Endoscope having a deflectable distal section and a semi-rigid proximal section

An endoscope having an elongated shaft which terminates in a deflectable distal tip is shown. The elongated shaft includes a first elongated sheath tube having a deflectable distal section. The deflectable distal section terminates in a distal tip having a triangular shaped cross-sectional area. The elongated shaft also includes a second semi-rigid elongated tube which is shorter in length than the first elongated sheath tube. The difference in length enables the deflectable distal section to extend beyond the end of the second semi-rigid elongated sheath tube and to be deflectable. The second semi-rigid elongated sheath tube encloses the proximal section of the first elongated sheath tube. The second semi-rigid elongated sheath tube has a generally rounded cross-sectional area which is slightly greater than that of the cross-sectional area of the first elongated sheath tube which enables the distal end of the second semi-rigid elongated sheath tube to enclose and pass therethrough the first elongated sheath tube. A method for performing a procedure in a cavity or passageway is also shown. A method for casting a housing around an endoscope frame is shown. An image means for an instrument having a rod-like image transferring system which is rigidly attached at a selected location is shown.

BACKGROUND OF THE INVENTION 
1. Field of Invention 
This invention relates to an endoscope which is used for performing a 
procedure inside a body cavity or passageway and is more particularly 
directed towards an endoscope in the form of a mini-rigid ureteroscope 
which is used to perform medical procedures classified as diagnostic 
endoscopic examinations and therapeutic endoscopic procedures. The 
mini-rigid ureteroscope has an elongated shaft including a first elongated 
sheath tube having a deflectable distal section and a second elongated 
semi-rigid sheath tube which encloses a major portion of the first 
elongated sheath tube. The deflectable distal section extends beyond the 
distal end of the second semi-rigid elongated sheath tube. The endoscope 
is adapted to be inserted into the ureter of a patient for performing a 
medical examination and/or procedure within the ureter. This invention 
also relates to a method for casting a housing of a predetermined shape 
around an endoscope frame to form a fluid tight seal around working 
channels, viewing means for a fiber optic image bundle channel having a 
fiber optic image bundle and fiber optic light carrying means, all forming 
a part of the endoscope. This invention also relates to an image means for 
an instrument having a rod-like image transferring means wherein the 
rod-like image transferring means is rigidly attached to the instrument at 
a selected location along its length and wherein a slidably supporting 
means slidably supports the rod-like image transferring means at least at 
one location along the length to permit relative movement between the 
rod-like image transferring means and the instrument. 
2. Description of the Prior Art 
Endoscopes with an elongated shaft for viewing a body canal and for 
performing a surgical procedure within the body canal are known in the 
art. Typical of these devices, is an endoscope with tapered shaft of U.S. 
Pat. No. 4,986,258 which replaced withdrawn U.S. Pat. No. 4,961,414 and 
rigid endoscope with flexible tip covered in U.S. Pat. No. 4,802,461. A 
mini-scope catheter adapted to perform diagnostic procedures in smaller 
body parts, such as, for example, the bile duct or interior of the gall 
bladder, and which is constructed to allow the operator to control the 
deflection of a catheter tip is disclosed in U.S. Pat. No. 4,899,732. 
The endoscope with tapered shaft disclosed in U.S. Pat. No. 4,986,258 
utilizes a plurality of stages which are either step tapered or uniformly 
tapered to provide a distal section, a central section and a proximal 
section. The various stages or sections may be formed by a plurality of 
coaxially aligned tubes of decreasing diameters or could be formed of a 
single elongated shaft which is machined to provide the desired tapered 
surface along its length with the distal end having the smaller 
geometrical dimension. The transition zones between the three stages of 
the endoscope occur at about each third of the length and the transition 
for a two stage endoscope is approximately at the one half length or 
mid-point location. 
U.S. Pat. No. 4,986,258 discloses that the final stage may include a 
flexible tip portion at the distal end of the shaft which is controllable 
from an endoscope handle. A mechanism for deflecting the flexible tip of a 
rigid endoscope, which could be used for such a flexible tip in an 
endoscope with taper shaft, is disclosed in U.S. Pat. No. 4,802,461 noted 
above. The tip end of the tube is barely flexible, relative to the length 
of the tube. Wires connected to opposite ends of the flexible tip provide 
the user with the means to control the flexing of the distal tip. 
Also, U.S. Pat. No. 4,899,732 discloses a catheter, which has a deflectable 
catheter tip and which includes at least one lumen, which can be used to 
receive a stylet or to pass a contrast medium. In addition, the 
mini-catheter includes two optical filament channels, one for carrying 
light to the distal end and the other for transmitting an optical image to 
the proximal end of the catheter. 
The cross-sections of each the above described endoscopes and mini-scope 
are generally circular in shape and provide a distal tip which can be 
utilized to be inserted in to the orifice of the body canal or duct, as 
the case may be. 
