way steering of the distal end is shown, it will be
appreciated that a manually actuated steering mechanism that
effects 4-way steering may be practiced with and is therefore
considered to be within the scope of the present invention.
[0122] Referring now to FIGS. 19A-19D, there is shown one
embodiment of the steering mechanism 1974 that may be practiced
with the present invention. The steering mechanism 1974 includes
the activation lever 1980 secured for rotation with a pulley 1982.
The pulley 1982 is rotatably supported by a boss 1984 integrally
formed or otherwise positioned to extend into the interior of the
handle housing 1932 in a fixed manner from the housing half 1934B.
The pulley 1982 is either integrally formed or keyed for rotation
with the activation lever 1980. The proximal ends of one pair of
steering wires 1968 are connected to opposite sides of the pulley
1982 in a conventional manner. In the embodiment shown, the
steering wires 1968 are placed into respective slots 1986 and
secured thereto by suitable fasteners, such as set-screws 1988.
Each set-screw pinches the steering wires 1968 against the pulley
1982 to secure it in place. When assembled, the pulley 1982
provides control of the distal end 1918 of the catheter 1910 in two
directions. In these embodiments, the catheter 1910 is straight in
the neutral position.
[0123] It will be appreciated that the steering mechanism may be
configured such that the direction of catheter deflection in both
directions is either equal or such that preferential one side
deflection is realized (e.g., 180 degree deflection in one
direction vs. 90 degree deflection in the other, etc.). For equal
directional deflection, the steering wires 1968 are of equal length
when the catheter is in the neutral (i.e., straight or unbent)
position and are attached to the pulley 1982 at positions located
along an axis of the pulley that is perpendicular to the
longitudinal axis of the catheter, as best shown in FIG. 19D. For
unequal angles of deflection, the steering wires are not equivalent
in length and the steering wires are attached to the pulley in
other positions around the circumference thereof. As will be
appreciated, the catheter side related to the side with the greater
steering wire displacement will deflect to the greater angle. In
embodiments where there is only a single deflection of the shaft
required, a single pull wire system may be used. The steering wire
maybe attached to the pulley at a position proximal the
perpendicular axis of the pulley to maximize the full swing of the
pulley.
[0124] In other embodiments, it is also understood that changes
could be made to the design to achieve a mechanical advantage such
as to increase the diameter of the pulley for a longer steering
wire displacement length. Other configurations that achieve a
mechanical advantage may also be used. For example, instead of the
steering wires terminating at the pulley, the steering wires may be
wrapped around pins positioned on the pulley and then anchored on
the handle at points distal the pulley. In this case, the steering
wires will displace up to twice its normal distance when compared
to the device shown in FIG. 19D. This feature may be used for
larger diameter catheter deflection where longer steering wire
displacement is utilized.
[0125] As best shown in FIGS. 19A-19D, the handle 1930A may further
include a lock mechanism 1976 that functions to lock the catheter
1910 in a desired deflection position or apply tension on the
pulley 1982 during use. The lock mechanism 1976 includes a tension
knob 1988 that is actuatable between a locked position, selectively
tensioned positions, and an unlocked position. As best shown in
FIG. 19C, the tension knob 1988 is threaded onto a thread post 1990
extending from the activation lever 1980. The thread post 1990
extends through the handle housing to allow the tension knob 1990
to be externally mounted. In use, by tightening the tension knob
1990 on the thread post 1990 against the handle housing 1932 will
also bring the activation lever 1980 into contact with the other
handle housing half. The user can adjust the tension of the
activation lever 1980, as desired, by rotation of the tension knob
1990. Further tightening of the tension knob 1990 will prevent
rotation of the activation lever 1980, thereby locking the steering
wires 1968 in place, and in turn, locking the deflected position of
the catheter 1910.
[0126] In accordance with another aspect of the present invention,
it may be desirable to adjust the tensioning of the steering wires
after the handle 1930A has been assembled. Turning now to FIG. 21,
there is shown a handle having a tension adjustment assembly 2188
accessible from exterior the housing through a window 2190. The
tension adjustment assembly includes an adjustment screw 2192
cooperatingly engaged with a stationary nut 2194. The nut 2194 may
be held stationary and non-rotatable, for example, via molded
structure in the handle housing. When assembled, the steering wires
1968 are threaded through the longitudinal lumen of the adjustment
screw 2192. The adjustment screw 2192 is designed with teeth on the
side of its head portion to allow a user to rotate the screw.
Rotation of the screw to advance the adjustment screw 2192 in the
direction of arrow A will increase steering wire tension while
rotation of the screw for advancing the screw 2192 in the direction
of arrow B will decrease tension on the steering wires 1968. Proper
tension will allow quicker response of the steering wire to
actuation of the activation lever.
[0127] As was discussed briefly above, a small diameter viewing
device, such as a fiberscope or other imaging device, may be
slidably routed through one channel (e.g., optical assembly
channel) of the catheter 1910 to the distal end thereof. The
viewing device permits the user of the optical catheter assembly to
view objects at or near the distal end or tip of the catheter 1910.
Turning now to FIG. 20, there is shown one suitable embodiment of a
viewing device or optical assembly 2040 formed in accordance with
aspects of the present invention. The optical assembly 2040
includes a fiber optic cable 2072 connected to an optical handle
2030B comprising a coupler 2084 and an ocular or eyepiece 2080. The
fiber optic cable 2072 is defined, for example, by one or more
optical fibers or bundles 2032 and 2034 encased by a cylindrical,
elongated tubular sleeve 2076, as best shown in FIG. 22. The outer
diameter of the fiber optic cable 2072 is preferably between 0.4 mm
and 1.2 mm, although other sizes may be used depending on its
application and the lumen size of the catheter. The tubular sleeve
2076 of the fiber optic cable 2072 may be constructed of any
suitable material, such as nylon, polyurethane, polyether block
amides, just to name a few. Additionally, a metallic hyptotube may
be used.
[0128] In the illustrated embodiment, as best shown in FIGS. 20 and
22, the fiber optic cable 2072 includes one or more centrally
extending coherent imaging fibers or fiber bundles 2034 and one or
more circumferentially extending illumination fibers or fiber
bundles 2032 (which may not be coherent) that generally surround
the one or more imaging fibers of fiber bundles 2034. The fibers or
fiber bundles 2032 and 2034 may be attached to the tubular sleeve
2076 via suitable adhesive. The distal end of the fiber optic cable
2072 includes a distal lens and/or window (not shown) that encloses
the distal end to protect the fiber bundles. Alternatively, the
optical assembly lumen of the catheter 1910 (See FIG. 19) may
include a lens or window positioned at its distal end, as was
described in detail above. The distal lens (not shown) also
projects the image from the field of view onto the distal end of
the image bundle 2034. The image bundle 2034 then transmits the
image from the distal end of cable 2072 to the handle 2030B.
[0129] The optical assembly 2040 may have a stop collar or sleeve
(not shown) to limit movement of the cable 2072 through the optical
assembly channel of the catheter and limit the length by which the
cable 2072 can extend beyond the distal end of the catheter 1910.
The inner surface of the imaging channel of the catheter may have
color markings or other calibration means to indicate to the user
when inserting the cable 2072 that the end of the catheter is
approaching or has been reached.
