U.S. patent application number 10/406149 was filed with the patent office on 2004-10-07 for endoscopic imaging system.
This patent application is currently assigned to SCIMED Life Systems, Inc.. Invention is credited to Banik, Michael S., Boulais, Dennis R., Chin, Albert C.C., Couvillon, Lucien Alfred JR., Hunter, Ian W..
Application Number | 20040199052 10/406149 |
Document ID | / |
Family ID | 33097264 |
Filed Date | 2004-10-07 |
United States Patent
Application |
20040199052 |
Kind Code |
A1 |
Banik, Michael S. ; et
al. |
October 7, 2004 |
Endoscopic imaging system
Abstract
An endoscopic imaging system includes a reusable control cabinet
having a number of actuators that control the orientation of a
lightweight endoscope that is connectable thereto. The endoscope is
used with a single patient and is then disposed. The endoscope
includes an illumination mechanism, an image sensor and an elongate
shaft having one or more lumens located therein. A polymeric
articulation joint at the distal end of the endoscope allows the
distal end to be oriented by the control cabinet. The endoscope is
coated with a hydrophilic coating that reduces its coefficient of
friction and because it is lightweight, requires less force to
advance it to a desired location within a patient.
Inventors: |
Banik, Michael S.; (Bolton,
MA) ; Boulais, Dennis R.; (Danielson, CT) ;
Couvillon, Lucien Alfred JR.; (Concord, MA) ; Chin,
Albert C.C.; (Newton, MA) ; Hunter, Ian W.;
(Lincoln, MA) |
Correspondence
Address: |
CHRISTENSEN, O'CONNOR, JOHNSON, KINDNESS, PLLC
1420 FIFTH AVENUE
SUITE 2800
SEATTLE
WA
98101-2347
US
|
Assignee: |
SCIMED Life Systems, Inc.
|
Family ID: |
33097264 |
Appl. No.: |
10/406149 |
Filed: |
April 1, 2003 |
Current U.S.
Class: |
600/142 |
Current CPC
Class: |
A61B 2017/00327
20130101; A61B 2017/00309 20130101; A61B 1/008 20130101; A61B 1/015
20130101; A61B 2017/00314 20130101; A61B 1/00042 20220201; A61B
1/05 20130101; A61B 1/0008 20130101; A61B 1/0051 20130101; A61B
1/0055 20130101; A61B 1/0057 20130101; A61B 1/0052 20130101; A61B
1/31 20130101; A61B 1/00096 20130101; A61B 1/04 20130101; A61B
2017/0042 20130101; A61B 1/0016 20130101; A61B 1/0676 20130101;
A61B 1/00071 20130101; A61B 1/00147 20130101; A61B 1/0638 20130101;
A61B 1/0684 20130101 |
Class at
Publication: |
600/142 |
International
Class: |
A61B 001/00 |
Claims
The embodiments of the invention in which an exclusive property or
privilege is claimed are defined as follows:
1. An imaging endoscope, comprising: a shaft having a proximal end
and a distal end; an illumination port at the distal end of the
shaft for illuminating tissue; an imaging port at the distal end of
the shaft that includes an imaging sensor to produce an image of
the tissue; a plastically deformable articulation joint disposed at
the distal end of the shaft comprising a molded or extruded
polymeric cylinder having a central lumen and a number of control
cable lumens disposed about the circumference of the cylinder; a
number of live hinges formed in the cylinder; and a number of
control cables that are selectively activated to bend the
articulation joint in a desired direction.
2. The imaging endoscope of claim 1, further comprising a working
channel lumen in the shaft through which a medical device may be
passed.
3. The imaging endoscope of claim 1 wherein each live hinge
comprises two or more diametrically opposed angled cutouts in the
polymeric cylinder that are joined by flexible webs.
4. The imaging endoscope of claim 3, wherein the control cables are
aligned with the flexible webs of the live hinges.
5. The imaging endoscope of claim 3, wherein the control cables are
offset from the flexible webs of the live hinges.
6. The imaging endoscope of claim 3, wherein adjacent live hinges
along the length of the articulation joint are rotated with respect
to each other.
7. The imaging endoscope of claim 1, wherein the shaft is coated
with a lubricious material.
8. The imaging endoscope of claim 1, wherein the shaft includes an
insufflation/irrigation lumen.
9. The imaging endoscope of claim 1, wherein at least a portion of
the shaft includes a spiral wrap.
10. The imaging endoscope of claim 9, wherein the spiral wrap is
approximately 0.060 inches thick and has a pitch of about {fraction
(3/16)} inches.
11. The imaging endoscope of claim 1, wherein the articulation
joint comprises an extruded cylinder made of two or more materials
having different durometers.
12. The imaging endoscope of claim 11, wherein the control cable
lumens are within a material having a higher durometer.
13. The imaging endoscope of claim 1, wherein the shaft is covered
by a sleeve that includes wound wrap.
14. The imaging endoscope of claim 16, wherein the wrap has a
number of threads and a pitch selected to adjust the torque
characteristics of the shaft.
15. The imaging endoscope of claim 16, wherein the threads of the
wound wrap are made of wire.
16. The imaging endoscope of claim 16, wherein the wound wrap has
two or more threads that are braided.
17. The imaging endoscope of claim 1, wherein the articulation
joint is longitudinally retractable by tensioning all the control
cables.
18. The imaging endoscope of claim 1, further comprising a sleeve
that selectively exposes the distal end of the endoscope.
19. An imaging endoscope, comprising: a shaft having a proximal end
and a distal end; an illumination port at the distal end of the
shaft for illuminating tissue; an imaging port at the distal end of
the shaft that includes an imaging sensor to produce an image of
the tissue; a plastically deformable articulation joint wherein the
articulation joint includes a number of stacked annular disks each
having a number of holes through which the control cables pass and
camming surfaces that engage an adjacent annular disk in the
articulation joint.
20. The imaging endoscope of claim 19, wherein the camming surfaces
of adjacent annular disks are rotated with respect to each
other.
21. An imaging endoscopic system, comprising: a control cabinet
including a number of actuators that operate to control the
orientation of an endoscope; an imaging board for producing images
received from an image sensor in an endoscope; one or more valves
to control the delivery of an irrigation fluid and insufflation
air/gas to one or more lumens in an endoscope; a handheld
controller including a number of controls that can be activated by
a physician to supply commands to the control cabinet; and a single
use endoscope that is connectable to the control cabinet, the
endoscope including: a shaft with a proximal end and a distal end;
an illumination mechanism for illuminating tissue; an image sensor
at the distal end of the endoscope for producing images of tissue;
an articulation joint that permits the distal end of the endoscope
to move; and a number of control cables that are selectively
tensioned by the actuators to orient the distal tip of the
endoscope.
22. The imaging endoscope system of claim 21, wherein the proximal
end of the endoscope is connectable to the control cabinet.
23. The imaging endoscopic system of claim 21, wherein the
endoscope is connected to the control cabinet through the handheld
controller.
24. The imaging endoscopic system of claim 21, wherein the handheld
controller is connected to the control cabinet through a wired
link.
25. The imaging endoscopic system of claim 21 wherein the handheld
controller is connected to the motion control cabinet through a
wireless link.
26. A system for obtaining images of a patient's internal body
cavity, comprising: a reusable control cabinet including: means for
controlling the movement of a distal end of an endoscope; means for
controlling the delivery of an irrigation fluid and/or an
insufflation air/gas to lumen(s) of the endoscope; means for
producing images of tissue received from signals produced by an
image sensor at the distal end of an endoscope; an input mechanism
for supplying signals to control the operation of the control
cabinet; and a disposable endoscope that is connectable to the
control cabinet that obtains images of tissue in the body cavity
and is controllable by the control cabinet.
27. The system of claim 26, wherein the input mechanism comprises a
handheld controller connected to the control cabinet with a wired
link.
28. The system of claim 26, wherein the input mechanism comprises a
handheld controller connected to the control cabinet with a
wireless link.
29. An endoscope, comprising: a shaft having a proximal end, a
distal end and a central lumen extending therethrough; an
illumination port at the distal end of the shaft; an imaging port
including an image sensor at the distal end of the shaft; an
articulation joint at or adjacent the distal end of the shaft
comprising a molded or extruded polymeric cylinder having a number
of hinge mechanisms that can be opened and closed to bend the
distal end of the shaft; and a number of control cables that are
selectively tensioned to close one or more of the hinge mechanisms
of the articulation joint.
