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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to flexible endoscopic probes, and
more particularly to an endoscopic probe wherein an optical lens is
mechanically engaged to the end of a coherent optical fiber at the tip of
the probe, and wherein further component parts of the endoscope may also
be engaged together at the tip of the probe utilizing a mechanical
engagement means, such that the endoscope is structurally durable and can
be repeatedly sterilized in an autoclave without damage to the endoscope
and its components throughout its useful lifetime.
2. Description of the Prior Art
Prior art endoscopic probes contain a plurality of components disposed
within a flexible tubular member. A typical prior art endoscopic probe is
described in U.S. Pat. No. 5,456,245, issued Oct. 10, 1995 to Bornhop et
al., entitled "Flexible Endoscope Probe and Method of Manufacture," in
which potting materials and adhesives are used to engage various
components at the tip of the probe and to seal the probe. A significant
problem with such prior probes is infection control during usage of the
probe, and the sterilization of such probes when they are used once. An
article describing such infection control problem and the disinfecting or
sterilizing of probes is printed in the American Journal of Infection
Control, entitled "APIC Guidelines for Infection Prevention and Control in
Flexible Endoscopy," Vol. 22, February, 1994, pages 19-38, written by M.
A. Martin and M. Reichelderfer.
SUMMARY OF THE INVENTION
The flexible endoscopic probe of the present invention includes
mechanically engaged components within the tip of the probe. That is, the
probe includes a viewing system including a coherent optical fiber having
a lens that is mechanically engaged to the tip thereof. Additionally, a
metal sleeve may be utilized at the tip of the probe to mechanically bind
all of the components within the probe at its tip. Potting materials or
adhesives may also be utilized to seal the components within the probe
tip. Owing to the usage of mechanical binding methods, the probe is more
durable and may be heat sterilized in an autoclave, or the like, in order
to permit repeated usage of the probe.
It is an advantage of the endoscopic probe of the present invention that it
includes a lens component that is mechanically engaged to an optical
fiber.
It is another advantage of the present invention that it includes a lens
which is engaged to an optical fiber with a minimal use of sealants.
It is a further advantage of the present invention that all of the
components of the endoscopic probe are engaged at the tip thereof
utilizing a mechanical engagement means.
It is yet another advantage of the present invention that the components of
the endoscopic probe are engaged at the tip thereof with a minimal use of
sealants or potting materials.
It is yet a further advantage of the present invention that it may be
repeatedly sterilized in an autoclave without significant degradation in
its performance characteristics throughout the useful lifespan of the
product.
These and other features and advantages of the present invention will
become well understood upon reading the detailed description of the
invention as set forth below.
IN THE DRAWINGS
FIG. 1 is a perspective view of the endoscopic probe system of the present
invention;
FIG. 2 is an enlarged perspective view of the tip of the endoscopic probe
of the present invention;
FIG. 3 is an end elevational view of the probe tip depicted in FIG. 2;
FIG. 4 is a perspective view of a first preferred embodiment of the tip of
the optical fiber component of the endoscope of the present invention;
FIG. 5 is a side cross-sectional view of the tip of the optical fiber
portion of the present invention, taken along lines 5--5 of FIG. 4;
FIG. 6 is a side cross-sectional view depicting a step in the manufacturing
of the optical fiber tip of the present invention;
FIG. 7 is a side cross-sectional view depicting another step in the
manufacturing of the optical fiber tip of the present invention;
FIG. 8 is a side cross-sectional view of the optical fiber tip of the
present invention at the completion of manufacturing;
FIG. 9 is a side cross-sectional view of the endoscope tip of the present
invention, depicting a step in the manufacturing thereof;
FIG. 10 is a side cross-sectional view of the endoscope tip of the present
invention, depicting a further step in the manufacturing thereof;
FIG. 11 is a side cross-sectional of the tip of the endoscopic probe of the
present invention upon completion of manufacturing;
FIG. 12 is a perspective view of an alternative embodiment of the tip of
the optical fiber component of the endoscope of the present invention; and
FIG. 13 is a side cross-sectional view of the tip depicted in FIG. 12,
taken along lines 13--13 of FIG. 12.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 depicts the endoscopic probe system 10 of the present invention
including a long, thin, flexible endoscopic probe 12 having a proximal end
14 and a distal end 16 which terminates in a probe tip 18. As is well
known in the art the probe 12 is formed using a flexible extrusion tube
17, such as a PEBAX tube, having a plurality of tubular passages formed
axially therewithin for the insertion of various components of the probe
12, from the proximal end 14 to the distal end 16; PEBAX is a trademark of
Ato Shimie, Curbevole, France. The probe tip 18 comprises the end tip of
the PEBAX tube 17 with various components as are herein described.