It is also known in the art to utilize a ureteroscope to perform certain 
procedures in the urethra, bladder, ureter or kidney. Generally, 
ureteroscopes are used to view the ureter or perform procedures in the 
ureter. As such, the endoscopes include a semi-rigid elongated shaft to 
enable the urologist or user to insert the distal tip through the urethra 
orifice and to advance the same through the bladder and through the 
intra-mural ureter to some location in the ureter. 
Surgical procedures may be performed within the urinary system such as 
destroying and/or removing bladder stones, ureteral stones, kidney stones 
or examining calyces of the kidney. It is also known to use mechanical 
accessories or working tools such as lithotriptors, electrohydraulic 
probes, stone baskets or laser fiberguides to break up a stone and to 
perform other known procedures. The flexibility of the tip and the length 
of the semirigid section are important features of a ureteroscope in the 
urology field. The reason that the above features are important is that 
the anatomical path of the ureter between the bladder and the kidney is 
not a straight line and, in some cases, can be quite torturous. 
Ureteroscope sheaths for performing procedures in the ureter are known in 
the art. Typical of such ureteroscope sheaths are devices offered for sale 
and sold by the CIRCON ACMI Division of Circon Corporation, which are 
identified as Catalog Numbers HUS-10S and HUS-10L. These Catalog Number 
devices are basically the same ureteroscope sheath with Catalog Number 
HUS-10L having a longer elongated shaft to enable the urologist to advance 
the ureteroscope sheath further into the ureter. 
The Catalog Numbers HUS-10S and HUS-10L ureteroscopes are constructed to 
have a semi-rigid section which is operatively attached to a relatively 
rigid proximal section forming a two diameter stepped elongated shaft. The 
two sections are joined with the proximal end of the semi-rigid section 
mechanically attached to the distal end of the relatively rigid proximal 
section at a point approximately midway along the elongated shaft. A 
tapered joint or a step-tapered joint is provided depending on the 
manufacturing assembly of the ureteroscope sheath. The degree of taper at 
the transitional zone or joint area is controlled by metal polishing and 
other known manufacturing techniques. 
Each of the above known endoscopes, flexible mini-catheters and the 
ureteroscope sheaths have at least one working channel. The endoscopes and 
mini-catheter include a fiber optic image bundle. A fiber optic light 
carrying means may be dispersed around the working channels and fiber 
optic image bundle channel or may be located in a separate dedicated fiber 
optic light bundle channel. 
None of the known prior art devices disclose an endoscope having an 
elongated shaft wherein one transitional zone exists between a semi-rigid 
proximal section and deflectable distal section wherein the transitional 
zone is located generally in the distal area, such as the first quarter 
length, of the elongated shaft, as measured from the distal tip. Further, 
the endoscope of the present invention may have the flexible distal 
section thereof terminate in a distal portion which has a geometrically 
shaped cross-sectional area having at least one protuberance. In the 
preferred embodiment, the distal section is triangular shaped and has a 
plurality of working channels, which may be of the same or different sizes 
and shapes, a fiber optic image bundle channel having a fiber optic image 
bundle and a fiber optic light carrying means. The endoscope of the 
present invention may be used to view the interior of a cavity or 
passageway and the working channels may be utilized for performing 
procedures within the cavity or passageway. 
As the state-of-the-art advances in the ureteroscopy field, it has 
developed that endoscopes having a shorter elongated shaft wherein the 
distal section of the shaft is flexible and the proximal section of the 
shaft is semi-rigid are preferred. Specifically, such endoscopes are 
preferred for performing visual examinations within the urinary system and 
for performing various procedures and providing treatment for diseases of 
the urinary tract. Typical of articles which disclose the use of a rigid 
endoscope in the management of ureteral diseases are: (1) URETEROSCOPE 
WITH RIGID INSTRUMENTS IN THE MANAGEMENT OF DISTAL URETERAL DISEASE by 
Tobias M. Goodman which appeared in the Journal of Urology, August, 1984, 
Volume 132, at pages 250 (The "Goodman Publication"); and (2) URETERAL 
LASER LITHOTRIPSY USING THE PULSOLITH by Demetrius H. Bagley, M.D., 
Michael Grasso, M.D., Mohammed Shalaby, M.D. and Magdy Abass El-Akkad, 
M.D. which appeared in the Journal of Endourology, Volume 3, Nov. 1, 1989, 
at Pages 91-98 (The "Bagley et al. Publication") 
The Goodman Publication discloses that the rigid ureteroscope allows for 
ureteroscopic manipulation of the ureter because of the anatomical 
arrangement of the body. Ureteroscopy with a rigid instrument usually is 
performed with the patient under anesthesia. The Goodman Publication also 
describes the procedure is performed by introducing the distal tip of the 
rigid ureteroscope into the urethra and passing the instrument 
transurethrally. The ureteroscope is then introduced into the ureteral 
orifice. Usually, this is done visually through an eyepiece or by 
observing a video image developed by a video camera attached to the 
ureteroscope. The Goodman Publication specifically discloses the necessity 
of having the exterior of the sheath of the ureteroscope very smooth and 
of small caliber such that the ureter will adjust to the increasing size 
of the instrument as it is transversed throughout the ureter. The 
procedure described in the Goodman Publication demonstrates the 
applicability of ureteroscopy to every day problems encountered by a 
urologist. 