30. The endoscope of claim 29, wherein the shaft is coated with a
hydrophilic coating.
31. The endoscope of claim 29, wherein the shaft includes a spiral
wrap therein.
32. The endoscope of claim 29, wherein the illumination port
includes a number of light emitting diodes.
33. The endoscope of claim 29, wherein the illumination port
includes a number of optical fibers that direct illumination light
received from an external source.
34. The endoscope of claim 29 wherein the polymeric articulation
joint is formed of two or more materials each having a different
durometer.
35. The endoscope of claim 34, wherein the control cables pass
through lumens in the articulation joint that are within a material
having a higher durometer.
36. The endoscope of claim 29, wherein the hinge mechanisms are
equally spaced along the length of the articulation joint.
37. The endoscope of claim 29, wherein the hinge mechanisms are not
equally spaced along the length of the articulation joint.
38. An imaging endoscope, comprising: a shaft having a proximal
end, a distal end and a working channel lumen therein; a number of
control cables that are connectable to a number of motion
controllers to control the orientation of the distal tip; an
articulation joint comprising a braided stent that is moved by the
control cables to orient the distal tip of the endoscope; one or
more light emitting diodes at the distal tip to produce
illumination light; and an image sensor at the distal end of the
endoscope to produce images of tissue.
39. The imaging endoscope of claims 40, further comprising: means
for dissipating heat from the light emitting diodes and image
sensor.
40. The imaging endoscope of claim 38, further comprising a lumen
into which a liquid or gas is delivered and an orifice in the lumen
adjacent the light emitting diode and image sensor to direct the
air or gas over the light emitting diodes and image sensor to
dissipate heat.
41. An endoscope for viewing internal body cavities of a patient,
comprising: a shaft having a central lumen and a braid embedded
within a wall of the shaft; a plastically deformable articulation
joint at or adjacent a distal end of the endoscope, the
articulation joint including a number of live hinges and lumens
through which control cables are passed; a number of control cables
within the lumens of the articulation joint; wherein the distal end
of the endoscope may be turned in a desired direction by
selectively tightening control cables and the distal tip of the
endoscope can be retracted by tightening all the control cables
simultaneously.
42. The endoscope of claim 45, wherein the control cables are made
of metal.
43. The endoscope of claim 45, wherein the control cables are made
of PET.
44. The endoscope of claim 41, wherein the control cables are
routed within spiral wrapped lumens within the sleeve.
45. An endoscope for viewing internal body cavities of a patient,
comprising: a shaft having a lumen therein; an articulation joint
at or near the distal end of the shaft for selectively orienting
the distal end of the shaft; an imaging system positioned at or
adjacent the distal end of the shaft including a light source and
an image sensor for capturing images of the patient's body cavity;
and a retractable sleeve that selectively uncovers the distal end
of the shaft for use with a patient and recovers the distal end of
the shaft after a patient examination procedure.
46. The endoscope of claim 45, wherein the retractable sleeve is
connected to a gripper on the shaft that is used to rotate the
shaft.
47. The endoscope of claim 46, wherein the shaft is coated with a
hydrophilic coating and the gripper includes a sponge that can be
wetted to activate the hydrophilic coating.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to medical devices in general
and therapeutic and diagnostic endoscopes in particular.
BACKGROUND OF THE INVENTION
[0002] As an aid to the early detection of disease, it has become
well established that there are major public health benefits from
regular endoscopic examinations of internal structures such as the
esophagus, lungs, colon, uterus, and other organ systems. A
conventional imaging endoscope used for such procedures comprises a
flexible tube with a fiber optic light guide that directs
illuminating light from an external light source through a lens at
the distal end of the endoscope which focuses the illumination on
the tissue to be examined. An objective lens and fiber optic
imaging light guide communicating with a camera at the proximal end
of the scope, or an imaging camera chip at the distal tip, transmit
an image to the examiner. In addition, most endoscopes include one
or more working channels through which medical devices such as
biopsy forceps, snares, fulguration probes, and other tools may be
passed.
[0003] Navigation of the endoscope through complex and tortuous
paths is critical to success of the examination with minimum pain,
side effects, risk or sedation to the patient. To this end, modern
endoscopes include means for deflecting the distal tip of the scope
to follow the pathway of the structure under examination, with
minimum deflection or friction force upon the surrounding tissue.
Control cables similar to puppet strings are carried within the
endoscope body and connect a flexible portion of the distal end to
a set of control knobs at the proximal endoscope handle. By
manipulating the control knobs, the examiner is usually able to
steer the endoscope during insertion and direct it to the region of
interest, in spite of the limitations of such traditional control
systems, which are clumsy, non-intuitive, and friction-limited.
Common operator complaints about traditional endoscopes include
their limited flexibility, limited column strength, and limited
operator control of stiffness along the scope length.
[0004] Conventional endoscopes are expensive medical devices
costing in the range of $25,000 for an endoscope, and much more for
the associated operator console. Because of the expense, these
endoscopes are built to withstand repeated disinfections and use
upon many patients. Conventional endoscopes are generally built of
sturdy materials, which decreases the flexibility of the scope and
thus can decrease patient comfort. Furthermore, conventional
endoscopes are complex and fragile instruments which can frequently
need expensive repair as a result of damage during use or during a
disinfection procedure. To overcome these and other problems, there
is a need for a low cost imaging endoscope that can be used for a
single procedure and thrown away. The scope should have better
navigation and tracking, a superior interface with the operator,
improved access by reduced frictional forces upon the lumenal
tissue, increased patient comfort, and greater clinical
productivity and patient throughput than those that are currently
available.
SUMMARY OF THE INVENTION
[0005] To address these and other problems in the prior art, the
present invention is an endoscopic video imaging system. The system
includes a motion control cabinet that includes a number of
actuators that control the orientation of an endoscope and an
imaging system to produce images of tissue collected by an image
sensor at the distal end of the endoscope. A single use endoscope
is connectable with the control cabinet and used to examine a
patient. After the examination procedure, the endoscope is
disconnected and disposed of.
[0006] The endoscope of the present invention includes a flexible
elongate tube or shaft and an illumination source that directs
light onto a tissue sample. An image sensor and objective lens at
or adjacent the distal end of the endoscope captures reflected
light to produce an image of the illuminated tissue. Images
produced by the sensor are transmitted to a display device to be
viewed by an examiner. In one embodiment, the illumination source
comprises one or more light emitting diodes (LEDs) and the image
sensor comprises a CMOS solid state image sensor.
[0007] The endoscope of the present invention also includes a
steering mechanism such as a number of tensile control cables,
which allow the distal end of the endoscope to be deflected in a
desired direction. In one embodiment of the invention, a proximal
end of the tensile control cables communicates with actuators
within the control cabinet. A freestanding joystick controller
generates electrical control signals which the control cabinet uses
to compute signals to drive the actuators that orient the distal
end of the endoscope in the direction desired by the examiner. In
another embodiment of the invention, the distal end of the
endoscope is automatically steered, or provided to the examiner,
based on analysis of images from the image sensor.
[0008] In one embodiment of the invention, the endoscope includes a
polymeric articulation joint adjacent its distal end that aids in
bending the distal end of the scope in a desired direction. The
articulation joint is constructed as a number of live hinges
integrated into a unified structure of the required overall
properties and dimensions. Tension of the control cables causes the
live hinges of the articulation joint to deflect, thereby bending
the distal tip of the endoscope. In one embodiment of the
invention, the articulation joint exerts a restoring force such
that upon release of a tensioning force, the distal end of the
scope will straighten.
[0009] In an alternative embodiment, the articulation joint
comprises a number of stacked discs that rotate with respect to one
another. Control cables pass through the discs and pull adjacent
discs together to turn the distal end of the endoscope.
[0010] In another embodiment of the invention, the endoscope has a
variation in stiffness along its length that allows the distal end
to be relatively flexible while the more proximal regions of the
scope have increased column strength and torque fidelity so that a
physician can twist and advance the endoscope with greater ease and
accuracy and with fewer false advances ("loops"). Variation in
stiffness along the length can be provided by varying the durometer
of materials that comprise a shaft of the endoscope.