The probe system 10 includes an illumination system 19 including a light
source 20 that projects viewing light through an optical fiber 22 to a
light emitting tip 24 engaged in the tip 18 of the endoscopic probe 12.
Such illumination systems 19 are well known in the prior art which also
may include two or more light emitting optical fibers with individual
tips. The probe system 10 also includes a viewing system 26 which receives
imaging data through a coherent optical fiber 28 that passes through the
probe 12 to a tip 30 disposed in the probe tip 18. The tip 30 includes an
optical lens 50 as is known in the art. The system 10 may also include
further components as are known in the art, such as an irrigation system
31 or a tissue sampling system 32 which operates through a hollow tubular
passage 34 of the extrusion tube 17 and terminates at a passage tip 36.
Such irrigation systems 31 and tissue sampling systems 32 are well known
in the prior art. Also known in the prior art, and not depicted herein for
clarity sake, are probe movement systems, such as wires that pass through
the probe 12 to control the movement of the distal end 16 of the probe 12.
FIGS. 2 and 3 depict the distal end 16 of the probe 12, wherein FIG. 2 is
an enlarged perspective view thereof and FIG. 3 is an end elevational view
thereof. As depicted in FIGS. 2 and 3, the distal end 16 includes a
cylindrical outer sleeve member 40 that surrounds and mechanically
compresses the tip end 18 to hold the light emitting probe tip 24, the
video imaging tip 30 and the tissue probe passage tip 36 within the
extrusion tube 17. As can be seen from FIGS. 2 and 3, the sleeve 40 is
radially inwardly mechanically deformed at its leading edge 44 to
accomplish the mechanical holding of the tips 24, 30 and 36 together
within the tip 18. A cylindrical sleeve 38 is preferably inserted within
the tip 36 of the passage 34 to avoid compression of the walls of the
flexible tube into the passage tip 36. The manufacturing process for
creating the deformation of the edge 44 of the sleeve 40 to accomplish the
mechanical holding of the three tips 24, 30 and 36 is discussed
hereinbelow with the aid of FIGS. 8, 9 and 10.
FIGS. 4 and 5 depict a first preferred engagement method of the optical
lens 50 to the coherent optical fiber 28, wherein FIG. 4 is a perspective
view of the video imaging tip 30, and FIG. 5 is a side cross-sectional
view taken along lines 5--5 of FIG. 4. The video imaging tip 30 includes
the optical lens 50 that is fixedly engaged to the end of the coherent
optical fiber 28 utilizing a mechanical engagement that is created by
using a deformable sleeve 52 preferably composed of a metal such as a
copper based alloy or gold or other suitable material as would be known to
those skilled in the art. As depicted in FIGS. 4 and 5, optical lens 50 is
preferably formed as a solid cylindrical lens body having a convex
exterior surface 58 and a flat interior surface 60.
The interior face 60 of the lens 50 is butted against the end 64 of the
coherent optical fiber 28. Such lenses 50 and coherent optical fibers 28
are well known in the endoscopic art, and are typically engaged together
utilizing a transparent epoxy type adhesive. A significant feature of the
present invention is that the lens 50 is mechanically engaged to the
coherent optical fiber end 64 utilizing the cylindrical sleeve 54. To
accomplish this mechanical engagement, the inner diameter of the
cylindrical sleeve 54 closely matches the outer diameter of the optical
fiber 28 and lens 50, such that a generally snug fit is obtained. The
outer edge 68 of the sleeve 54 is mechanically deformed inwardly to
frictionally engage the outer surface of the cylindrical lens 50, and the
shaft of the sleeve 54 is crimped 70 to engage the coherent optical fiber
28. The preferred device to accomplish the mechanical deformation of the
outer edge 68 of the sleeve 54 is disclosed in issued U.S. Pat. No.
5,305,406, the contents of which are incorporated herein as though set
forth in full. The preferred method for the engagement of the lens 50 to
the optical fiber end 64 utilizing the deformable cylindrical sleeve 54 is
next discussed with the aid of FIGS. 6, 7 and 8.
FIGS. 6, 7 and 8 depict the manufacturing steps that are utilized in the
preferred manufacturing method for the engagement of the lens 50 to the
optical fiber end 64. Each of FIGS. 6, 7 and 8 is a cross-sectional view
that is similar to FIG. 5, however, the optical fiber 26 and sleeve 54 are
preferably oriented vertically to utilize gravitational force to simplify
the assembly method. As depicted in FIG. 6, the cylindrical sleeve 54 is
inserted over the end 64 of the coherent optical fiber 28. The sleeve 54
projects upwardly from the end 64 a sufficient distance such that the lens
50 may be placed within the sleeve 54. The sleeve 54 is then adjusted
vertically, such that a small tip portion 72 of the lens 50 projects
outwardly from the upper end 76 of the sleeve 54. When the sleeve 54 is in
the proper vertical orientation to create the small lens projection 72, a
standard crimping device 80 is utilized to provide a lateral force 82
against the sides of the sleeve 54 to depress the sleeve sides inwardly to
form the crimp 70 (see FIG. 7), whereby the optical fiber 28 and the
sleeve 54 become mechanically engaged together.