The Bagley et al. Publication discloses use of a Pulsolith.TM. Laser as a 
highly effective tool for the destruction of ureteral calculi including 
those of calcium oxalate monohydrate. The small flexible fibers required 
to be used with the laser are delivered with rigid or flexible endoscopes 
throughout the upper urinary tract. The Bagley et al. Publication 
discloses that the endoscopic access to the distal ureteral calculi with 
rigid instruments is extremely successful. However, when calculi are 
located in mid or upper ureteral locations, flexible ureteroscopy is 
generally more successful in accessing those more proximal locations. 
SUMMARY OF THE INVENTION 
The present invention discloses a novel, unique and improved endoscope 
which is capable of being used in ureteroscopy in the management of 
ureteral disease. In the preferred embodiment, the endoscope is a 
mini-rigid ureteroscope which includes an elongated shaft wherein the 
shaft includes a first elongated sheath tube having a selected length and 
includes a deflectable distal section. The deflectable distal section has 
at its distal end a triangular cross-sectional area of a selected 
geometrical dimension which terminates in a distal tip. The elongated 
shaft includes a second semi-rigid elongated sheath tube having a 
predetermined length which is greater than one-half of the selected length 
and less than the selected length. This essentially places the transition 
zone between the sheath tubes in the distal area of the endoscope. The 
second semi-rigid elongated shaft is positioned over and encloses the 
proximal section of the first elongated sheath tube with a deflectable 
distal section extending beyond the second semi-rigid elongated sheath 
tube. The second semi-rigid elongated sheath tube has a cross-sectional 
shape sufficient to pass the first elongated sheath tube therethrough. 
A method is shown for casting a housing around an endoscope frame. The 
method includes the step of assembling an endoscope frame comprising a 
proximal end of an elongated shaft having a first working channel, a 
second working channel, a fiber optic image bundle channel and fiber optic 
light carrying means which extends into and which is interspersed within 
the elongated shaft and around the first working channel, the second 
working channel and the fiber optic image bundle channel. Each of the 
working channels and the fiber optic light carrying means extend in a 
predetermined direction from the distal end of the elongated shaft to a 
preselected location wherein each of the channels are terminated in an 
input opening means, wherein the fiber optic image bundle terminates in a 
viewing means and wherein the fiber optic light carrying means terminates 
in a light connecting means. 
The next step is casting with a curable material a housing having a 
predetermined shape and exterior outer surface around the endoscope frame 
including the proximal end of the elongated shaft, the first working 
channel, the second working channel, the fiber optic image bundle channel 
and the fiber optic light carrying means such that the input opening means 
of each working channel and the light connecting means of the fiber optic 
light carrying means extend through the exterior outer surface of the 
housing at separate and distinct locations which are positioned in a 
spaced relationship from the exterior outer surface and with the viewing 
means positioned within the housing, all forming a liquid tight seal with 
the housing. 
An imaging means for an instrument is disclosed. The imaging means includes 
means defining an image channel within the instrument. The imaging means 
also includes means for defining a rod-like image transferring means 
having a distal end and a proximal end for transmitting an optical image 
within the instrument. The rod-like image transferring means is located 
within the image channel such that the distal end of the rod-like image 
transferring means is located at one end of the instrument and the 
proximal end of the rod-like image transferring means is located at an 
opposed second end of the instrument. The image means also includes means 
for defining at one end of the instrument an objective lens which is 
spaced from the distal end of the rod-like image transferring means for 
focusing an optical image onto an orifice of the rod-like image 
transferring means at the distal end thereof. The image means further 
includes means for rigidly attaching the rod-like image transferring means 
at a selected location along its length and for slidably supporting the 
rod-like image transferring means at least at one location along its 
length. 
The rigid endoscopes known in the prior art, such as the endoscope 
described in U.S. Pat. No. 4,986,258 have certain disadvantages. The 
structure of the elongated shaft is such that the transitional zones which 
define the joint or joints between stages result in reduced mechanical 
stiffness at the joints. The joints or transition zones of the prior art 
endoscope are generally located equidistantly along the elongated shaft. 
The joints appear to provide discrete stress points which during 
deflection and rotation which occurs during the maneuvering of the 
endoscope during a procedure, could result in the elongated shaft becoming 
bent or actually breaking away during the procedure. 
Also, endoscopes and ureteroscopes known in the art have two distinct 
sections in terms of a distal section and a proximal section, and these 
distinct sections are joined together mechanically at a central joint such 
that the transition zone is located centrally along the shaft. The central 
joint or central transition zone is typically a weak or stress point such 
that under flexing or rotational forces, a bending or breaking away or 
separating of the distal section from the proximal section could occur 
during a procedure. 
One advantage of the present invention is that the single transition zone 
between the sheath tube is, in the preferred embodiment, tapered as 
opposed to being stepped. This feature substantially reduces stress 
concentrations which in turn, increases the durability of the shaft to 
bending metal fatigue. 