Operator-controlled, variable stiffness can be provided by control
cables that can be tightened or loosened to adjust the stiffness of
the shaft. In yet another embodiment, the spacing between the live
hinges of the articulation joint is selected to provide a variation
in stiffness along the length of the articulation joint.
[0011] In yet another embodiment of the invention, the endoscope is
covered with a retractable sleeve that uncovers the distal end of
the scope during use and extends over the distal end after the
scope is removed from a patient.
[0012] In another embodiment of the invention, the scope is coated
with a hydrophilic coating to reduce its coefficient of
friction.
[0013] In another embodiment of the invention, the scope is
retractable in a longitudinal direction. The distal end of the
scope is extendable using a spring, pull wires, bellows or the like
to allow a physician to move the distal tip without having to alter
the position of the shaft of the endoscope.
[0014] In yet another embodiment of the invention, the endoscope
includes a heat dissipating mechanism for removing heat produced by
the illumination source and image sensor.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The foregoing aspects and many of the attendant advantages
of this invention will become more readily appreciated as the same
become better understood by reference to the following detailed
description, when taken in conjunction with the accompanying
drawings, wherein:
[0016] FIGS. 1A and 1B illustrate two possible embodiments of an
endoscopic video imaging system in accordance with the present
invention;
[0017] FIG. 2 illustrates further detail of an endoscope used in
the imaging system shown in FIG. 1A;
[0018] FIG. 3A is a block diagram of a motion control cabinet that
interfaces with an imaging endoscope in accordance with one
embodiment of the present invention;
[0019] FIG. 3B is a block diagram of a motion control cabinet that
interfaces with an imaging endoscope in accordance with another
embodiment of the present invention;
[0020] FIGS. 4A-4D illustrate one mechanism for connecting the
vision endoscope to a motion control cabinet;
[0021] FIG. 5 is a detailed view of one embodiment of a handheld
controller for controlling an imaging endoscope;
[0022] FIG. 6 illustrates one embodiment of a distal tip of an
imaging endoscope in accordance with the present invention;
[0023] FIG. 7 illustrates one mechanism for terminating a number of
control cables in a distal tip of an imaging endoscope;
[0024] FIG. 8 illustrates an imaging endoscope having control
cables routed through lumens in the walls of an endoscope
shaft;
[0025] FIGS. 9A and 9B illustrate a transition guide that routes
control cables from a central lumen of an endoscope shaft to lumens
in an articulation joint;
[0026] FIGS. 10A and 10B illustrate the construction of a shaft
portion of an endoscope in accordance with one embodiment of the
present invention;
[0027] FIG. 1I illustrates one mechanism for providing a shaft
having a varying stiffness along its length;
[0028] FIGS. 12A and 12B illustrate an extrusion used to make an
articulation joint in accordance with one embodiment of the present
invention;
[0029] FIG. 13 illustrates an articulation joint in accordance with
one embodiment of the present invention;
[0030] FIGS. 14 and 15 illustrate an extrusion having areas of a
different durometer that is used to form an articulation joint in
accordance with another embodiment of the present invention;
[0031] FIGS. 16A and 16B illustrate another embodiment of an
articulation joint including a number of ball and socket
sections;
[0032] FIGS. 17A-17D illustrate various possible configurations of
ball and socket sections used to construct an articulation
joint;
[0033] FIGS. 18A-18B illustrate an articulation joint formed of a
number of stacked discs in accordance with another embodiment of
the present invention;
[0034] FIGS. 19A-19B illustrate a disc used to form an articulation
joint in accordance with another embodiment of the present
invention;
[0035] FIGS. 20A-20B illustrate a disc used to form an articulation
joint in accordance with another embodiment of the present
invention;
[0036] FIGS. 21A-21B illustrate a non-circular segment used to form
an articulation joint in accordance with another embodiment of the
present invention;
[0037] FIG. 22 illustrates an endoscope having a braided member as
an articulation joint in accordance with another embodiment of the
present invention;
[0038] FIG. 23 illustrates one possible technique for securing the
ends of a control wire to a braided articulation joint;
[0039] FIG. 24 illustrates a shaft having one or more memory
reducing wraps in accordance with another embodiment of the present
invention;
[0040] FIG. 25 illustrates a shaft including longitudinal stripes
of a high durometer material in accordance with another embodiment
of the present invention;
[0041] FIGS. 26-29 illustrate alternative embodiments of a gripping
mechanism that rotates an imaging endoscope shaft in accordance
with the present invention;
[0042] FIGS. 30A and 30B illustrate a retractable sleeve used with
another embodiment of the present invention;
[0043] FIG. 31 illustrates one embodiment of a heat dissipating
distal tip of an endoscope in accordance with the present
invention; and
[0044] FIGS. 32 and 33 illustrate alternative embodiments of a heat
dissipating distal tip in accordance with the present
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0045] As indicated above, the present invention is an endoscopic
video imaging system that allows a physician to view internal body
cavities of a patient as well as to insert surgical instruments
into the patient's body. An imaging endoscope used with the present
invention is sufficiently inexpensive to manufacture such that the
endoscope can be considered a disposable item.
[0046] As shown in FIG. 1A, an endoscopic video imaging system 10
according to one embodiment of the present invention includes an
imaging endoscope 20, a motion control cabinet 50 and a handheld
controller 80. The imaging endoscope 20 has a distal tip 22 that is
advanced into a patient's body cavity and a proximal end 24 that is
connected to the motion control cabinet 50. As will be explained in
further detail below, the motion control cabinet 50 includes a
number of actuators that control a steering mechanism within the
endoscope in order to change the orientation of the distal tip 22.
A physician or their assistant uses the handheld controller 80 to
input control signals that move the distal tip 22 of the imaging
endoscope 20. In addition, the motion control cabinet 50 may
include connections to sources of air/gas and a flushing liquid
such as water for clearing the imaging endoscope. The motion
control cabinet 50 also includes imaging electronics to create
and/or transfer images received from an image sensor to a video
display for viewing by a physician or technician.
[0047] In the embodiment shown, the imaging endoscope 20 also
includes a breakout box 26 that is positioned approximately midway
along the length of the endoscope. The breakout box 26 provides an
attachment point for a vacuum bottle 40 that collects liquids from
a lumen within the imaging endoscope. The vacuum bottle 40 is
controlled by a vacuum valve 28 that is positioned on the breakout
box 26. Alternatively, the valve can be positioned within the
motion control cabinet 50 and controlled from the handheld
controller 80.
[0048] If desired, the handheld controller 80 can be secured to the
breakout box 26 such that the two units can be moved as one if
desired. Upon completion of a patient examination procedure, the
imaging endoscope 20 is disconnected from the motion control
cabinet 50 and disposed of. A new imaging endoscope 20 is then
connected to the motion control cabinet 50 for the next examination
procedure to be performed.
[0049] The embodiment shown in FIG. 1A is a "parallel"
configuration whereby the endoscope 20 and handheld controller 80
are separately plugged into different connectors of the motion
control cabinet 50. This parallel configuration allows one operator
to handle the endoscope while another operator can handle the
handheld controller 80. Alternatively, the handheld controller 80
may be secured to the endoscope 20 such that a single operator can
control both. FIG. 1B illustrates a "serial" configuration of the
invention. Here, the imaging endoscope 20 is connected to the
motion control cabinet 50 through the handheld controller 80.
[0050] FIG. 2 shows further detail of one embodiment of the imaging
endoscope 20. At the proximal end of the endoscope is a low torque
shaft 24 and a connector 34 that connects the endoscope 20 to the
motion control cabinet 50. Distal to the breakout box 26 is a
higher torque shaft. At the distal end of the endoscope 20 is the
distal tip 22 that includes a light illumination port, an image
sensor, an entrance to a working lumen and a flushing lumen (not
shown). Proximal to the distal tip 22 is an articulation joint 30
that provides sufficient flexibility to the distal section of the
shaft such that the distal tip 22 can be directed over an angle of
180 degrees by the steering mechanism.