The outer end 76 of the sleeve 54 is next deformed (as sleeve end 68 is
depicted in FIG. 5) to engage the lens 50 to the end 64 of the optical
fiber 28. As is depicted in FIG. 7 the sleeve 54 is engaged to the optical
fiber 28 by the crimp 70 and the lens 50 is loosely engaged in the outer
end of the sleeve 54, such that a portion 72 of the lens 50 projects
beyond the upper end 76 of the sleeve 54. As indicated hereinabove, an
impact mounting assembly device, such as is described in U.S. Pat. No.
5,305,406 is next utilized to mechanically engage the lens 50 within the
sleeve 54. The lens mounting method involves the placement of the optical
fiber 28 with its crimp-attached sleeve 54 within a holding notch 90
formed in a holding member 92 of an impact assembly device, such that the
rearward end 96 of the sleeve 54 rests against an inner surface 100 of the
holding member 92, while the optical fiber 28 passes through the slot 90.
Thereafter, an impact punch head 106 of the impact mounting device is
moved into position 110 against the projecting distal end 76 of the sleeve
54. The impact head 106 is formed with a conical recess 114 defined by
inwardly converging sidewalls 118. The sidewalls 118 converge to a
cylindrical cavity 122 defined by sidewalls 126, which are dimensioned
such that the diameter of the cylindrical cavity 122 is larger than the
diameter of the lens 50. It is therefore to be understood that when the
impact punch head 106 is forcefully directed 110 against the sleeve 54,
that the sidewalls 118 of the conical cavity 114 will make an impact
contact with the end 76 of the sleeve 54, while the lens 50 will project
untouched into the cylindrical cavity 122. The contact of the rearward end
96 of the sleeve 54 with the surface 100 of the holding member 92 acts to
prevent the sleeve 54 from moving rearwardly when it is impacted at the
outer end 76 by the impact head 106.
FIG. 8 depicts the finished mechanical engagement of the lens 50 to the
optical fiber 26. As shown in FIG. 8, the outer end 76 (now shown in
phantom) of the sleeve 54 has been deformed to create the inwardly
projecting end 68, wherein a deformed portion 136 of the tip of the sleeve
54 has been mechanically depressed inwardly into frictional engagement
with the cylindrical side surface 140 of the lens 50. In this manner, the
lens 50 is mechanically, frictionally engaged in a butted relationship
with the end 64 of the optical fiber 28.
Various sealants and potting compounds that are well known to those skilled
in the art can be advantageously utilized along with the mechanical
engagement methods described hereabove. Specifically, a liquid sealant
formulation 142 can be inserted into the circumferential gap 144 between
the lens 50 and the sleeve 54, as depicted in FIG. 7. Thereafter, the
outer end 76 of the sleeve 54 is deformed, as discussed above with regard
to FIG. 8, and the sealant 142 thus remains within the gap 144 to provide
a sealed mechanical engagement of the lens 50 within the sleeve 54.
The manufacturing method for the endoscope of the present invention is
depicted in FIGS. 9, 10 and 11, which manufacturing steps are similar to
the manufacturing steps for the viewing system optical fiber probe tip 30.
As depicted in FIG. 9, a sleeve 40 surrounds the distal end 16 of the
endoscopic probe 12. The cylindrical sleeve 38 is disposed in the end 36
of the tubular passage 34, as discussed above, and the coherent optical
fiber 28 with its mechanically engaged lens 50 projects through a tubular
passage 150 axially formed through the PEBAX tube 17. The illumination
optical fiber disposed within its tubular passageway is not depicted in
the cross sectional view of FIG. 9. In the preferred endoscopic probe
manufacturing method of the present invention, the cylindrical sleeve 40
is placed around the tip 16 of the probe 12 such that end 17 of the PEBAX
tube projects slightly outwardly from the outer end 154 of the sleeve 40.
A standard crimping means 158 is then utilized to apply a radially inward
force 160 against the sides of the sleeve 40 to crimp 164 the sleeve 40
into a mechanical engagement with the tip 16 of the probe 12.
As depicted in FIG. 10, an impact mounting device is next utilized to
further mechanically engage the sleeve 40 to the probe tip 16. As depicted
in FIG. 10, the probe 12 with the sleeve 40 engaged by the crimp 164 is
placed within a slot 168 formed in a holding member 172 of an impact mount
device. A suitable impact mount device is described in U.S. Pat. No.