[0130] The proximal end of the fiber optic cable 2072 is
functionally connected to the coupler 2084 of the handle 2030B. In
use, the illumination fibers or fiber bundles 2032 illuminate the
area or objects to be viewed, while the imaging fibers or fiber
bundles 2034 communicates the illuminated image to an image viewing
device, such as an eyepiece or ocular lens device 2080, connected
to the coupler 2084 through which a user can view the images
communicated via the imaging fibers or fiber bundles 2034. The
eyepiece 2080 may either be permanently or detachably connected to
the coupler 2084 as shown in FIGS. 23A and 23B. In one embodiment,
the eyepiece 2080 is detachably connected via a snap fit connector
2098; however, other selectively detachable connectors may be used,
such as male and female threaded connectors, quick lock connectors,
bayonet connectors, to name a few. In this embodiment, the coupler
2084 and cable 2072 can be detached from the eyepiece 2080 after a
procedure and discarded, while the eyepiece 2080 may be sterilized
and reused. The optical handle 2030B can also be configured to
connect to a camera or imaging system such that users can save
images and view them on display. It will be appreciated that the
handle 2030B may include other known components, such as adjustment
knobs (not shown), that adjust the relative positioning of the
lenses and, thus, adjusts the focus of the image transmitted
through them. The coupler 2084 may also includes a light post 2086
that is connected to the proximal end of the illumination fibers or
fiber bundle 2032. The light post 2086 is configured to be
releasably connected to a light cable for supplying light from a
light source external the optical assembly 2040 to the illumination
fibers or fiber bundle 2032.
[0131] In one embodiment, the optical assembly may optionally
include a contamination sleeve 2090 for protecting fiber sterility
and preventing damage during the procedure due to the miniature
nature of the fiber, as best shown in FIG. 20. The contamination
sleeve 2090 when attached to the handle extends from the coupler
2084 distally to a section of the optical cable 2072. The end of
the contamination sleeve 2090 terminates in a distal connector
2092. The distal connector 2092 is configured to connect to the
optical assembly port of the steering handle 1930A, preferably in a
sealable manner.
[0132] FIG. 24 illustrates another embodiment of a catheter handle
2430 constructed in accordance with aspects of the present
invention that is suitable for use with the catheter 1910 described
above and shown in FIG. 19A. The catheter handle 2430 is
substantially similar in construction, materials, and operation as
the catheter handle 1930A described above and shown in FIGS.
19A-19D, except for the differences that will now be described. As
best shown in FIG. 24, the distal hub section 2436 of the handle
housing 2432 is not formed as a Y-shaped distal hub but instead is
formed as a tapering cylindrical body. In this embodiment, both
working channel and optical channel ports/luer connectors 2458-2460
are located at the proximal end of the handle housing 2432. The
connectors 2458 and 2460 are connected in communication with the
respective catheter channels via tubes (not shown). Since the
Y-shaped distal hub is not required in this embodiment, the entire
handle housing can be formed by two molded housing halves.
[0133] FIG. 25 illustrates another embodiment of a catheter handle
2530 constructed in accordance with aspects of the present
invention that is suitable for use with the catheter 1910 of FIG.
19A. The catheter handle 2530 is substantially similar in
construction, materials, and operation as the catheter handle
described above and shown in FIGS. 19A-19D, except for the
differences that will now be described. The catheter handle 2530
shown in FIG. 25 includes the coupler 2584 and optical cable (not
shown) of the optical assembly 2540, the coupler 2584 being slid,
snapped into, molded, or otherwise mounted onto or within the
handle 2530. The components of the optical assembly 2540 are
substantially similar in construction, materials, and operation as
the components of the optical assembly described in FIGS. 20 and
23A, 23B. The light post 2588 may be included with the coupler 2584
and may be located in a recessed fitting at the rear of the handle.
The working channel port 2558 is shown to be side mounted and
distal to the activation lever 2580. In this embodiment, an ocular
(not shown) can be removably attached to the coupler 2584 for
direct viewing if a monitor is not available or connected to a
monitor if preferred.
[0134] FIG. 26 illustrates another embodiment of a catheter handle
2630 constructed in accordance with aspects of the present
invention that is suitable for use with the catheter 1910 described
above and shown in FIG. 19A. The catheter handle 2630 is
substantially similar in construction, materials, and operation as
the catheter handle 1930 described above and shown in FIGS.
19A-19D, except for the differences that will now be described. As
best shown in FIG. 26, the proximal portion 2690 of the handle 2630
has been lengthened such that the handle can be gripped at either
the distal and proximal portions to manipulate the activation lever
2680 with the thumb or other finger of the user. It is desirable
that sufficient distance exist between the working channel port
2658 and the handle activation lever 2680, so that the user can
comfortable hold the handle without blocking access to the working
channel port for device feed. The optic assembly hub 2660 is not
shown but can be positioned at the proximal handle end or exiting
another side port at the Y-connector. It will be appreciated that
the distal portion 2692 can be shortened such that the user uses
and holds the proximal end only. Further, it will be appreciated
that additional ports and hubs can be added, removed or
repositioned as desired.
[0135] In accordance with another aspect of the present invention,
it may be desirable to the user to provide a way to detect the
orientation of the optical catheter assembly once in vivo. To that
end, FIGS. 27A and 27B illustrate one suitable technique for
indicating the orientation of optical catheter assembly when routed
to a site within the patient. As best shown in FIG. 27A, an
indicator, such as a marker 2764, is placed on the optical cable
2772 of optical assembly 2740 to indicate a relative position,
e.g., left side of the optical catheter assembly, when assembled
with the catheter to aid the user in orientation and manipulation
of the system. For illustration proposes only, the selected marking
is shown in FIG. 27A at the distal end of the optic fiber cable
2772 and oriented coplanar with the deflection of the catheter
distal end as indicated by arrows A-A. In this embodiment, an
insert 2770, such as a metallic insert, is positioned at the distal
end of the catheter optical assembly lumen and may be locked into
place when the distal end of the catheter is formed. The insert
2770 is formed with the back end angle cut 2774 oriented to the
plane of deflection. The cable sleeve 2776 is also configured to
have a matching front end angle cut 2778 so that when meshed, the
marker 2764 is oriented to indicate the desired position on the
image transmitted to the handle. The meshed cuts 2774, 2778 also
perform an anti-rotation function, that is, the cable 2772 is not
allowed to rotate with respect to the catheter 2710 once meshed, as
shown in FIG. 27B. The cable 2772 in this embodiment is made
slightly longer than the catheter 2710 such that the cable deflects
slightly in the loop hub chamber (see FIG. 19C) when mated to
create a constant force against the insert 2770. It will be
appreciated that other angles, geometries, keyways, etc. may be
used to inhibit rotation of the cable with respect to the catheter
and to orient the indicator in the specified location.
[0136] In operation, when the distal end of the catheter is
deflected, the lumen length of the catheter becomes shorter due to
the radius of the deflection curve. The insert 2770 prevents the
cable 2772 from extending any further beyond the catheter distal
end. The cable length is displaced by means of the fiber deflecting
in the loop hub. As the catheter is straightened, the viscoelastic
properties of the cable 2772 allows it to relax to the center of
the loop hub, while still maintaining its position and contact with
the insert 2770 at the distal end.
[0137] FIG. 28 illustrates a distal end cap 2896 that may be
practiced with one of the catheters described above. A hole 2858
through the cap for the working channel is the same or larger than
the working lumen of the catheter body. The distal hole 2560 in the
cap for the optic fiber is size slightly smaller than the optical
cable, establishing a stop mechanism for preventing the cable from
exiting the cap yet providing a ledge for the cable to constantly
abut against. The cable in this embodiment is made slightly longer
than the catheter. The distal cap 2876 includes tapered sides 2898
to minimize the cross sectional area of the catheter distal end for
reducing trauma when advanced in-vivo.