[0051] As discussed above, the endoscope 20 in accordance with one
embodiment of the invention, has a higher torque shaft at the
distal section of the endoscope and a lower torque shaft at its
proximal end. The breakout box 26 positioned along the length of
the endoscope shaft can be used as a handle or gripper to impart
rotation of the distal end of the endoscope during a medical
examination procedure. The higher torque portion of the shaft
transfers rotational motion that is imparted at a location proximal
to the distal tip in order to guide the distal tip of the imaging
catheter. The low torque shaft portion of the imaging catheter does
not transfer torque as well and can twist when rotational motion is
applied.
[0052] In use, the physician can insert a medical device such as a
biopsy forceps, snare, etc., into a connector 32 found on the
breakout box 26 that leads to a working channel lumen in the
endoscope. In alternate embodiments, the entrance to the working
channel lumen may be positioned further towards the proximal end of
the endoscope.
[0053] FIG. 3A is a block diagram of the major components included
within one embodiment of the motion control cabinet 50. The motion
control cabinet is preferably positioned on a cart that is wheeled
near a patient prior to an examination procedure. The motion
control cabinet is connected to a source of electrical power,
either A.C. mains or a battery, as well as to a source of
insufflation gas and irrigation liquid. Inside the motion control
cabinet 50 is a controller interface 52 that is connected to the
handheld controller 80 and receives control signals therefrom. To
change the orientation of the distal tip of the imaging endoscope,
the control signals are received from a directional switch in the
handheld controller 80. The control signals are supplied to a servo
motor controller 54 that in turn controls a number of actuators,
such as servo motors 56a, 56b, 56c, 56d. Each of the servo motors
56a-56d is connected to one or more control cables within the
imaging endoscope. Motion of the servo motors 56a-56d pulls or
releases the control cables in order to change the orientation of
the distal tip 22 of the imaging endoscope 20. Although the
embodiment shown in FIG. 3A shows four servo motors and control
cables, it will be appreciated that fewer or more servo motors and
corresponding control cables could be used to move the distal tip.
For example, some imaging endoscopes may use three control cables
and three associated servo motors.
[0054] Also included in the motion control cabinet 50 is a power
source 58 that provides electrical power to a light source such as
a number of light emitting diodes (LEDs) at the distal end 22 of
the imaging endoscope. Alternatively, if the imaging catheter
utilizes an external light source, then the motion control cabinet
can include a high intensity light source such as a laser or Xenon
white light source that supplies light to a fiber optic
illumination guide within the imaging endoscope 20 in order to
illuminate an internal body organ. The power source 58 may be
controlled by control signals received from the handheld controller
80 when the user desires to activate the light source.
[0055] An imaging electronics board 60 captures images received
from an image sensor (not shown) at the distal end of the imaging
endoscope. The imaging electronics board 60 can enhance the images
received or can provide video effects such as zoom, color changes,
highlighting, etc., prior to display of the images on a video
display (not shown). Images of the tissue may also be analyzed by
the imaging electronics board 60 to produce control signals that
are supplied to the servo motor controller 54 in order to
automatically steer the distal tip of the endoscope as will be
discussed in further detail below. Images produced by the imaging
electronics board 60 may also be printed on a digital printer,
saved to a computer readable media such as a floppy disk, CD, DVD,
etc., or a video tape for later retrieval and analysis by a
physician.
[0056] Finally, the motion control cabinet 50 includes valves 70
that control the delivery of insufflation air/gas to insufflate a
patient's body cavity and an irrigation liquid to flush out a body
cavity and/or clean the imaging light source and image sensor at
the distal end of the endoscope. The insufflation air/gas and
irrigation liquid are connected to the imaging catheter via a
connector 38 that connects to an irrigation/insufflation lumen of
the imaging endoscope 20. In one embodiment of the invention, the
irrigation and insufflation lumen are the same lumen in the imaging
catheter. However, it will be appreciated that separate irrigation
and insufflation lumens could be provided if desired and if space
in the endoscope permits.
[0057] FIG. 3B illustrates another embodiment of a motion control
cabinet 50A that is similar to the cabinet shown in FIG. 3A. The
motion control cabinet 50A includes a vacuum valve 71 that controls
vacuum delivered to a vacuum collection bottle 40. A vacuum line 73
connects to a vacuum lumen within the imaging endoscope 20. The
vacuum valve 71 is controlled from the handheld controller 80.
[0058] FIGS. 4A-4D illustrate one mechanism for securing the
proximal end of the imaging endoscope to the control cabinet 50
prior to performing an endoscopic examination. The control cabinet
50 includes a connector 34A having a number of shafts 57 that are
driven by the servo motors 56 shown in FIGS. 3A and 3B. Each shaft
57 is shaped to be received in a corresponding spool on which the
control cables are wound. Also included in the connector 34A are
connections to the insufflation and irrigation valves 70 and vacuum
valve 71 to provide air, water and vacuum to the endoscope.
[0059] FIGS. 4A and 4B illustrate one possible connector 34 found
at the proximal end of the endoscope 20 for securing the endoscope
to the motion control cabinet 50. The connector 34 includes a
number of thumbscrews 77 or other quick release mechanisms that
allow the connector 34 to be easily secured to the connector 34A on
the motion control cabinet. As shown in FIG. 4C, the connector 34A
includes a number of spools 79 about which the control cables are
wound. Each spool is preferably threaded or grooved to prevent the
control cables from binding on the spool during use. A cover may
surround a portion of the spool to keep the control cables against
the spool and to aid in supporting the spool within the connector
34. In one embodiment of the invention, the spools are prevented
from rotating when the connector is not engaged with the motion
control cabinet 50 by brakes 81 having pins that fit within
corresponding slots in the spool. Once the connector 34 is mounted
to the motion control cabinet 50, the brakes 81 are disengaged from
the spool such that the spool can be moved by the servo motors.
Electrical connections for the light source and image sensor as
well as connections to the air and water valves can be found on the
sides of the connector or on the rear face of the connector 34 to
engage the valves, as shown in FIG. 4A.
[0060] FIG. 4D illustrates a cross-sectional view of a shaft 57
fitted within a spool 79. The shaft 57 is supported by a cylinder
59 having a spring 61 therein such that the shaft 57 is free to
move within the cylinder 59. The cylinder 59 is directly coupled to
the servo motors within the motion control cabinet. The spring 61
allows the shaft 57 to float such that the shaft can more easily
align and engage the mating surface of the spool 79.
[0061] Upon insertion of the shaft 57 into the spool 79, the brake
81 is released, thereby allowing the spool 79 to be moved by
rotation of the cylinder 59. In some instances, the brake 81 may be
omitted, thereby allowing the spools 79 to freely rotate when the
connector 34 is not engaged with the motion control cabinet 50.
[0062] FIG. 5 illustrates various controls located on the handheld
controller 80 in accordance with one embodiment of the invention.
The handheld controller 80 includes a controller body 82 that, in
the parallel embodiment of the invention, is coupled to the motion
control cabinet 50 by an electrical cord 84, a wireless radio
frequency channel, an infrared or other optical link. If the
connection is made with an electrical cord, a strain relief 86 is
positioned at the junction of the electrical cord 84 and the body
82 of the controller to limit the bending of the electrical wires
within the electrical cord 84. In the serial embodiment of the
invention, the connection of the handheld controller 80 to the
motion control cabinet 50 is made with a conductor that includes
both the wires to transmit signals to the motion controllers and
imaging systems, as well as a lumens to carry the insufflation
air/gas and irrigation liquid. In addition, the control cables of
the endoscope engage cables connected to the actuators in the
motion control cabinet through the handheld controller 80.
[0063] Positioned in an ergonomic arrangement on the handheld
controller 80 are a number of electrical switches. An articulation
joystick 88 or other multi-positional device can be moved in a
number of positions to allow the physician to orient the distal tip
of the imaging endoscope in a desired direction. In order to guide
the imaging endoscope manually, the physician moves the joystick 88
while watching an image on a video monitor or by viewing the
position of the distal tip with another medial imaging technique
such as fluoroscopy. As the distal tip of the endoscope is steered
by moving the joystick 88 in the desired direction, the physician
can push, pull and/or twist the endoscope to guide the distal tip
in the desired direction.
[0064] A camera button 90 is provided to capture an image of an
internal body cavity or organ in which the imaging endoscope 20 is
placed. The images collected may be still images or video images.