5,305,406, as has been mentioned and incorporated hereabove. An impact
head 176 of the impact mounting device is next brought into contact with
the upper end 154 of the sleeve 40. The impact head is formed with a
conical cavity 180 defined by inwardly depending sidewalls 182 which
terminate in a cylindrical cavity 184 defined by cylindrical sidewalls
186. It is to be understood that the diameter of the cylindrical cavity
184 is greater than the diameter of the tip 17 of the probe 12, whereas
the conical sidewalls 182 will make impact contact with the upper end 154
of the sleeve 40. It is to be further understood that when the impact head
176 makes impact contact with the outer end 154 of the sleeve 40 that the
outer end 154 will be deformed inwardly to make frictional contact with
the outer surface 190 of the probe tip 16. The rearward end 194 of the
sleeve 40 rests upon the surface 196 of the holding member 172, such that
the sleeve is immovable during the impact head contact.
FIG. 11 depicts the probe tip 16 following the impact mounting of the
sleeve 40. As depicted in FIG. 11, the sleeve end 154 (now shown in
phantom) has been inwardly deformed, such that an inner portion 198 of the
sleeve 40 makes frictional contact with the outer surface 190 of the probe
tip 16, and the outer end 44 of the sleeve 40 is deformed, as previously
described. In order to achieve a superior engagement of the impacted
sleeve end 44 with the probe tip 16, the small cylindrical sleeve 38 is
placed within the end 36 of the tube passage 34 prior to impact mounting.
The sleeve 38 serves to provide mechanical rigidity to the outer end 36 of
the tubular passage 34, which functions to prevent the collapse of the
outer end 36 of the tubular passage 34 during impact mounting.
Various sealants and potting compounds that are well known to those skilled
in the art can also be advantageously utilized along with the mechanical
engagement methods described hereabove. Specifically, a liquid sealant
formulation 200 can be inserted into the circumferential gap 202 between
the surface 190 and the sleeve 40, as depicted in FIG. 10. Thereafter, the
outer end 154 of the sleeve 40 is deformed, as discussed above with regard
to FIG. 11, and the sealant 200 thus remains within the gap 202 to provide
a sealed mechanical engagement of the probe tip 16 within the sleeve 40.
An alternative viewing lens tip 220 of the present invention is depicted in
FIGS. 12 and 13, wherein FIG. 12 is a perspective view and FIG. 13 is a
side cross-sectional view taken along lines 13--13 of FIG. 12. As depicted
in FIGS. 12 and 13, a lens 50, being generally identical to lens 50
depicted FIGS. 4 and 5, and having a convex outer surface 58 and a plane
inner surface 60 is butted against the end 64 of a coherent optical fiber
28. The lens 50 is held in position against the end 64 utilizing a
deformable sleeve 54, as has been described hereabove with reference to
FIGS. 4 and 5. The significant difference between this tip embodiment 220
and the tip embodiment 30 depicted in FIGS. 4 and 5 is that the lens 50 is
contained within the deformed forward end 68 of the sleeve 54. That is,
the lens 50 does not have an outwardly projecting portion 72 as depicted
in FIGS. 4 and 5. Rather, the lens 50 is recessed within the crimped
forward end 68 of the sleeve 54, as depicted in FIGS. 12 and 13. A method
for manufacturing the tip 220 commences by deforming the forward edge 68
of the sleeve 54, preferably utilizing an impact mounting assembly device
such as is described in U.S. Pat. No. 5,305,406. After the front end 68 of
the sleeve 54 has been deformed, the lens 50 is placed within the sleeve
54, followed by the optical fiber 28. Thereafter, the sleeve 54 is crimped
70 to hold the sleeve and the optical fiber 28 together. In this manner,
the lens 50 is mechanically held within the sleeve 54 in a butted
relationship with the end 64 of the optical fiber 28.
It is therefore to be understood that the endoscopic probe 12 of the
present invention includes the mechanical engagement of various components
at the tip of the probe. The present invention is therefore repeatedly
heat sterilizable utilizing an autoclave or similar apparatus, whereas
prior art devices that use adhesives for primary engagement purposes
cannot be repeatedly heat sterilized because of the adverse effect of heat
upon the adhesives. It is to be further understood that the present
invention includes both the impact mounting of the lens 50 to the optical
fiber 28 in creating the imaging system, and the impact mounting of the
outer sleeve 40 to the tip 18 of the probe 12 to securely engage the
various components within the tip 18.
While the present invention has been shown and described with reference to
certain preferred embodiments, it will be understood by those skilled in
the art that certain alterations and modifications can be made herein
without departing from the true spirit and scope of the invention.
Therefore, the following claims are intended to be interpreted to cover
all such altered and modified devices that nevertheless include the true
spirit and scope of the invention.
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