[0138] FIG. 29 illustrates another embodiment of a catheter
assembly 2912 where a balloon 2914 is mounted on the catheter 2910
at or near the distal end 2918 with an accompanying
inflation/deflation port 2962 at the proximal end of the handle. It
will be appreciated that different types of balloons can be used
for occlusion, dilatation, anchoring, or stabilizing yet still
allow the working channel to remain patent for other uses. Other
embodiments may include side ports for injections or suction. Other
features may also be included, including an additional working
channel as well as elevators, etc. Complex curve deflection can
also be achieved as well as four or multiple way deflections.
[0139] FIG. 30 illustrates a cross section of another embodiment of
a catheter 3010. In this embodiment, it may be desired due to
economies of manufacture and in the interests of reducing the
overall outer diameter of the catheter to split the elements of the
optical cable. As best shown in FIG. 30, there is shown a
multi-lumen catheter having separate lumens 3062A and 3062B to
house the illumination and image fiber bundles 3032 and 3034,
respectively. By separating both optic cable components in this
way, a reduced catheter outer diameter may be realized.
[0140] It will be appreciated that the optical catheter system in
the various embodiments described above could be used in other
applications, such as a colonoscope, bronchoscope, gastroscope or
similar visual device. Additionally, various modifications to the
configurations, such as the number and dimension of working/optic
channels, the length of the catheter, the materials used in
construction, etc., may be made to accommodate the specific
application without departing from the spirit of the invention.
[0141] FIG. 31 illustrates one exemplary embodiment of an in-vivo
visualization system 3120 constructed in accordance with the
present invention. The visualization system 3120 includes an
endoscope 3124, such as a duodenoscope, to which a steerable
catheter assembly 3128 is operatively connected. As will be
described in more detail below, the steerable catheter assembly
3128 includes a catheter 3130 and a catheter handle 3132. The
assembly 3128 may further include a viewing device 2040, such as a
fiberscope (See FIGS. 20 and 23A-23B), or other small imaging
device that is routed through a channel of the catheter 3130 for
viewing objects at the distal end thereof. While the illustrative
embodiments described below will reference the catheter 3130 and
the handle 3132, other suitable catheters, catheter handles, and
combinations thereof may be utilized in the visualization system
3120, such as those catheters and catheter/optical handles
described above with regard to FIGS. 1-30.
[0142] In one suitable use, the endoscope 3124 is first navigated
down the esophagus of a patient and advanced through the stomach
and into the duodenum to the approximate location of the entrance
to the common bile duct (also known as the papilla). After
positioning the endoscope 3124 adjacent the common bile duct
entrance, the catheter 3130 of the catheter assembly 3128 is
advanced past the distal end of the endoscope 3124 and into the
common bile duct entrance. Alternatively, the catheter 3130 may be
routed prior to endoscope insertion. Once inside the common bile
duct, the fiberscope allows a physician to view tissue in the bile
duct, pancreatic duct and/or intrahepatics for diagnosis and/or
treatment.
[0143] As best shown in FIG. 31, one suitable embodiment of an
endoscope 3124 includes an endoscope handle 3140 and an insertion
tube 3142. The insertion tube 3142 is an elongated flexible body
that extends from the distal end of the endoscope handle 3140. In
one embodiment, the insertion tube 3142 includes an articulation
section 3144 disposed at its distal region, and a distal tip 3146.
The insertion tube 3142 is constructed of well known materials,
such as polyether block amides (e.g., Pebax.RTM.), polyurethane,
polytetrafluoroethylene (PTFE), nylon, to name a few.
[0144] As best shown in the cross sectional view of FIG. 32, the
insertion tube 3142 defines a working channel 3150 that extends the
entire length thereof and allows for the passage of various
treatment or diagnostic devices, such as guide wires, biopsy
forceps, and the steerable catheter 3130 (FIG. 31). The insertion
tube 3142 also includes one or more lumens for the purpose of
facilitating the insertion and extraction of fluids, gases, and/or
additional medical devices into and out of the body. For example,
the insertion tube 3142 may include an irrigation and/or
insufflation lumen 3152 and an optional suction lumen 3154. The
insertion tube 3142 further includes one or more lumens for the
purpose of providing endoscopic viewing procedures. For example,
the insertion tube 3142 includes one or more lumens 3156 that
extend the entire length of the catheter and allows for light and
optical fiber bundles 3158 and 3160 to be routed to the distal end
thereof. Alternatively, the insertion tube 3142 may include one or
more LED's and an image sensor, such as a CCD or CMOS, for
capturing images at the distal tip and transmitting them to the
endoscope handle 3140. Finally, the insertion tube 3142 includes at
least one pair of steering wires 3162A and 3162B, and preferably
two pairs of steering wires 3162A, 3162B and 3164A, 3164B that are
connected at the insertion tube's distal tip and terminate through
the proximal end of the insertion tube 3142. It will be appreciated
that the insertion tube 3142 may include other features not shown
but well known in the art.
[0145] Returning to FIG. 31, the proximal end of the insertion tube
3142 is functionally connected to the distal end of the endoscope
handle 3140. At the proximal end of the endoscope handle 3140,
there is provided an ocular 3166 through which a user can view the
images communicated by the optical fiber bundle 3160 (See FIG. 32),
and a light cable 3168 for connecting to an external source of
light. While the endoscope shown in FIG. 31 includes an ocular, the
endoscope may be of the electronic type, in which the ocular may be
omitted and the images obtained from the distal end of the
endoscope are transmitted to a video processor via the light cable
3168 or other suitable transmission means, and displayed by a
suitable display device, such as a LED monitor. Light from the
light source can be transmitted to the distal end of the insertion
tube 3142 via the light fiber bundle 3158. The endoscope handle
3140 also includes a steering mechanism 3170, as shown in the form
of control knobs, that are connected to the steering wires 3162A,
3162B, and 3164A, 3164B (see FIG. 32) in a conventional manner for
deflecting the distal end of the insertion tube 3142 in one or more
directions. The endoscope handle 3140 further includes a biopsy
port 3172 connected in communication with the working channel of
the insertion tube 3142 for providing access to the working channel
of the insertion tube 3142 from a position exterior the endoscope
handle 3140.
[0146] The in-vivo visualization system 3120 further includes the
steerable catheter assembly 3128 which will now be described in
more detail. As best shown in FIGS. 33 and 34, one suitable
embodiment of the catheter assembly 3128 includes a catheter handle
3132 from which the catheter 3130 extends. The catheter 3130
includes an elongated, preferably cylindrical, catheter body 3176
that extends the entire length of the catheter 3130 from the
catheter proximal end 3178 to the catheter distal end 3180. In one
embodiment, the catheter body 3176 has an outer diameter between
approximately 5 and 12 French, and preferably between approximately
7 and 10 French. The catheter body 3176 may be constructed from any
suitable material, such as Pebax.RTM. (polyether block amides),
nylon, polytetrafluoroethylene (PTFE), polyethylene, polyurethane,
fluorinated ethylene propylene (FEP), thermoplastic elastomers and
the like, or combinations thereof. The body 3176 may be formed of a
single material using known techniques in the art, such as
extrusion, or multiple materials by joining multiple extruded
sections by heat bonding, adhesive bonding, lamination or other
known techniques. According to a preferred embodiment of the
present invention, the distal portion of the catheter
(approximately 1-2 inches where the flexing occurs) is made more
flexible (i.e., less stiff) than the remainder of the catheter.