Another advantage of the present invention is that the ureteroscope has an 
integrated elongated shaft which is formed from two coaxially aligned 
elongated sheath tubes wherein the first elongated sheath tube has a 
selected length as measured from its proximal end to its distal end. The 
second elongated sheath tube is shorter in length than the selected length 
of the first elongated sheath tube. The length of the second semi-rigid 
elongated sheath tube is greater than one-half the length of the first 
elongated sheath tube and less than the selected length. This results in 
defining a transitional zone that is the area, section, location or point 
where the second elongated semi-rigid sheath tube encloses, is contiguous 
to and supports the first elongated sheath tube. As such, the deflectable 
section extends, on one hand, a sufficient distance beyond the distal end 
of the second semi-rigid elongated sheath tube to provide the desired 
flexibility, and, on the other hand, the second semi-rigid sheath tube 
provides sufficient rigidity throughout the length of the elongated shaft 
to inhibit permanent bending or separation. 
Another advantage of the present invention is that the first elongated 
sheath tube includes a deflectable distal section which extends beyond the 
second semi-rigid elongated sheath tube and wherein the distal portion has 
a geometrically shaped cross-sectional area having at least one 
protuberance. By controlling the structure of the geometrically shaped 
cross-sectional area to be essentially non-circular, the flexibility of 
the distal section can be fabricated to essentially have an easy flexing 
direction and a more rigid flexing direction. For example, the geometrical 
shape of the distal section may be triangular shaped, tear drop shaped 
(e.g. two sides of a triangle being straight sides with the third side 
being a sector of a circle) or elliptical shaped having a major and minor 
axis. 
Another advantage of the present invention is that the distal section, in 
the preferred embodiment, terminates at a distal tip having a 
substantially triangular cross-sectional area including a smooth 
triangular shaped perimeter. A triangular shape provides the smallest 
perimeter around the various working and optical channels and thereby 
causes the least dilation of the ureter as the distal section of the 
ureteroscope gently passes through the ureter. In the preferred 
embodiment, the endoscope includes two working channels which preferably 
includes a 3.4 French channel and a 2.3 French channel. Each of the 
working channels can be utilized in the ureteroscopy procedure. 
Another advantage of the present invention is that the distal tip can be 
beveled and has a perimeter, in the preferred embodiment, in the order of 
about 7 French. A 7 French distal tip enables the surgeon to ease the 
distal tip into the urethral orifice with little or no dilation. 
Another advantage of the present invention is that the endoscope when used 
in a ureteroscopy procedure, reduces operating time and patient trauma. 
Certain endoscopic procedures can be performed with no dilation or without 
the use of general anesthesia due to the fact that the small distal tip 
can be easily inserted through the urethral orifice without significant 
patient trauma. 
Another advantage of the present invention is that the endoscope can be 
utilized in a procedure or method for performing a procedure in a cavity 
or passageway in a human body. The method would generally include the step 
of providing an endoscope including an elongated shaft having a first 
elongated sheath tube and a second semi-rigid elongated sheath tube, 
inserting the substantially triangular shaped flexible distal section of 
the elongated shaft into the cavity such as for example, the urethral 
orifice, followed by the second semi-rigid elongated sheath tube which 
passes into the cavity or passageway and viewing from the proximal section 
of the first elongated sheath tube the cavity or passageway through one 
channel in the endoscope. The endoscope disclosed herein includes a first 
working channel and a second working channel and the method further 
comprises the step of passing a working tool through at least one of the 
first working channel or second working channel to perform a procedure in 
a cavity or passageway. 
Another advantage of the present invention is that the endoscope includes 
means defining a fiber optic image bundle channel which encloses and 
receives a fiber optic image bundle. A fiber optic light carrying means or 
bundle is likewise located within the endoscope and is interspersed around 
the working channels and the fiber optic image bundle channel to provide a 
means for carrying light to the distal tip of the endoscope. 
Another advantage of the present invention is that an optical wedge can be 
located at the distal tip of the deflectable section to provide a 
direction of view for the endoscope of about 5 degrees to about 10 degrees 
when viewed under water. 
Another advantage of the present invention is that the interior walls 
forming the first working channel and the second working channel can be 
coated with a material having a reduced coefficient of friction to 
facilitate easy passage of and use of accessories in the working channel. 
Another advantage of the present invention is that an imaging means for an 
instrument is disclosed wherein a rod-like image transferring means, such 
as for example, a fiber optic image bundle channel which contains a fused 
fiber optic image bundle which is utilized for transmitting an optical 
image. The distal end and the proximal end of the rod-like image 
transferring means, e.g. a fused fiber optic bundle, can be supported by a 
first supporting means and a second supporting means, respectably. 