The images may be adjusted for contrast or otherwise enhanced prior
to display or storage on a recordable media.
[0065] An irrigation button 92 activates an irrigation source to
supply a liquid such as water through an irrigation lumen of the
imaging endoscope. The liquid serves to clean an image sensor and
the light source at the distal end of the endoscope as well as an
area of the body cavity. An insufflation button 94 is provided to
activate the insufflation source within the motion control cabinet
50 to supply air/gas through a lumen of the catheter. The supply of
the insufflation gas expands portions of the body cavity around the
distal tip of the endoscope so that the physician can more easily
advance the endoscope or better see the tissue in front of the
endoscope.
[0066] In one embodiment of the invention, the handle 82 also
includes a thumb screw 96 for securing the handheld controller 80
to the breakout box 26 as indicated above. A corresponding set of
threads on a breakout box 26 receive the thumb screw 96 in order to
join the two parts together. One or more additional buttons 98 may
also be provided to activate additional functions such as recording
or printing images, adjusting light intensity, activating a vacuum
control valve, etc., if desired.
[0067] The endoscope of the present invention may also be steered
automatically. Images received by the imaging electronics 60 are
analyzed by a programmed processor to determine a desired direction
or orientation of the distal tip of the endoscope. In the case of a
colonoscopy, where the endoscope is advanced to the cecum, the
processor controls the delivery of insufflation air/gas to inflate
the colon, the processor then analyzes the image of the colon for a
dark spot that generally marks the direction in which the scope is
to be advanced. The processor then supplies control instructions to
the servo controller 54 such that the distal tip is oriented in the
direction of the dark spot located.
[0068] In other modes, a processor in the motion control cabinet
causes the distal tip of the endoscope to move in a predefined
pattern. For example, as the scope is being withdrawn, the distal
tip may be caused to move in a search pattern such that all areas
of a body cavity are scanned for the presence of disease. By using
the automatic control of the distal tip, a physician only has to
advance or retract the scope to perform an examination.
[0069] As will be described in further detail below, the imaging
endoscope 20 generally comprises a hollow shaft having one or more
lumens formed of polyethylene tubes which terminate at the distal
tip 22. As shown in FIG. 6, one embodiment of a distal tip 110
comprises a cylinder having a distal section 112 and a proximal
section 114. The proximal section 114 has a smaller diameter than
the diameter of the distal section 112 in order to form a stepped
shoulder region. The diameter of the shoulder is selected that
shaft walls of the endoscope can seat on the shoulder region to
form a smooth outer surface with the distal section 112. The distal
face of the distal tip 110 includes a number of ports, including a
camera port 116, one or more illumination ports 118, an access port
or working channel lumen 120, and a directional flush port 122.
[0070] Fitted within the camera port 116 is an image sensor (not
shown) that preferably comprises a CMOS imaging sensor or other
solid state device and one or more glass or polymeric lenses that
produce electronic signals representative of an image of the tissue
in front of the camera port 116. The image sensor is preferably a
low light sensitive, low noise video VGA, CMOS, color imager or
higher resolution sensor such as SVGA, SXGA, or XGA. The video
output of the sensor may be in any conventional format including
PAL, NTSC or high definition video format.
[0071] The illumination port 118 houses one or more lenses and one
or more light emitting diodes (LEDs) (not shown). The LEDs may be
high intensity white light sources or may comprise colored light
sources such as red, green and blue LEDs. With colored LEDs, images
in different spectral bands may be obtained due to illumination
with any-one or more individual colors. White light images may be
obtained by the simultaneous or sequential illumination of the
colored LEDs and combining individual color images. As an
alternative to LEDs, the light source may be external to the
endoscope and the illumination light delivered to the illumination
port with a fiber optic bundle.
[0072] The access port 120 is the termination point of the working
channel or lumen of the endoscope 20. In the embodiment described
above, the proximal end of the working channel terminates at the
breakout box 26 as shown in FIG. 2. However, the working channel
could terminate nearer the proximal end of the imaging
catheter.
[0073] The directional flush port 122 includes a cap 124 that
directs liquid supplied through an irrigation and insufflation
lumen across the front face of the distal tip 110 in the direction
of the camera port 116 and/or the illumination port 118. The cap
124 thereby serves to clean the camera port 116 and the
illumination port 118 for a better view of the internal body cavity
in which the imaging catheter is placed. In addition, the flushing
liquid cleans an area of tissue surrounding the distal end of the
endoscope.
[0074] FIG. 7 shows further detail of one embodiment of a distal
tip 110 of the imaging endoscope. In this embodiment, the tip
section 110 includes a number of counter bored holes 126 that are
positioned around the circumference of the distal tip 110. The
counter bored holes 126 receive swaged or flanged ends of the
control cables that orient the distal tip. Tension on the control
cables pull the distal tip 110 in the direction of the tensioning
force.
[0075] FIG. 8 is a lengthwise, cross-sectional view of an imaging
endoscope 20 in accordance with one embodiment of the present
invention. The distal tip 110 is adhesively secured, welded or
otherwise bonded within a center lumen at the distal end of the
articulation joint 30. Secured to the proximal end of the
articulation joint 30 is a distal end of a shaft 128. As discussed
above, the shaft 128 is preferably stiffer or better able to
transmit torque towards the distal end of the endoscope than at the
proximal end of the endoscope.
[0076] The control cables 130 that move the distal tip of the
endoscope are preferably made of a non-stretching material such as
stainless steel or a highly oriented polyethylene-theralate (PET)
string. The control cables may be routed within a center lumen of
the shaft 128 or, as shown in FIG. 8, may be routed through lumens
formed within the walls of the shaft. The control cables 130 extend
through guides within the walls of articulation joint 30 and
terminate either at the distal end of the articulation joint 30 or
in the distal tip section 110.
[0077] If the control cables are routed through the center lumen of
the shaft 128, the cables are preferably carried in stainless steel
or plastic spiral wrapped lumens to prevent binding and a
transition guide 140 such as that as shown in FIGS. 9A and 9B may
be used to guide the control cables into the proximal end of the
articulation joint. The transition guide 140 has a proximal end 142
that is secured within a lumen of the distal end of the shaft. A
central body portion 144 of the transition guide 140 has a diameter
equal to the outer diameter of the imaging endoscope. In addition,
the body portion 144 includes a number of diagonal lumens 148 that
extend from a center lumen of the proximal end 142 to an outer
surface of a stepped distal end 146 of the transition guide. The
distal end 146 is secured within a proximal end of the articulation
joint 30. Control cables in the diagonally extending lumens 148 are
therefore guided to the outer edge of the catheter where they
extend through the guides or control cable lumens of the
articulation joint 30.
[0078] FIGS. 10A, 10B illustrate one embodiment of a shaft that
comprises the imaging endoscope 20. The shaft 160 has a cover 162
that may include a wire or other braid 164 embedded therein. The
braid 164, if present, allows the torque characteristics of the
shaft to be adjusted. The cover 162 may be formed by placing a
sleeve over a mandrel. The braid 164 is placed over the sleeve and
the mandrel is dipped into or sprayed with a coating material.
Preferably the sleeve and coating material are made of polyurethane
or other biocompatible materials such as polyethylene,
polypropylene or polyvinyl alcohol. In addition, the interior
lumen(s) and exterior of the shaft can be coated with a extrudable,
hydrophilic, lubricious coating such as the HYDROPASS.TM.
hydrophilic coating available from Boston Scientific, of Natick,
Mass., and described in U.S. Pat. Nos. 5,702,754 and 6,048,620
which are herein incorporated by reference.
[0079] A plastic spiral wrap 166 such as spiral wire wrap available
from Panduit Inc. is inserted into a lumen of the cover 162. The
spiral wrap 166 prevents the shaft 160 from crushing as it is bent
around a patient's anatomy.
[0080] In one embodiment of the shaft 160, the spiral wrap has a
thickness of 0.060 inches and a pitch of {fraction (3/16)} inch.
However, it will be appreciated that other thicknesses of spiral
wrap with a different pitch could be used to provide the desired
column strength and bend modulus as well as to prevent kinking.