[0147] In the embodiment shown in FIG. 33, the catheter body 3176
includes a proximal section 3182 that extends the majority of the
catheter 3130, a deflection section 3184, and a distal tip section
3188. The catheter 3130 preferably varies in stiffness between the
proximal section and the distal tip section. More preferably, the
proximal section 3182 is stiffer than the deflection section 3184.
This allows the catheter to be easily advanced without compressing
and with minimal twisting while providing deflection capabilities
to the deflection section 3184 for deflecting the distal end 3180.
In one embodiment, the proximal section 3182 has a durometer value
between 35 and 85 shore D, preferable 60-80 shore D, and the
deflection section 3184 has a durometer value between 5 and 55
shore D, preferable 25-40 shore D.
[0148] FIG. 35A is a cross sectional view of one embodiment of the
catheter body 3176. The catheter body 3176 defines a working
channel 3192 that extends the length of the catheter and allows for
the passage of various treatment or diagnostic devices, such as
guide wires, stone retrieval baskets, lasers, biopsy forceps etc.
In one embodiment, the working channel 3192 preferably has a
diameter sufficient to accept up to a 4-French working device, such
as biopsy forceps. The catheter body 3176 may also include a
channel 3194 that extends the entire length of the catheter through
which a fiberscope, fiber optic cable, optical assembly or other
small diameter viewing device (e.g., 0.25 mm-1.5 mm diameter) can
be routed to the distal end of the catheter 3130. The catheter body
3176 may further include additional channels 3196, 3198 for use,
e.g., as irrigation channels or additional working channels. The
channels 3196, 3198 each extend the entire length of the catheter
and, like the working channel 3192, allow the passage of devices,
liquids and/or gases to and from the treatment area. These channels
3196, 3198 each have a diameter similar to or smaller than the main
working channel, and may be symmetrically positioned to balance the
remaining channels during extrusion. Such positioning of the
channels balances out the wall thickness and stiffness in two
transverse directions. Finally, the catheter body 3176 may include
one or more steering wire lumens 3200 that extend the entire length
of the catheter.
[0149] Referring to FIGS. 33 and 35A, the catheter 3130 further
includes one or more steering wires 3204 that cause the distal end
3180 of the catheter 3130 to deflect in one or more directions. The
steering wires 3204 are routed through a corresponding number of
steering wire lumens 3200, extend from the distal end 3180 of the
catheter 3130 to the opposing, proximal end 3182 of the catheter
3130, and terminate in a suitable manner with the steering
mechanism, as will be described in detail below. The steering wires
3204 may be attached to the distal tip section 3188 of the catheter
3130 in a conventional manner, such as adhesive bonding, heat
bonding, crimping, laser welding, resistance welding, soldering or
other known techniques, at anchor points such that movement of the
wires causes the distal end 3180 to deflect in a controllable
manner. In one embodiment, the steering wires 3204 are attached via
welding or adhesive bonding to a fluoroscopy marker band (not
shown) fixedly attached to the distal tip section. In one
embodiment, the band may be held in place via adhesive and/or an
outer sleeve, as will be described in more detail below. The
steering wires 3204 preferably have sufficient tensile strength and
modulus of elasticity that they do not deform (elongate) during
curved deflection. In one embodiment, the steering wires are made
from 304 stainless steel with an 0.008 inch diameter and have a
tensile strength of approximately 325 KPSI. The steering wires 3204
can be housed in a PTFE thin-walled extrusion (not shown) to aid in
lubricity and prevent the catheter 3130 from binding up during
deflections, if desired.
[0150] In the illustrated embodiment shown in FIG. 35A, the
catheter 3130 includes two pairs of steering wires 3204 that
controllably steer the catheter 3130 in two perpendicular planes.
In alternative embodiments, the catheter 3130 includes one pair of
steering wires 3204 that allow the user to steer the distal tip in
one plane. In one embodiment, two steering wires may be provided
and are located on opposite sides of the catheter 3130 and slide
within grooves, as opposed to steering wire lumens 3200, formed in
the elongated body 3176 or either the sheath or outer sleeve, if
included, as will be described in more detail below. In a further
embodiment, the catheter 3130 only includes one steering wire 3204
that allows the user to steer the distal tip in one direction. In
another embodiment, the steering wires may be omitted, and thus,
the catheter 3130 can be of a non-steerable type. In such an
embodiment, the catheter can be advanced over a guidewire (not
shown) pre-placed in the bile or pancreatic duct.
[0151] In one embodiment, the catheter 3130 may also include an
outer sleeve 3208 that encases the length of the elongated body
3176, as shown in cross section in FIG. 35B, or sections thereof.
The outer sleeve 3208 may comprise one of any number of polymer
jackets that are laminated, co-extruded, heat shrunk, adhesive
bonded, or otherwise attached over the catheter body 3176. Suitable
materials for the sleeve 3208 include, but are not limited to,
polyethylene, nylon, Pebax.RTM. (polyether block amides),
polyurethane, polytetrafluoroethylene (PTFE), thermoplastic
elastomers to name a few. The outer sleeve 3208 may be used to vary
the stiffness of the catheter, if desired, or to provide improved
torque transfer and/or other desirable catheter properties.
Additionally, the sleeve 3208 may be used as one convenient method
for securing a more flexible deflection section to the proximal
section, as will be described in detail below. In several
embodiments, the external surface of the sleeve 3208 may have a
hydrophilic coating or a silicon coating to ease the passage of the
device in-vivo, as was described in detail above with reference to
FIGS. 2-4.
[0152] In other embodiments, the catheter 3130 may optionally
include an inner reinforcement sheath 3210 disposed between the
elongated body 3176 and the outer sleeve 3208. The reinforcement
sheath encases the length of the elongated body 3176 or portions
thereof, as shown in FIG. 35C. The sheath 3210 may be a woven or
layered structure, such as a braided design of fine wire or
polymeric elements (0.001 inches to 0.010 inches in diameter) woven
or coiled together along the longitudinal axis of the catheter with
conventional catheter braiding techniques. This allows the catheter
to be advanced to the desired anatomical site by increasing the
column strength of the assembly while also increasing the torsional
rigidity of the catheter. Conventional coiled polymer or braid wire
may also be used for this component with coil wire dimensioning
ranging in width from 0.002 to 0.120 inches and thicknesses from
0.002 to 0.10 inches. Braided ribbon wire may also be used for the
sheath. In one embodiment, as will be described in more detail
below, the outer sleeve 3208 is coextruded, coated, or otherwise
attached once the reinforcement layer 3210 is applied, to lock the
reinforcement layer in place and secure it to the catheter body
3176, thereby forming a composite catheter.
[0153] The catheter may be constructed in many different ways to
achieve the desired result of a catheter having varying stiffness
along its length. For example, the catheter may be constructed in a
substantially similar manner to the catheters described above with
reference to FIGS. 12A-18.
[0154] FIGS. 36A-36C, and 37 illustrates one suitable embodiment of
a catheter 3630 constructed in accordance with aspects of the
present invention that may be used with the visualization system
described above. As best shown in FIG. 36A, the catheter includes a
catheter body 3676 having a proximal section 3682, a deflecting
section 3684, and a distal tip section 3686. In one embodiment, the
proximal section 3682 is constructed of a material that is stiffer
than the deflecting section 3684. The proximal section 3682 and the
deflecting section 3684 may be extrusions constructed from any
suitable material, such as polyethylene, nylon, Pebax.RTM.