Depending on the structure of the endoscope, the distal end of the 
rod-like image transferring means, such as the fused fiber optic image 
bundle, can be rigidly attached to the first supporting means which spaces 
the face of the fused fiber optic image bundle a predetermined distance 
from the objective lens to enable an image to be focused onto the face of 
the distal end of the fused fiber optic image bundle. The second 
supporting means then permits relative movement between the fused fiber 
optic image bundle and the instrument. This movement, that is the sliding 
relationship between the fused fiber optic image bundle and the second 
supporting means, permits the fused fiber optic image bundle to expand, 
twist or move during deflection and usage of the endoscope and permits 
relative movement to occur without damaging or otherwise breaking the 
fused fiber optic image bundle. Such a supporting means would not be 
required if a flexible, centrally etched fiber optic image transmitting 
bundle were used. 
Another advantage of the present invention is that a fused fiber optic 
image bundle can be rigidly attached at its proximal end to the second 
supporting means and slidably supported at its distal end by a first 
supporting means which permits relative movement between the fused fiber 
optic image bundle and the instrument to occur at the distal end of the 
fused fiber optic image bundle. In this structure, an adjusting means is 
provided for applying an axial translational force to the fused fiber 
optic image bundle to move the entire bundle in a selected direction so as 
to focus the image from an objective lens located at the distal end of the 
instrument onto the face of the fused fiber optic bundle so that a 
viewable image can be viewed through the proximal end of the fused fiber 
optic image bundle. 
Another advantage of the present invention is that an adjustable ocular 
power correcting lens or other similar means can be utilized to provide a 
means for focusing the viewable optical image by the user for diopter 
correction at the proximal end of the endoscope. 
Another advantage of the present invention is that a method for casting a 
housing around an endoscope frame is shown. In the preferred embodiment, 
the method includes the step of assembling an endoscope frame such that 
the working channels, the fused fiber optic image bundle channel and the 
fiber optic light carrying means are positioned in a pre-determined 
arrangement, all of which continue beyond the proximal end of the 
elongated shaft. Each of the above elements are located to extend from the 
housing at preselected locations relative to a predetermined exterior 
outer surface of the housing cast around the endoscope frame and elements 
forming a liquid tight seal therebetween. The input opening means or port 
of the working channels and the light connecting means or light post for 
the fiber optic light carrying means extends a preselected distance beyond 
the exterior surface of the housing so the same are accessible to a user. 
Another advantage of the present invention is that the method for casting a 
housing around the endoscope frame includes the step of forming a mold 
having a cavity of a predetermined shape which defines the predetermined 
exterior outer surface and shape of the housing and defines the openings 
within the housing for passing the input opening means for the working 
channels, the light connecting means or light post for the fiber optic 
light carrying means to extend through the housing and a viewing means 
within a viewing opening for the user to view a viewable image from the 
fiber optic image bundle.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
FIGS. 1-9 and FIG. 12 illustrate an endoscope for practicing this 
invention. The preferred embodiment of the endoscope illustrated in FIGS. 
1-9 and FIG. 12 is as a mini-rigid ureteroscope. The mini-rigid 
ureteroscope permits direct visualization of the ureter for diagnostic, 
therapeutic and endoscopic applications. In performing such procedures, 
the geometrical dimension of the ureteroscope and the flexibility of the 
distal end are important factors to the urologist utilizing the same. 
Typically, the size of the instrument, including its distal tip, is 
measured in the units referred to as "French". For purposes of this 
application, the following formula is utilized to designate the 
geometrical dimension in the French units: 
(1)Profile of tip in millimeters (around the periphery of instrument) / 
.pi.=Equivalent diameter 
(2) Equivalent diameter.times.3=French (unit) 
For example, if the instrument has a circular cross-sectional circumference 
or perimeter of about 3.14 millimeters, the equivalent diameter would be 
about 1 millimeter. Thus, multiplying the equivalent diameter of 1 
millimeter times a factor of 3, the size of the instrument would be equal 
to 3 French. 
In the present application, the French units are utilized to describe the 
size of the shaft and working channels, it being understood that the 
measurement is made as a function of the periphery of the device defined 
in French units using the above formula. Thus, whether the cross-sectional 
area of an elongated sheath tube is circular, a non-circular, such as 
triangular shaped, tear drop shaped, elliptical shaped or other 
geometrical shape, by utilizing the above formula, the size can be 
converted to a standard French unit for comparison purposes. 
It is known to a person skilled in the art to utilize the French unit as 
the method of measuring the size of the endoscopic instrument. For 
purposes of explanation herein, this terminology is used herein. However, 
by using the French units of measurement, it is not intended to limit the 
scope of the disclosure or invention because of the method of explanation. 
FIGS. 1-9 and FIG. 12 disclose a mini-rigid ureteroscope, shown generally 
as 20. This mini-rigid ureteroscope is only one of many variations of 
endoscopes or instruments that can be fabricated using the teachings of 
the present invention. In the embodiment of FIGS. 1-9 and FIG. 12, the 
endoscope includes an elongated shaft shown generally as 22. The elongated 
shaft includes a first elongated sheath tube, shown generally as 26, which 
includes a deflectable distal section 28 and a blended section 36 which 
extends to the proximal section of the first elongated sheath tube 26. The 
first elongated sheath tube 26 has, at its distal end, a triangular-shaped 
cross-sectional area of a selected geometrical dimension which terminates 
in a distal tip 32. It is envisioned that the distal section would 
terminate in other than a triangular-shaped cross-sectional area. Any 
non-circular cross-sectional area or a geometrically shaped 
cross-sectional area having at least one protuberance can be used. For 
example, the geometrical shape can be tear drop shaped, elliptical shaped, 
rounded rectangular shaped or the like. 