[0081] FIG. 11 shows one method of altering the torque fidelity of
the distal and proximal portions of the shaft. The shaft 160 has a
flexible section 170 that is proximal to the break out box and a
stiffer section 172 that is distal to the break out box. The
portion of the scope that is distal to the break out box has an
increasing flexibility toward the distal tip and conversely a
higher torque fidelity and column strength proximally. To increase
the torque fidelity characteristics of the distal section 172 of
the shaft, a braid 164 in that section includes two or more wires
that are wound in opposite directions. In one embodiment, the wire
braid has a pitch of 14-16 pik. However, the number of wires and
their spacing can be adjusted as needed in order to tailor the
torque fidelity of the shaft.
[0082] The proximal end 170 of the shaft 160 has a single spiral of
wire 176 that is preferably wound in the same direction as the
plastic spiral wrap 166 in the center lumen of the shaft 160.
Again, the torque fidelity of the proximal end of the shaft 170 can
be adjusted by adjusting the pitch and/or direction of the wire 176
and its flexibility.
[0083] As will be appreciated, the single wire spiral 176 provides
some torque fidelity but does have the same torque fidelity as the
dual wire braid in the distal section of the shaft. The single wire
spiral 176 may be omitted from the proximal portion of the shaft if
even less torque fidelity is desired.
[0084] In order to facilitate steering the distal tip of imaging
endoscope, the endoscope includes an articulation joint that allows
the distal tip to be turned back on itself, i.e., over an arc of
180 degrees, by the control cables. As shown FIG. 12A, 12B[,?] an
articulation joint 200 is formed from a cylinder of a plastically
deformable material having a central lumen 202, and a number of
control wire lumens 204 located in the walls of the articulation
joint. If desired, the space between the control wire lumens in the
cylinder wall may be thinner such that the control wire lumens form
bosses that extend into the central lumen of the cylinder. The
control cable lumens 204 are preferably oriented at 120.degree.
apart if three control cables are used or 90.degree. apart if four
control cables are used.
[0085] To facilitate bending of the articulation joint, the
cylinder includes a number of live hinges 220 formed along its
length. As can be seen in FIG. 13, each live hinge 220 comprises a
pair of opposing V-shaped cuts 230 on either side of the cylinder
and are separated by a flexible web 232 that forms the bendable
portion of the hinge. In the embodiment designed for four control
cables, each live hinge is oriented at 90 degrees with respect to
an adjacent hinge.
[0086] Upon retraction of a control cable, those live hinges having
webs 232 that are in line with the retracting control cable do not
bend. Those live hinges having webs that are not in line with the
control cable will be closed, thereby bending the articulation
joint in the direction of the control cable under tension.
[0087] Another advantage of the articulation joint shown in FIG. 13
is that the distal end of the scope can be retracted by pulling all
the control cables simultaneously. This allows the physician to
maneuver the distal tip in the body without having to move the
remaining length of the endoscope. This may be useful when
performing surgical procedures such as obtaining a biopsy or
snaring polyps.
[0088] The articulation joint can be formed by extruding a cylinder
with the central and control cable lumens in place and cutting the
cylinder tube with a knife, laser, water jet, or other material
removal mechanism to form the live hinges. Alternatively, the
articulation joint can be molded with the live hinge joints in
place. As will be appreciated, the angles of the V-shaped cuts that
form the hinges may be uniform or may vary along the length of the
articulation joint. Similarly, the distance between adjacent live
hinges may be uniform or may vary in order to tailor the bending
and torque fidelity characteristics of the articulation joint. In
one embodiment of the invention, each live hinge has a closing
angle of 30.degree. so that six hinges are required to provide
180.degree. of movement. The distal end of the articulation joint
200 may be counter-bored to receive the distal tip section 110 of
the endoscope, as discussed above. Similarly, the proximal end of
the articulation joint 200 is adapted to receive the distal end of
the shaft of the endoscope. In the embodiment shown in FIG. 13, the
control cable lumens 204 are aligned with the widest spacing of the
live hinges and with the web portion of each hinge. However, it may
be desirable to offset the control cable lumens 204 with respect to
the hinges in order to lessen potential binding of the control
cables in the hinge. As indicated above, the articulation joint
should be made of a biocompatible material that will bend but will
not collapse. Suitable materials include polyurethane,
polyethylene, polypropylene, or other biocompatible polymers.
[0089] To prevent wear by the control cables as they are pulled by
the actuation mechanism in the motion control cabinet, it may be
desirable to produce the articulation joint from a material having
areas of different durometers. As shown in FIGS. 14 and 15, a
cylinder formed from an extruded tube 240 has alternating bands of
a high durometer material 242 and a lower durometer material 244
around its circumference. The lumens 246 used to route the control
cables are formed in the high durometer material to resist abrasion
as the control cables are tensioned and released. In addition, the
high durometer material also reduces friction between the control
cables and the surrounding lumen. FIG. 15 illustrates an
articulation joint where the control cable lumens are offset with
respect to the orientation of the web portions 248 of the live
hinges so that the control cables do not pass through the web
portion of the hinge.
[0090] FIGS. 16A, 16B illustrate an alternative embodiment of an
articulation joint. In this embodiment, the joint comprises a
series of ball and socket connectors that are linked together. As
shown in FIG. 16A, each connector includes a socket section 290 and
a ball section 292. The ball section 292 fits in a socket section
290 of an adjacent connector. A lumen 294 extends axially through
the ball section 292 to allow for passage of the wires that connect
to the light source and the image sensor and tubes that carry
irrigation fluids and insufflation gases. The ball and socket
sections are preferably molded of a biocompatible polymer.
[0091] Each socket section can be formed with a fully formed ball
section such as ball section 300 shown in FIG. 17A. Alternatively,
a partial ball section such as ball section 304 can be formed on a
socket section 306 as shown in FIG. 17B. To provide room for the
control cables to move, the ball section can include slot 308 as
shown in FIGS. 17A, 17B that cuts through the middle and sides of
the ball section. Alternatively, a number of smaller slots 310 can
be positioned around the circumference of the ball section as shown
in FIGS. 17C and 17D. The slots allow the control cables to be
shortened under tension. A number of holes 312 at the interface of
the ball section and socket section allows passage of the control
cables from the socket section into the ball section as shown in
FIG. 17D.
[0092] In another embodiment of an articulation joint, the joint is
made of a series of stacked discs that are positioned adjacent one
another and move with respect to each other. As shown in FIG. 18A,
a disc 350 comprises an annular ring 352 having a pair of rearward
facing rocker surfaces or cams 354 and a pair of forward facing
rocker surfaces or cams 356. The cams 354 are positioned
180.degree. apart on the rear surface of the annular ring 352,
while the forward facing cams 356 are positioned 180 degrees apart
on the forward face of the annular ring 352. In the embodiment
shown, the forward cams 356 are oriented at 90.degree. with respect
to the rear cams 354. Opposite each cam on the other side of the
annular ring is a flat land section so that the cams of an adjacent
disc may engage with and rock on the flat section. Holes 360 are
drilled through the annular ring and through the cams for passage
of the control cables. Upon tension of the control cables, the
discs will rock on the surface of the cams 354, 356 thereby bending
the articulation joint in the desired direction.
[0093] FIG. 18B shows an articulation joint made up of a series of
stacked discs 350a, 350b, 350c . . . engaged with one another to
form an articulation joint. A number of control cables 370a, 370b,
370c, 370d, pass through the discs and are used to pull the discs
on the cam surfaces to move the joint in the desired direction.
[0094] FIGS. 19A and 19B show an alternative embodiment of the
articulation joint shown in FIGS. 18A and 18B. In this embodiment,
an articulation joint comprises a series of stacked discs 380, each
comprising an annular ring having a pair of concave pockets 382 on
its rear surface and a pair of correspondingly shaped convex cams
384 on its front surface. The concave pockets 382 are oriented at
90.degree. with respect to the convex cams 384 so that adjacent
discs may be stacked such that the cams of a disc fit within the
pockets of the adjacent disc. The corresponding shaped cams 384 and
pockets 382 help prevent the discs from rotating with respect to
one another. Holes or lumens 386 are formed through the annular
ring 380 for passage of a number of control cables 390a, 390b,
390c, 390d, as shown in FIG. 19B. The holes or lumens 386 may be
positioned at the center of the cams and pockets. However, the
holes for the control cables may be offset from the position of the
cams and pockets, if desired. Preferably discs 380 are molded from
a biocompatible polymer having a relatively slick surface, such as
polyurethane, polypropylene, or polyethylene, that reduces friction
between adjacent cams and pockets.