(polyether block amides), polyurethane, polytetrafluoroethylene
(PTFE), and thermoplastic elastomers, to name a few. In one
preferred embodiment, the proximal section is a multi-lumen, PTFE
extrusion approximately 200 to 220 cm in length, and the deflecting
section 3684 is a multi-lumen, Pebax.RTM. extrusion approximately 2
to 10 cm in length. The deflection section 3684 may be coupled to
the proximal section 3682 via suitable adhesive or joined by other
techniques. The distal tip section 3686 may be coupled to the
distal end of the deflection section 3684 via suitable adhesive.
The distal tip section 3686 may be constructed of any suitable
material, such as stainless steel or engineering plastics,
including but not limited to polyethylene, nylon, Pebax.RTM.
(polyether block amides), polyurethane, polytetrafluoroethylene
(PTFE), and thermoplastic elastomers. The catheter body 3676 may
also include a radio opaque marker band 3692 that encircles a
portion of the distal tip section 3686.
[0155] The catheter 3630 (see FIG. 36B) also includes a
reinforcement sheath 3688 that extends from the proximal end of the
catheter to or immediately proximal of the radio opaque marker band
3692. The sheath 3688 may be a woven or layered structure, such as
a braided design of fine wire or polymeric elements (0.001 inches
to 0.010 inches in diameter) woven or coiled together along the
longitudinal axis of the catheter with conventional catheter
braiding techniques. This allows the catheter to be advanced to the
desired anatomical site by increasing the column strength of the
assembly while also increasing the torsional rigidity of the
catheter. The reinforced catheter body shown in FIG. 36B is then
encased by an outer sleeve 3690 comprising of one or more sleeve
sections 3690A, 3690B, and 3690C, having the same or different
stiffness values, as best shown in FIG. 36C, to form the catheter
3630.
[0156] Returning to FIG. 36A, the catheter also includes a
plurality of steering wires 3694 that extend through channels of
the catheter body from the proximal end of the catheter past the
deflecting section 3684. In one embodiment, the steering wires 3694
terminate at the radio opaque marker band 3694 to which the
steering wires 3694 are joined by adhesive bonding, laser welding,
resistance welding, soldering or other known techniques. In this
embodiment, the catheter body includes openings 3695 formed in the
outer surface thereof just proximal the radio opaque marker band
3694 via any suitable method, such as skiving. These openings 3695
communicate with the steering wire channels so that the steering
wires 3694 may exit the extruded catheter body and connect to the
radio opaque marker band 3694, as shown.
[0157] In some instances where the catheter body is not extruded or
otherwise constructed of PTFE or other friction reducing materials,
it may be desirable to encase the steering wires 3694 with a
laminate structure 3696 for allowing the steering wires 3694 to
move freely within the catheter body, and in particular, the
deflecting section 3684, and thus, make the mechanics of actuation
as smooth as possible. As best shown in FIG. 37, the laminate
structure 3696 is formed by outer jacket 3697 constructed of a
thermoplastic polymer, such as polyurethane, Pebax.RTM.,
thermoplastic elastomer etc. which encases an inner reinforcement
member 3698, such as a metallic braid (e.g., stainless steel braid
having, for example, a 0.0015''.times.0.006'' helically wound).
Inside the reinforcement member 3698, is a layer 3699 of a friction
reducing material, such as PTFE or FEP tubing, over which the
aforementioned layers are formed. In embodiments where the proximal
section 3682 is extruded or otherwise formed with a friction
reducing material, the laminate structure 3696 begins at the
intersection of the proximal section 3682 and the deflecting
section 3684 and extends to just proximate the radio opaque marker
band 3694, as best shown in FIG. 36A.
[0158] In accordance with one embodiment of the present invention,
the multi-lumen catheters described herein may be extruded using
known materials, such as PTFE, Nylon, Pebax.RTM., to name a few.
The catheters may be extruded using mandrels. In several
embodiments of the present invention, the mandrels may be
constructed from suitable materials, such as stainless steel,
stainless steel with PTFE coating, or a phenol plastic, such as
Cellcore.RTM.. In the embodiment shown in FIG. 35A, the multi-lumen
catheter 3130 has eight lumens that include a working channel 3192,
a fiberscope or viewing device channel 3194, and four smaller
steering wire lumens 3200 spaced 90 degrees apart. To balance out
the wall thicknesses and stiffnesses in the traverse directions
during extrusion, left and right lumens 3196, 3198 may also be
formed using separate mandrels. These lumens 3196, 3198 may be used
for air/gas irrigation and insufflation.
[0159] The catheter 3130 shown in FIG. 35B may optionally include
an outer sleeve 3208. The sleeve may be constructed of suitable
materials by coextrusion, heatshrinking processes, such as reflow,
or spray coating. The outer sleeve 3208 may provide additional
rigidity, improved torque transfer, etc. In one embodiment, the
outer sleeve may be applied for facilitating the attachment of a
flexible distal section, such as a deflection section, that has a
lower durometer value than the remaining catheter body. In such an
embodiment, one suitable material that may be used includes, but is
not limited to, Pebax.RTM. (polyether block amide). In other
embodiments, the catheter 3130 may include a reinforcement layer
3210 or sheath between the catheter body 3176 and the outer sleeve
3208, as best shown in FIG. 35C. The reinforcement may be any known
catheter reinforcement structure, such as wire coil or braid. In
such as embodiment, the outer sleeve 3208 is coextruded, coated, or
otherwise attached once the reinforcement layer 3210 is applied, to
lock the reinforcement layer in place. It will be appreciated that
the reinforcement layer 3210 may extend the entire length of the
catheter or portions thereof. In one embodiment, the reinforcement
layer 3210 extends over the deflection section. It will be
appreciated that if the body is extruded from PTFE, its outer
surface should be etched or otherwise prepared for appropriate
bonding with the outer layer.
[0160] In accordance with another embodiment, the catheter may be
built up using a catheter core 3820, an optional reinforcement
layer 3824, and an outer sheath or jacket 3826, as best shown in
FIGS. 38A-38C. The catheter core 3820 is an open-lumen core that is
extruded from suitable materials, such as nylon, PTFE, Pebax.RTM.,
etc., with the use of mandrels. In this embodiment, the mandrels
(not shown) are placed and configured to produced a plurality of
open-lumens 3892, 3894, 3896, 3898, and 3899 when extruded. The
mandrels may be constructed from metal, Cellcore.RTM., or PTFE.
Once the open-lumen core has been extruded, the mandrels are kept
in place and the core is either coextruded to add the outer sleeve
3826, as shown in FIG. 38B, or braided and coextruded to add a
reinforcement layer 3824 and an outer sleeve 3826, as shown best in
FIG. 38C. As was discussed above, the outer sleeve 3826 may
function to lock the braid in place and/or to facilitate attachment
of a distal section, such as a deflection section, having, for
example, a lower stiffness value, if desired.