The second semi-rigid elongated sheath tube 34, has a predetermined length 
which is greater than one-half of the selected length and less than the 
selected length. This places the transition zone 38 of the two sheaths 
near the distal tip. The second semi-rigid elongated sheath tube 34 is 
positioned over, encloses and supports the proximal section of the first 
elongated sheath tube 26 with the deflectable distal section 28 extending 
beyond the second semi-rigid elongated sheath tube 34. The second 
elongated sheath tube 34 has a cross-sectional shape sufficient to pass 
the first elongated sheath 26 therethrough. 
As is evident from the FIGS. 1 and 2, specifically, the first elongated 
sheath tube 26 and a second elongated sheath tube 34 are coaxially aligned 
tubes and the proximal section of the first elongated sheath tube 26 
extends at least to the proximal end of the second semi-rigid elongated 
sheath tube 34. In the preferred embodiment, and as discussed further in 
connection with FIG. 14, the proximal end of the first elongated sheath 
tube 26 extends beyond the proximal end of the second semi-rigid elongated 
sheath tube 34. In order to provide redundant fastening, the proximal end 
of the first elongated sheath tube 26 is flared to be embedded within a 
cast housing as described in connection with FIG. 14 hereinbelow. 
FIGS. 1 and 2 also show that the deflectable distal section 26 blends at 
area 36 into an inner section 30 spaced from the distal tip 32. The inner 
section 30 is essentially in the form of a continuation of the first 
elongated sheath tube 26 and has, in the preferred embodiment, a generally 
circular cross-section which blends or tapers from the circular 
cross-section to the triangular cross-section at area 36, and wherein the 
triangular shaped cross-sectional area terminates at the distal tip 32. 
The transition zone between the second semi-rigid elongated sheath tube 
and the deflectable distal section is shown as 38. At the distal end of 
the second semi-rigid elongated sheath tube, the end is tapered 
mechanically by polishing or other known manufacturing procedure. 
The proximal end of the first elongated sheath tube 26 and a second 
semi-rigid elongated sheath 34 is operatively connected to a housing shown 
generally as 40. In the preferred embodiment, the housing 40 comprises a 
cast housing 42 having a predetermined shape and an exterior outer surface 
and which includes openings therein to permit passage of certain of the 
various functional elements as working channels of the endoscope, 
therethrough as will be explained in connection with the description of 
FIG. 14 hereinbelow. The endoscope 20 includes a first working channel, a 
second working channel, a fused fiber optic image bundle channel and a 
fiber optic light carrying means wherein the fiber optic light carrying 
means is generally interspersed around the working channel and fused fiber 
optic image bundle channel, all of which are located within the interior 
of the first elongated sheath tube 26. 
The housing 40 includes means for continuing each of the working channels, 
the fused fiber optic image bundle and the fiber optic light carrying 
means to a location external to the exterior outer surface of the housing 
42. Further, the housing 42 provides a rigid support for the input opening 
means of the working channels and the light connection means for the fiber 
optic light carrying means as described below. 
The first working channel terminates in an input opening means or port 48, 
which is operatively connected to the first working channel which, in the 
preferred embodiment, has a measurement of 3.4 French. The input opening 
means or port 48 is supported by a shoulder member 44 which extends 
laterally from the housing 42. The second working channel terminates in a 
separate input opening means or port 50 and, in the preferred embodiment, 
the second working channel has a measurement of 2.3 French. The input 
opening means or port 50 is supported by a shoulder 46 which extends 
laterally from the housing 42. 
As is illustrated in FIGS. 1-5 and 7, the relationship of the shoulders 44 
and 46 is such that the ports 48 and 50, respectfully, are positioned at 
predetermined relationships to each other and to the housing 42 to enable 
the urologist or user to easily access each of the working channels 
through ports 48 and 50, particularly when the endoscope 22 is positioned 
in a patient. Also, in the preferred embodiment, both parts are located in 
the same side for ease of access. 
The housing 42 includes means for supporting a light post 54 which is a 
light connecting means which is operatively connected to the fiber optic 
light carrying means. The light post 54 is adapted to be operatively 
connected to a fiber optic light carrying means or light guide means 
which, in turn, receive light from a light source. 
The housing 42 includes viewing means for supporting a lens system, shown 
generally a 60, and an adjustable ocular lens system 62 for diopter 
correction to permit a surgeon to view the optical image which is 
transmitted axially along the endoscope. The fiber optic image bundle 
terminates in a lens system which transmits a viewable image to the 
objective lens. This is described in greater detail in connection with 
FIGS. 5, 10 and 11. 