[0095] FIGS. 20A and 20B show yet another alternative embodiment of
an articulation joint. In this embodiment, the articulation joint
is formed of a stack of discs, each of which comprises an annular
ring. The annular ring has cams having an arcuate slot 392 molded
therein that allows a control cable to move more freely in the cam
as the disc is moved relative to an adjacent disc. As best shown in
FIG. 20B, the slot 392 tapers from a widest point 394 at the outer
edge of the cam to a narrow point 396 where the slot forms a
cylindrical hole 398 that extends to the opposite edge of the
annular ring 380. A control wire 390b is free to bend within the
widened portion of the arcuate slot 392 as an adjacent disc is
rotated.
[0096] Although the discs of the articulation joints shown in FIGS.
18-20 are generally circular in shape, it will be appreciated that
other shapes could be used. FIGS. 21A and 21B show an articulation
joint formed from a number of sections having a generally square
outer shape. As shown in FIG. 21A, a section 400 is a square band
having a pair of pins 402 that extend outwardly on opposite sides
of the rear surface of the square section. On the opposite sides of
the front surface are a pair of opposing circular recesses 404 that
are sized to receive the round pins 402 of an adjacent section. The
embodiment shown, the control cables are routed through holes or
lumens in corner blocks 406 that are found in each corner of the
square section 400. FIG. 21B shows two adjacent square sections
400a, 400b secured together. As can be seen, the section 400b can
rotate up or down on its pins with respect to the adjacent section
400a. Although circular and square articulation sections have been
shown, it will be appreciated that other segment shapes such as
triangular or pentagonal, etc., could also be used to form an
articulation joint.
[0097] In some environments, a full 180.degree. turning radius of
the distal tip of the imaging endoscope may not be necessary. In
those environments, the articulation joint may be replaced with a
flexible member such as a braided stent. FIG. 22 shows an imaging
endoscope 425 having a braided stent 430 as the articulation joint.
The braided stent extends between a distal tip 432 and a connector
434 that joins the proximal end of the stent 430 with the distal
end of a flexible shaft 436. A cover 438 extends over the flexible
shaft 436 and the braided stent 430. Control cables (not shown)
extend through a lumen of flexible shaft 436 and are used to pull
the stent 430 such that the distal tip 432 is oriented in the
desired direction. In addition, pulling all the control cables
simultaneously allows the distal tip of the endoscope to be
retracted.
[0098] FIG. 23 shows one method of securing the distal ends of the
control cables to a braided stent 430. The control cables 440a,
440b, 440c, 440d can be woven through the wires of the stent 430
and terminated by forming loops around the wires that comprise the
stent. Alternatively, the ends of the cables 440 can be soldered or
adhesively secured to the wires of the stent.
[0099] In some embodiments, the articulation joint is designed to
exert a restoring force so that imaging endoscope will tend to
straighten upon the release of tension from the control cables. In
other cases, it may be desirable to maintain the position of the
distal tip in a certain direction. In that case, a construction as
shown in FIG. 24 can be used. Here, the shaft of the imaging
endoscope includes an inner sleeve 450 that is overlaid with two or
more plastic spiral wraps 452, 454, and 456. Wrap 452 is wound in
the clockwise direction while wrap 454 is wound in the
counter-clockwise direction over the wrap 452 and the wrap 456 is
wound in the same direction as the first wrap 452. The wraps are
formed of a relatively coarse plastic material such that friction
is created between the alternatingly wound layers of the wrap. A
suitable material for the plastic wrap includes a braided polyester
or polyurethane ribbon. Upon tension of the imaging endoscope by
any of the control cables, the plastic spiral wraps will move with
respect to each other and the friction between the overlapping
wraps will tend to maintain the orientation of the imaging
endoscope in the desired direction. The endoscope will remain in
the desired direction until it is pulled in a different direction
by the control cables. Covering the alternatingly wound spiral
wraps 452, 454, and 456 is a braid 458. The braid is formed of one
or more plastic or wire threads wound in alternate directions. An
outer sleeve 460 covers the braid 458 to complete the shaft.
[0100] FIG. 25 shows another alternative embodiment of a shaft
construction used in an imaging endoscope according to the present
invention. The shaft includes a cover sheath 470 having bands of a
high durometer material 472 and a low durometer material 474 that
alternate around the circumference of the sheath 470. The high
durometer material and low durometer materials form longitudinal
strips that extend along the length of the shaft. Within the sheath
470 is a plastic spiral wrap 474 that prevents the shaft 470 from
crushing as it is bent in a patient's anatomy. The high durometer
materials add to the torque fidelity characteristics of the shaft.
The width of the high durometer material strips compared to the low
durometer material may be adjusted in accordance with the torque
fidelity characteristics desired.
[0101] During examination with the imaging endoscope, the physician
may need to twist the scope in order to guide it in the desired
direction. Because the outer surface of the scope is preferably
coated with a lubricant and it is round, it can be difficult for
the physician to maintain an adequate purchase on the shaft in
order to rotate it. As such, the imaging endoscope of the present
invention may include a gripper mechanism that aids the physician
in grasping the shaft for either rotating it or moving the shaft
longitudinally. One embodiment of a shaft gripping device is shown
in FIG. 26. Here, a gripper 500 comprises a unshaped member having
a pair of legs 502, 504 that are aligned with the longitudinal axis
of an imaging endoscope 20. At the distal end of the legs 502, 504
are two 90.degree. bends 506, 508. The gripper 500 includes a hole
505 positioned at the curved bent portion of the gripper that joins
the legs as well as holes in each of the 90.degree. sections 506,
508. The imaging endoscope passes through the holes such that the
gripper 500 is slideable along the length of the shaft portion of
the endoscope. The spring nature of the material used to fashion
the gripper causes the legs 502, 504 to be biased away from the
shaft of the endoscope. Only the friction of the opposing holes at
the bent portions 506, 508 prevent the gripper 500 from freely
sliding along the length of the shaft. On the inner surface of the
legs 502, 504 are a pair of touch pads 510, 512, having an inner
surface that is shaped to match the outer circumference of the
shaft portion of the endoscope. When the physician squeezes the
legs 502, 504 radially inward, the touch pads 510, 512 engage the
shaft such that the physician can push or pull the endoscope or
rotate it. Upon release of the legs 502, 504, the touch pads 510,
512 release from the surface of the shaft and the gripper 500 can
be moved along the length of the shaft to another location if
desired.
[0102] FIG. 27 shows a gripper similar to that of FIG. 26 with like
parts being identified with the same reference numbers. In this
embodiment, the gripper includes two hemispherical discs 520, 522,
positioned on the outside surface of the legs 502, 504. The
hemispherical surfaces 520, 522 are designed to fit within the hand
of the physician and increase the radial distance from the gripper
to the shaft such that it is easier to twist the shaft, if
desired.
[0103] FIG. 28 shows yet another alternative embodiment of a shaft
gripper. In this example, a gripper 550 comprises a u-shaped member
having a pair of legs 552, 554, that are oriented perpendicularly
to the longitudinal axis of the imaging endoscope 20. The legs 552,
554 include a recessed section 556, 558 that is shaped to receive
the outer diameter of the shaft portion of the endoscope. A
thumbscrew 560 is positioned at the distal end of the legs such
that the legs can be drawn together and cause the legs 554, 556 to
securely engage the shaft of the endoscope. Upon release of the
thumbscrew 560, the legs 554, 552 are biased away from the shaft
such that the gripper 550 can be moved. The shaft can be twisted by
rotating the legs 552, 554, with respect to the longitudinal axis
of the shaft.
[0104] FIG. 29 shows an alternative embodiment of the gripper 550
shown in FIG. 28. In this example, the gripper 580 includes a
u-shaped member having a pair of legs 582, 584. At the distal end
of each leg is a recess 586, 588 that is shaped to receive the
outer diameter of the shaft. The shaft is placed in the recesses
586, 588, and a thumbscrew is positioned between the ends of the
legs 582, 584, and the u-shaped bend in the gripper 580. By
tightening the thumbscrew 590, the legs are compressed against the
shaft of the imaging endoscope 20, thereby allowing the physician
to rotate the endoscope by moving the gripper 580.