[0161] The mandrels (not shown) can then be removed after
coextrusion. In one embodiment, the mandrels are constructed of a
phenol plastic, such as Cellcore.RTM.. To remove these mandrels,
the mandrels are pulled from one or both ends. Due to the "necking
down" effect inherent to the Cellcore.RTM. material, the cross
sectional areas of the mandrels decrease when pulled in tension,
thereby allowing the mandrels to be removed from the built-up
catheter. In one embodiment, this property of Cellcore.RTM. may be
used to the manufacture's advantage by using such a material for
the steering wire lumen mandrels. However, instead of completely
removing the mandrels from the steering wire lumens, tension forces
may be applied to the steering wire mandrels, and the mandrels may
be drawn to a decreased diameter that will be sufficient to
function as the steering wires. Thus, to be used as steering wires,
the drawn mandrels are then connected to the distal end of the
catheter in a conventional manner. While the latter embodiment was
described as being coextruded to form the outer sheath, the outer
sheath may be formed on the catheter core by a heat shrink process
or spraycoating.
[0162] It will be appreciated that not all of the lumens in the
latter embodiments need to be formed as open-lumens. Thus, as best
shown in FIG. 39A-39C, only the steering wire lumens 3999 are
formed as open-lumens. This will create over sized lumens for the
steering wires and provided the largest possible lumen diameters
for the lumens 3992, 3994, 3996, and 3998.
[0163] As was described above, in several embodiments of the
catheter, it is desirable for the deflection section to be
configured to deflect more easily than the proximal section. In one
embodiment, the deflection section has a durometer value less than
the proximal section. In other embodiments, the flexibility may be
varied gradually (e.g., increasingly) throughout the length of a
catheter tube from its proximal end to its distal end. In other
embodiments, the deflection section may be an articulating joint.
For example, the deflection section may include a plurality of
segments that allow the distal section to deflect in one or more
directions. For examples of articulation joints that may be
practiced with the present invention, please see co-pending U.S.
patent application Ser. Nos. 10/406,149, 10/811,781, and
10/956,007, the disclosures of which are hereby incorporated by
reference. Other methods that my be used were described above with
reference to FIGS. 16-18.
[0164] Returning to FIGS. 33 and 34, the catheter 3130 is
functionally connected to the catheter handle 3132. The handle 3132
includes a handle housing 3220 to which a steering mechanism 3224,
one or more ports 3226, 3228, 3230, and an endoscope attachment
device 3234 is operatively connected. In one embodiment, the handle
housing 3220 is formed by two housing halves 3220A and 3220B joined
by appropriate removable fasteners, such as screws, or non
removable fasteners, such as riveting, snaps, heat bonding or
adhesive bonding. In the embodiment shown, the proximal end of the
catheter 3130 is routed through a strain relief fitting 3238
secured at the distal end of the handle housing 3220 and terminates
at a Y connector 3242, as best shown in FIGS. 34 and 45. The Y
connector 3242 may be secured to the handle housing 3220 via any
suitable means, such as adhesive bonding. Similarly, the proximal
end of the catheter 3130 is securely coupled to the Y connector
3242 via suitable means known in the art, such as adhesive bonding.
The Y connector 3242 includes first and second branch fittings 3244
and 3246 that define respective passageways 3248 and 3250 for
communicating with the catheter working channel and the catheter
imaging device channel, respectively, through openings 3251 and
3252 located on the outer surface of the catheter, as best shown in
FIG. 45.
[0165] In embodiments of the present invention, the openings 3251
and 3252 may be formed by skiving the outer surface of the
catheter. This process may be done manually using known mechanical
techniques, or may be accomplished by laser micro-machining that
removes a localized area of material from the outer surface of the
catheter to expose one or more catheter channels. When assembled,
the proximal ends of the catheter channels are plugged by adhesive
or the proximal end of the catheter is capped to prohibit access to
the channels.
[0166] As was described above, the handle housing 3220 includes one
or more ports 3226, 3228, 3230 for providing access the respective
channels of the catheter 3130. In the embodiment shown, the ports
include, but are not limited to, a working channel port 3226, an
imaging device port 3228, and an irrigation/suction port 3230. The
ports may be defined by any suitable structure. For example, the
working channel port 3226 and the imaging device port 3228 may be
defined by fittings 3254 and 3256, respectively, that may be bonded
or otherwise secured to the handle housing 3220 when assembled. In
one embodiment, the housing halves may define cooperating structure
that securely locks the fittings 3254 and 3256 in place when
assembled. With regard to the irrigation/suction port 3230, a luer
style fitting 3258 is preferably used for defining the port 3230.
The fitting 3258 defines a passageway 3260 for fluidly connecting
the port 3230 with the appropriate catheter channels, as best shown
in FIG. 41. The fitting 3258 works in conjunction with a barrel
connector 3264 that ensconces the catheter 3130. The barrel
connector 3264 defines a cavity 3266 that surrounds the perimeter
of the catheter 3130 and is fluidly connected to the appropriate
catheter channels (irrigation channels) via inlets 3270. As such,
the port 3230 is connected in fluid communication with the
irrigation channel via passageway 3260 and cavity 3266. In one
embodiment, the inlets 3270 are formed by skiving the outer surface
of the catheter. This process may be done manually using known
mechanical techniques, or may be accomplished by laser
micro-machining that removes a localized area of material from the
outer surface of the catheter to expose one or more catheter
channels. The working channel port 3226 and the imaging device port
3228 are connected in communication with the branch fittings 3254
and 3256 of the Y connector, respectively, via appropriate tubing
3272, and best shown in FIG. 34.
[0167] The catheter handle 3132 also includes a steering mechanism
3224. The steering mechanism 3224 of the catheter handle 3132
controls deflection of the distal end 3180 of the catheter 3130.
The steering mechanism 3224 may be any known or future developed
mechanism that is capable of deflecting the distal end of the
catheter by selectively pulling the steering wires. In the
embodiment shown in FIGS. 33 and 34, the steering mechanism 3224
includes two rotatable knobs for effecting 4-way steering of the
catheter distal end in the up/down direction and in the right/left
direction. This mechanism 3224 includes an outer knob 3280 to
control up/down steering and an inner knob 3284 to control
right/left steering. Alternatively, the inner knob 3284 may
function to control right/left steering and an outer knob 3280 may
function to control up/down steering. The knobs are connected to
the distal end of the catheter 3130 via the steering wires 3204,
respectively, that extend through the catheter 3130. While a
manually actuated steering mechanism for effecting 4-way steering
of the distal is shown, it will be appreciated that a manually
actuated steering mechanism that effects 2-way steering may be
practiced with and is therefore considered to be within the scope
of the present invention.
[0168] Referring now to FIG. 42, there is shown one embodiment of
the steering mechanism 3224 that may be practiced with the present
invention. The steering mechanism 3224 includes inner and outer
pulleys 3288 and 3290, and control knobs 3280 and 3284. The inner
pulley 3288 for left and right bending control is mounted via an
inner bore 3294 for rotation on a shaft 3296 integrally formed or
otherwise positioned to extend into the interior of the handle
housing 3220 in a fixed manner from the housing half 3220A. The
inner pulley 3288 is integrally formed or keyed for rotation with
one end of an inner rotary shaft 3300. The opposite end of the
inner rotary shaft 3300 extends outside the handle housing 3220 to
which the control knob 3280 is attached for co-rotation. In one
embodiment, the end 3304 of the inner rotary shaft 3300 is
configured to be keyed with a cooperatingly configured control knob
opening. The control knob 3280 may then be retained thereon via a
threaded fastener. The proximal end of one pair of steering wires
3204 are connected to opposite sides of the inner pulley 3288 in a
conventional manner.