In addition, the housing 42 includes indented, formed support surface 64 
which is formed into the housing 42 to permit the urologist or user to 
grasp and support the mini-rigid ureteroscope 22 in order to advance, 
rotate and maneuver the same with a firm positive grasping relationship 
between the instrument and the hand of the user. 
In use, the distal section 28 has a size of about 7 French which allows the 
endoscope to be passed into the undilated ureter of a patient. The two 
working channels, having ports 48 and 50, permit simultaneous irrigation 
and passage of working instrument, accessories and the like. In the 
preferred embodiment, the mini-rigid ureteroscope 20 can have two working 
lengths such as, for example, a 33 centimeter length and a 41 centimeter 
length. The shorter length may be used for distal ureteroscopy and the 
longer unit may be used in the proximal ureter and renal pelvis. 
The two accessory ports 48 and 50 are selected to have a sufficient size to 
permit passage of accessories having a size of approximately 3 French 
which could be utilized in the 3.4 French working channel and accessories 
having a size of approximately 2 French would permit passage of 
accessories having a size of approximately 2.3 French. As is explained in 
the connection with the description of FIG. 5, the interior walls of each 
channel can be coated with a material which has a slippery characteristic 
or low coefficient of friction such that the accessories can be easily 
transported within the channel. As such, a procedure can be performed with 
a minimum of sliding friction existing between the accessories and the 
interior of the working channels. Accessories which could be utilized in 
the working channel include, without limitation, flexible accessories such 
as stone baskets, retrievers, forceps, electrohydraulic lithotriptor 
probes and laser fibers. Also, the channel may be used for irrigation and 
suction. 
In the preferred embodiment, and as further discussed in connection with 
FIGS. 10, 11 and 13 hereof, an optical wedge can be utilized in 
conjunction with the objective lens at the distal tip of the first 
elongated sheath tube 26 to provide an angle of view. In the preferred 
embodiment, the view can be about 5 degrees to about 10 degrees. By 
selecting an appropriate angle of view, the urologist can quickly 
visualize the accessory device as it exits the distal tip of the working 
channel. Of course, the angle of view could vary as to the type of media. 
For example, the effect of the optical wedge would be that if the 
direction of view in water is about 5 degrees, then the direction of view 
in air would be about 14 degrees. The reason for this difference is 
directly a function of the index of refraction of the medium in which the 
optical image is being viewed. 
In the preferred embodiment as illustrated in FIGS. 1-9, the following 
endoscope specification ranges would apply: 
ENDOSCOPE SPECIFICATION RANGES 
1. Shaft diameter: 
Tip=6 Fr-8 Fr for 1 cm-7 cm 
Middle=8 Fr-9 Fr for 5 cm-10 cm 
Proximal=9 Fr-11 Fr 
2. Working channel: 2 Fr-3 Fr (positioned on outside) 
3. Working channel: 3 Fr-4 Fr (positioned on inside) 
4. Working length: 30 cm-45 cm 
5. Overall length: 40 cm-60 cm 
6. Direction of view: 0.degree.-10.degree. 
7. Field of view: 60.degree.-85.degree. 
8. Depth of field: 2-40 mm 
9. Diopter correction: preferred 
With respect to use of the endoscope as a mini-rigid ureteroscope as 
described hereinbefore, the following are two examples of specific 
mini-rigid ureteroscopes utilizing the teachings of the preferred 
embodiment of the invention as described herein: 
______________________________________ 
EXAMPLE I EXAMPLE II 
______________________________________ 
Sheath length/diameter 
(measured from the distal 
end) 
Distal: 4.5 cm/6.9 Fr 
4.5 cm/6.9 Fr 
Middle: 5.5 cm/8.3 Fr 
5.5 cm/8.3 Fr 
Proximal: 23 cm/10.2 Fr 
31 cm/10.2 Fr 
Total working length: 
33 cm (13.0") 
41 cm/(16.2") 
Overall length: 
49 cm (19.3") 
57 cm (22.4") 
Weight: 5.6 ounces 5.7 ounces 
Working Channels (2): 
3.4 Fr and 2.3 Fr 
3.4 Fr and 2.3 Fr 
Field of view: 70.degree. 70.degree. 
Angle of view: 5.degree. 5.degree. 
Depth of focus: 
2-40 mm 2-40 mm 
______________________________________ 
In order to measure the deflection of the deflectable distal end, the 
following tests were conducted on the mini-rigid ureteroscopes of Example 
I and II. 
The housing 42 of the mini-rigid ureteroscope was clamped on a clamping 
surface with the 3.4 French working channel positioned vertically placing 
the base of the triangular shaped distal end essentially horizontal to the 
clamping surface. A downward force of 295 grams was applied 1/4 inch in 
from the distal tip. The following deflections were measured at the distal 
tip: 
______________________________________ 
EXAMPLE I 
EXAMPLE II 
______________________________________ 
Deflections at end of 
4.3 cm 7.9 cm 
shaft (295 grams) 
______________________________________ 
FIGS. 10 and 11 depict pictorially two different lens systems that may be 
utilized using a rod-like image transferring means such as, for example, 
fused fiber optic image bundle for producing a viewable image at the 
proximal end of the endoscope or instrument. 