[0105] In one embodiment of the invention the endoscope has a
movable sleeve that operates to keep the distal end of the
endoscope clean prior to use and covers the end of the scope that
was in contact with a patient after the scope has been used.
[0106] FIGS. 30A and 30B illustrate one embodiment of an endoscope
594 having a sponge 504 at its distal end. The sponge fits over the
endoscope and has a peel off wrapper that may be removed and water
or other liquid can be applied to the sponge. The water activates a
hydrophilic coating so that the distal end of the endoscope has an
increased lubricity. In addition, the sponge functions as a gripper
when compressed allowing the physician to pull and/or twist the
endoscope.
[0107] A collapsible sleeve 598 is positioned over the distal end
of the endoscope and can be retracted to expose the lubricated
distal tip of the probe. In one embodiment, the sleeve 598 is
secured at its distal end to the sponge 594 and at its proximal end
to the breakout box. Moving the sponge proximally retracts the
sleeve so that the endoscope is ready for use. After a procedure,
the sponge 594 is moved distally to extend the sleeve over the
distal end of the endoscope. With the sleeve extended, any
contaminants on the probe are less likely to contact the patient,
the physician or staff performing the procedure.
[0108] In some instances, it may be desirable to limit the amount
of heat that is dissipated at the distal end of the imaging
endoscope. If light emitting diodes are used, they generate heat in
the process of producing light for illumination. Similarly, the
image sensor generates some heat during operation. In order to
limit how hot the distal end of the endoscope may become and/or to
provide for increased life for these components, it is necessary to
dissipate the heat. One technique for doing so is to fashion a heat
sink at the distal tip of the imaging endoscope. As shown in FIG.
31, a distal tip 600 includes a cap 602 and a heat dissipating
section 604 that is made of a heat dissipating material such as a
biocompatible metal. The heat dissipating section 604 includes a
semicircular opening 606 having a relatively flat base 608 that
extends approximately along the diameter of the heat dissipating
section 604. The flat base 608 forms a pad upon which electrical
components such as the LEDs and image sensor can be mounted with a
thermally conductive adhesive or other thermally conductive
material. The heat generating devices will transfer heat generated
during operation to the heat dissipating section 604. The distal
cover 602 covers the distal end of the heat dissipating section 604
in order to prevent the heat dissipating section 604 from touching
the tissue in the body as well as to protect the body as the
imaging catheter is moved in the patient. Prisms, lenses, or other
light bending devices may be needed to bend light entering the
distal end of the endoscope to any imaging electronics that are
secured to the relatively flat base 608 of the heat dissipating
section 604.
[0109] FIG. 32 shows a heat dissipating distal tip of an endoscope
wherein the distal tip does not include a cover but is molded from
a single piece of heat dissipating material such as a biocompatible
metal. The heat dissipating section 620 again includes a
semicircular opening with a relatively flat surface 622 that
extends along the diameter of the section and on which heat
generating electronic devices can be mounted. With a semicircular
opening formed in the distal end of the heat dissipating distal tip
620, the illumination mechanism and image sensor are mounted on the
flat surface 622. The irrigation port is oriented to direct water
over the hemispherical cutout in order to clean the illumination
mechanism and image sensor or image sensor lenses.
[0110] In yet another embodiment of the invention, the imaging
devices at the distal end of the endoscope can be cooled by air or
water passed through a lumen to the end of the endoscope and vented
outside the body. For example, air under pressure may be vented
through an orifice near the imaging electronics. The expansion of
the air lowers its temperature where it cools the imaging
electronics. The warmed air is then forced to the proximal end of
the endoscope through an exhaust lumen. Alternatively, the
endoscope may include a water delivery lumen that delivers water to
a heat exchanger at the distal tip. Water warmed by the electronic
components in the distal tip is removed in a water return
lumen.
[0111] FIG. 33 shows an alternative embodiment of the heat
dissipating distal tip shown in FIG. 31. In this example, the heat
dissipating distal tip 640 has a number of scalloped channels 642
positioned around the circumference of the distal tip. The
scalloped channels 642 increase the surface area of the heat
dissipating distal tip, thereby further increasing the ability of
the tip to dissipate heat from the illumination and imaging
electronic devices.
[0112] Although the present endoscopic imaging system has many
uses, it is particularly suited for performing colonoscopic
examinations. In one embodiment, a 10-13 mm diameter prototype
having a 0.060 inner spiral wrap with a pitch of {fraction (1/4)}
inch and coated with a hydrophilic coating was found to have a
coefficient of friction of 0.15 compared to 0.85 for conventional
endoscopes. In addition, the endoscope of the present invention
required 0.5 lbs. of force to push it through a 2-inch U-shaped
bend where a conventional endoscope could not pass, through such a
tight bend. Therefore, the present invention allows colonoscopes to
be made inexpensively and lightweight so that they are more
comfortable for the patient due to their lower coefficient of
friction and better trackability.
[0113] In addition to performing colonoscopies, the endoscopic
imaging system of the present invention is also useful with a
variety of surgical devices including: cannulas, guidewires,
sphincterotomes, stone retrieval balloons, retrieval baskets,
dilatation balloons, stents, cytology brushes, ligation devices,
electrohemostasis devices, sclerotherapy needles, snares and biopsy
forceps.
[0114] Cannulas are used with the endoscopic imaging system to
cannulate the sphincter of Odi or papilla to gain access to the
bile or pancreatic ducts. Guidewires can be delivered down the
working channel of the endoscope and used as a rail to deliver a
surgical device to an area of interest. Sphincterotomes are used to
open the papilla in order to place a stent or remove a stone from a
patient. Stone retrieval balloons are used along with a guidewire
to pull a stone out of a bile duct. Retrieval baskets are also used
to remove stones from a bile duct. Dilatation balloons are used to
open up strictures in the gastrointestinal, urinary or pulmonary
tracts. Stents are used to open up strictures in the GI, urinary or
pulmonary tracts. Stents can be metal or plastic, self-expanding or
mechanically expanded, and are normally delivered from the distal
end of a catheter. Cytology brushes are used at the end of
guidewires to collect cell samples. Ligation devices are used to
ligate varices in the esophagus. Band ligators employ elastic bands
to cinch varices. Electrohemostasis devices use electrical current
to cauterize bleeding tissue in the GI tract. Sclerotherapy needles
are used to inject coagulating or sealing solutions into varices.
Snares are used to remove polyps from the GI tract, and biopsy
forceps are used to collect tissue samples.
[0115] Examples of specific surgical procedures that can be treated
with the endoscopic imaging system of the present invention include
the treatment of gastroesophageal reflux disease (GERD) by the
implantation of bulking agents, implants, fundoplication, tissue
scarring, suturing, or replacement of valves or other techniques to
aid in closure of the lower esophageal sphincter (LES).
[0116] Another example of a surgical procedure is the treatment of
morbid obesity by deploying implants or performing reduction
surgery, gastric bypass and plication or creating tissue folds to
help patients lose weight.
[0117] Endoscopic mucosal resection (EMR) involves the removal of
sessile polyps or flat lesions by filling them with saline or the
like to lift them prior to resection. The endoscope of the present
invention can be used to deliver needles, snares and biopsy forceps
useful in performing this procedure.
[0118] In addition, the endoscopic imaging system of the present
invention can be used to perform full-thickness resection (FTRD) in
which a portion of a GI tract wall is excised and the wounds healed
with staplers or fasteners. Finally, the endoscopic imaging system
of the present invention can be used to deliver sclerosing agents
to kill tissues or drug delivery agents to treat maladies of
internal body tissues.
[0119] While the preferred embodiment of the invention has been
illustrated and described, it will be appreciated that various
changes can be made therein without departing from the scope of the
invention. For example, although some of the disclosed embodiments
use the pull wires to compress the length of the endoscope, it will
be appreciated that other mechanisms such as dedicated wires could
be used. Alternatively, a spring can be used to bias the endoscope
distally and wires used to compress the spring thereby shortening
the length of the endoscope. Therefore, the scope of the invention
is to be determined from the following claims and equivalents
thereof.
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