[0169] The outer pulley 3290 for up and down bending control is
rotatably fitted over the inner rotary shaft 3300 for independent
rotation with respect to the inner pulley 3288. The outer pulley
3290 is integrally formed or keyed for rotation with one end of an
outer rotary shaft 3310. The outer rotary shaft 3310 is
concentrically arranged in a rotational manner over the inner
rotary shaft 3300. The opposite end of the outer rotary shaft 3310
extends outside the handle housing 3220 to which the control knob
3284 is attached for co-rotation. The rotary shafts 3300, 3310 are
further supported for rotation within the housing 3220 by a boss
3316 integrally formed or otherwise positioned to extend inwardly
into the handle housing 3220 from the housing half 3220B. It will
be appreciated that other structure may be provided that rotatably
supports the pulleys 3288, 3290 and shafts 3300, 3310 within the
handle housing 3220. When assembled, the proximal ends of the
second pair of steering wires 3204 are fixedly connected in a
conventional manner to the outer pulley 3290, respectively.
[0170] In one embodiment, a thrust plate 3320 is positioned between
the inner and outer pulleys 3288, 3290 for isolating rotary motion
therebetween. The thrust plate 3320 is restricted from rotation
when assembled within the housing 3220.
[0171] The steering mechanism 3224 may further includes a lock
mechanism 3340 that functions to lock the catheter 3130 in a
desired deflection position during use. The lock mechanism 3340
includes a lever 3344 that is actuatable between a locked position
and an unlocked position. In the embodiment shown in FIG. 40,
detents 3346 are provided, and may be molded into the exterior
housing half 3220B to index the movement between the locked and
unlocked positions. A small protuberance (not shown) may be
included to signal the user that the lever 3344 has changed
positions.
[0172] Referring now to FIGS. 42, 43A, and 43B, the lock mechanism
3340 further includes a lever member 3350 and a pulley member 3354
that are housed within the handle housing 3220 when assembled. The
lever member 3350 includes a throughbore 3358 that is size and
configured for receiving the outer rotary shaft 3310 in a
rotationally supporting manner. The lever member 3350 includes a
boss section 3362 that is sized and configured to be rotationally
supported by the inwardly extending boss 3316 when assembled. The
boss section 3362 is configured at one end 3364 to be keyed for
rotation with one end of the lock lever 3344. The lever member 3350
further includes a flange 3366 integrally formed at the other side
of the boss section 3362. The end face 3368 of the flange 3366
defines a cam profile that annularly extends around the perimeter
of the flange 3366. In the embodiment shown, the cam profile is
formed by varying the thickness of the flange. The pulley member
3354 includes a boss section 3370 that is sized and configured for
receiving the lever member 3350 therein. The pulley member 3354
includes an inwardly extending flange 3374 that defines a cam
profile on the lever member facing surface 3378 of the flange 3374.
Similar to the lever member 3350, the cam profile of the pulley
member 3354 is formed by varying the thickness of the flanges as it
annularly extends. The inwardly extending flange 3374 further
defines a throughbore 3380 that is sized and configured for
receiving the outer rotary shaft 3310 in a rotationally supporting
manner. When assembled, the pulley member 33254 is restricted from
rotating with respect to the housing 3220 but allowed to linearly
translate, as will be described in more detail below.
[0173] When assembled, the lever member 3350 is inserted within the
pulley member 3354, the cam profiles mate, and the lever 3344 is
keyed for rotation to the lever member 3350. The cam profiles on
the lever member 3350 and the pulley member 3354 are specifically
configured to transmit a rotary motion of the lever 3344 into
translational movement of the pulley member 3354. Thus, when the
lever member 3350 rotates by movement of the lever 3344 from the
unlocked position to the locked position, the pulley member 3354
moves away from the lever member 3350 in a linear manner by
coaction of the cam profiles. Therefore, the lever member 3350 acts
like a cam, and the pulley member 3354 acts like a follower to
convert rotary motion of the lever 3344 into linear motion of the
pulley member. The linear movement of the pulley member 3354 causes
the inner pulley 3288 to frictionally engage the housing 3220 and
the thrust plate 3320 while the outer pulley 3290 frictionally
engages the thrust plate on one side and the pulley member of the
other. The friction present between the engaged surfaces prohibits
rotation of the inner and outer pulleys 3288 and 3290, and thus,
locks the distal end of the catheter in a deflected position.
[0174] To change the deflection of the distal end of the catheter
from one position to another, the lock lever 3344 is moved from the
locked position to the unlocked position. This, in turn, rotates
the lever member 3350 with respect to the pulley member 3354. Due
to the configuration of the cam profiles of the lever and pulley
members, the pulley member 3354 is capable of moving toward the
lever member 3350. This alleviates the friction between the
engagement surfaces and allows the inner and outer pulleys 3288 and
3290 to rotates by turning the control knobs 3284 and 3280.
[0175] In accordance with aspects of the present invention, the
catheter assembly 3128 can be mounted directly to the endoscope
handle 3140 so that a single user can manipulate both the endoscope
3124 and the catheter assembly 3128 using two hands. In the
embodiment shown, the catheter handle 3132 is attached to the
endoscope 3124 via the endoscope attachment device, such as the
strap 3234. The strap 3234 can be wrapped around the endoscope
handle 3140, as best shown in FIG. 31. The strap 3234 includes a
number of notches 3366 into which the head of a housing projection
3368 is selectively inserted to couple the catheter handle to the
endoscope, as best shown in FIG. 44. The strap 3234 allows the
catheter handle 3132 to rotate around the shaft of the endoscope
3124, if desired. The strap 3234 is positioned such that when used
to attach the handle 3132 to the endoscope 3130, the longitudinal
axes of the both handles are substantially aligned, as shown best
in FIG. 31. Additionally, the strap orientation and the location of
the ports on the catheter handle 3132 allow for manipulation of
diagnostic or treatment devices and viewing devices through the
catheter without interfering with control and use of the endoscope.
As a result of directly connecting the catheter assembly 3128 to
the endoscope 3124, as shown in FIG. 31, the catheter 3130 creates
a loop, known as a service loop, prior to entrance into the biopsy
port 3172. In one embodiment, the catheter may include a proximally
located stop sleeve or collar (not shown), which limits the minimum
diameter of the service loop and the extension of the catheter 3130
beyond the distal end of the conventional endoscope. Alternatively,
a mark or indicia may be placed on the catheter 3130 and used to
prevent over insertion of the catheter 3130.
[0176] In embodiments of the present invention that form a service
loop by directly connected the catheter handle 3132 to the
endoscope 3124, the catheter 3130 is preferably constructed to be
suitably longer than conventional catheters to compensate for the
service loop. In several of these embodiments, the catheter handle
3132 is preferable mounted below the biopsy port 3172 of the
endoscope 3124 and the catheter 3130 is preferably looped upward
and into the biopsy port 3172. In this configuration, the catheter
3130 is accessible and can be gripped by the user just above the
biopsy port for catheter insertion, withdrawal, and/or
rotation.
[0177] While the embodiment above shows a handle connected below
the biopsy port and longitudinally oriented with respect to the
catheter, other configurations are possible. For example, the
handle can be attached to the endoscope so that the longitudinal
axis of the catheter handle is substantially transverse to the
longitudinal axis of the endoscope handle. Additionally, the
catheter handle may be mounted proximally or distally of the biopsy
port or may be mounted directly on the biopsy port so that the
longitudinal axis of the catheter is coaxial with the biopsy
port.
[0178] As was discussed briefly above, a small diameter viewing
device, such as a fiberscope or other vision device, may be
slidably routed through one channel (e.g., imaging device channel)
of the catheter 3130 (FIG. 33) to the distal end thereof. The
viewing device permits the user of the catheter assembly to view
objects at or near the distal end or tip of the catheter. For a
detailed description of one viewing device that may be utilized by
the visualization system, please see the optical assembly described
above with regard to FIGS. 20 and 23A-23B. For other examples of
imaging devices that may be practiced with embodiments of the
present invention, please see the description of the fiber optic
cable in co-pending U.S. application Ser. No. 10/914,411, filed
Aug. 9, 2004 to which priority as been claimed, and the guidewire
scope described in U.S. Published Patent Application Number
2004/0034311 A1, the disclosures of which are hereby incorporated
by reference.
[0179] The imaging device 3370 may have a stop collar or sleeve
(not shown) to limit movement of the cable 3372 through the imaging
device channel of the endoscope and limit the length by which the
cable 3372 can extend beyond the distal tip of the catheter 3130.
The inner surface of the imaging channel of the catheter may have
color markings or other calibration means to indicate to the user
when inserting the cable 3372 that the end of the catheter is
approaching or has been reached.
[0180] One suitable method of operation of the in-vivo
visualization system 3120 will now be described in detail with
reference to the aforementioned FIGURES. The insertion tube 3142 of
the endoscope 3124 is first navigated down the esophagus of a
patient under endoscope visualization. The insertion tube 3142 of
the endoscope 3124 is advanced through the stomach and into the
duodenum at the bottom of the stomach. The biliary tree comprises
the cystic duct from the gall bladder, the hepatic duct from the
liver and the pancreatic duct from the pancreas. Each of these
ducts joins into the common bile duct. The common bile duct
intersects with the duodenum a slight distance below the stomach.
The papilla controls the size of the opening at the intersection
between the bile duct and duodenum.
[0181] The papilla must be crossed in order to reach the common
bile duct to perform a biliary procedure. The insertion tube 3142
of the endoscope 3124 is navigated under direct visualization so
that the exit port of the working channel 3150 is directly across
from the papilla or so that the port is slightly below the papilla.
After positioning the distal end of the insertion tube 3142 in the
proper position, the catheter 3130 with the imaging device 3370 is
advanced through the working channel 3150 the endoscope 3124 such
that the distal end of the catheter 3130 emerges from the endoscope
and cannulates the papilla. The endoscope 3124 provides viewing of
the catheter 3130 as it emerges from the endoscope 3124 and is
advanced to enter the papilla. After cannulating the papilla, the
catheter 3130 may be advanced into the common bile duct. Once
advanced into the common bile duct, the fiber optic cable 3372 of
the viewing device 3370 located within the catheter 3130 allows a
physician to view tissue in the bile duct for diagnosis and/or
treatment.
[0182] Alternatively, once the insertion tube 3142 of the endoscope
3124 is in place next to the papilla, a conventional guidewire and
sphinctertome may be advanced together through the endoscope and
through the papilla to enter the common bile duct and pancreatic
duct. It may be necessary for the physician to use the
sphinctertome to enlarge the papilla. The sphinctertome may then be
removed from the patient while leaving the conventional guidewire
in place. The catheter 3130 and the fiber optic cable 3372 of the
viewing device 3370 may then be advanced together over the
conventional guidewire through the papilla and into the common bile
duct. Once inside the common bile duct, the fiber optic cable 3372
of the viewing device 3370 allows a physician to view tissue in the
bile duct for diagnosis and/or treatment.
[0183] It will be appreciated that the selection of materials and
use of insertable and removable optics in the catheter allow for
the catheter to be constructed as a single use device. Once the
procedure is performed, the optics can be removed and sterilized
for reuse while the catheter may be removed from the endoscope and
discarded.
[0184] While the steerable catheter assembly 3128 has been
described above for use with an endoscope, it will be appreciated
that the catheter assembly may be used with other devices, or may
be used as a stand-alone device or in conjunction with the viewing
device 3370.
[0185] FIGS. 46A-46B illustrates the distal end of an alternative
embodiment of a catheter 4630 formed in accordance with aspects of
the present invention. In this embodiment, the catheter 4630 has a
multi-lumen design with one or more (shown as three) steering wire
lumens 4640 around its perimeter. Steering wires (not shown) extend
from the proximal end of the catheter to the distal region of the
catheter and terminate in an anchored connection at or near the
distal end thereof. Deflection of the distal end of the catheter
may be effected by the steering wires in a manner well known in the
art. The catheter 4630 includes other lumens, for example, a guide
wire lumen 4660, a working channel lumen 4662, and a fiberscope or
other viewing device lumen 4664. As shown, the guide wire lumen
4660 is offset from the longitudinal axis of the catheter.
[0186] In use, the tip of the catheter is advanced beyond the end
of the endoscope and is steered in the direction of the papilla.
The guide wire is then advanced through the papilla and the
catheter is advanced to cannulate the papilla. Once in the biliary
tree, and with visualization provided via the fiberscope or other
viewing device, the guide wire is advanced again and steered to the
target site. The catheter is once more advanced over the guide wire
and positioned for use of the accessory instruments at the therapy
site while simultaneously viewing such site with the
fiberscope.
[0187] In an alternative embodiment, instead of extruding the
catheter body, a catheter 4730 may be constructed with an outer
sheath 4758 encasing a bundle 4770 of smaller diameter tubes, as
best shown in FIG. 47. Each tube of the bundle of tubes may be
formed using any known technique, such as extrusion. Each tube
extends the length of the catheter and may be used for a specific
function, such as steering wire lumens, device working channel,
optic channel, fluid or air infusion channel, or section channel,
etc. Each tube is preferably separately constructed with materials
specifically selected to maximize performance, lubricity,
flexibility, and/or other desirable characteristics. When
assembled, one or more steering wires 4774 are routed through a
corresponding number of steering tubes 4776 of the catheter. The
steering wires 4774 may be connected to the distal end of the
catheter via adhesive, heat bonding, crimping, or other known
techniques. In one embodiment, the steering wires may be attached
to a radio opaque marker band 4780 for use in fluoroscopy.
[0188] Alternatively, as best shown in FIG. 48, a catheter 4830 may
be formed from a steering sheath 4854, such as a steering guide
catheter of appropriate dimensions, by filling the central
longitudinal lumen 4856 with a bundle of tubes. The steering sheath
4854 typically includes an outer sleeve or jacket 4858 with an
internal sleeve or liner 4862. The steering wires 4874 typically
run along the inner surface of the catheter to the distal end and
are located within channels 4877 defined by the internal sleeve or
liner 4862. The liner preferably has a low coefficient of friction
to facilitate the passage of wires, and may be formed from a
polymer containing PTFE or PTFE impregnated thermoplastic
elastomers, or may be constructed of thermoplastic materials, such
as polyamides, polyurethane, polyethylene, and block copolymers
thereof.
[0189] The principles, preferred embodiments, and modes of
operation of the present invention have been described in the
foregoing description. However, the invention which is intended to
be protected is not to be construed as limited to the particular
embodiments disclosed. Further, the embodiments described herein
are to be regarded as illustrative rather than restrictive.
Variations and changes may be made by others, and equivalents
employed, without departing from the spirit of the present
invention. Accordingly, it is expressly intended that all such
variations, changes, and equivalents which fall within the spirit
and scope of the present invention.
* * * * *