In FIGS. 10, the fused fiber optic image bundle 72, which in the preferred 
embodiment, is a coherent, cane-like fused fiber optic image bundle having 
a plurality of separate fiber optic elements which are joined together, is 
utilized as the fiber optic image bundle. However, it is readily apparent 
to a person skilled in the art that the rod-like image transferring means 
could be a GRIN lens system or the like. The term "rod-like image 
transferring means" is intended to cover the use of a cane-like coherent 
fiber optic image bundle, an etched, coherent fiber optic image bundle 
(wherein each of the fiber optic elements are independent and are movable 
relative to each fiber optic element), a GRIN lens or other similar lens 
system. 
In FIG. 10, the fiber optic image bundle 72 has a distal end 74 and a 
proximal end 76. The distal end 74 is positioned at a predetermined space 
from an objective lens 80 supported by lens support 84. If desired, an 
optical wedge, shown by optical wedge 82 and a support, both being shown 
in dashed lines, can be utilized to direct the field of view to some 
preferred direction in the objective field. In the embodiment of FIG. 10, 
the distal end 74 of the fiber optic image bundle 72 is movable relative 
to the objective lens 80. A first support 86 is slidable connected to the 
distal end 74 to permit relative movement therebetween. The object being 
viewed through the objective lens 84 is shown by arrow 90. 
The proximal end 76 of the fiber optic image bundle 72 is supported by and 
is rigidly affixed to a second support means 92. The support means 92 
includes an aperture stop 99 and an objective lens 97. The proximal end 76 
can be operatively connected to the second support means 92 by means of 
any one of several means, such as for example, the use of an epoxy bond at 
the common surface shown generally as 94. 
The second support means 90 is operatively coupled to a drive member 96 
which is capable of applying an axial translational force to the fused 
fiber optic image bundle 72 so as to move the same in a selected distance, 
i.e. either towards or away from the objective lens 80 such that the image 
of object 90 passed by the objective lens 80 is focused onto the face 106 
of the distal end 74 of the fused fiber optic image bundle 72. 
The second support means 92 includes a field lens or an objective lens 98 
which forms a viewable image from the virtual image transmitted by the 
fiber optic image bundle 72. The focused image from the field lens 98 is 
passed through an adjustable ocular power correction lens 100 which is 
supported in position by a lens support 102. The lens support 102 is 
operatively connected to an adjusting mechanism 104. The adjustment 
mechanism 104 can be adjusted to move the ocular lens 100 axially relative 
to the fiber optic image bundle 72 axis to provide a focusable viewable 
image to a viewer to correct for diopter variations, which focusable image 
(which would occur in the eye) is depicted by arrow 110. 
FIG. 11 shows another embodiment of a fused fiber optic imaging means for 
an instrument. A means defining a fiber optic image bundle channel such 
as, for example, channel 132, supports a fiber optic image bundle 112 
centrally thereof. The means for defining a fiber optic image bundle 112 
has a distal end 114 and a proximal end 116 for transmitting an optical 
image within the instrument. The fused fiber optic image bundle 112 is 
located within the fiber optic image bundle channel 132 such that the 
distal end 114 of the fiber optic image bundle 112 is located at one end 
of the instrument and the proximal end 116 of the fiber optic image bundle 
112 is located at the opposed second end of the instrument. 
In FIG. 11, a means for defining an objective lens 120 at the one end of 
the instrument, the objective lens 120 which is spaced from the distal end 
114 of the fused fiber optic image bundle 112 for focusing an optical 
image into the face 124 of the fused fiber optic image bundle 112 at the 
distal end thereof. An optical wedge 122 and support, shown by dashed 
lines, establish the direction of the field of view. 
A first supporting means at the distal end 114 and shown generally as 126, 
is operatively connected between the fused fiber optic image bundle 
channel 132 and the distal end 114 of the fused fiber optic image bundle 
112 for supporting the distal end 114 of the fused fiber optic image 
bundle 112 within the instrument. In the embodiment of FIG. 11, the first 
supporting means likewise functions as a means for supporting the 
objective lens 120. By utilizing the first supporting means 126 to rigidly 
fix the position of the objective lens 120 at a predetermined distance 
from the face 124 of the distal end 114 of the fused fiber optic image 
bundle 112, objects within the depth of focus of the objective lens 120 
are always focused onto the face 124 of the distal end 114 of the fiber 
optic image bundle 112. 
The proximal end 116 of the fused fiber optic image bundle 112 is supported 
by a second supporting means 130 which is slidably operatively connected 
thereto for permitting the proximal end 116 of the fiber optic image 
bundle 112 to move relative to the instrument. An field lens 134 is 
operatively connected to the distal end 116 of the fiber optic image 
bundle 112. 
The second supporting means 130 includes a cavity which permits the image 
to be passed therethrough and through an aperture stop 136 to an objective 
lens 142 positioned axially along and spaced from the field lens 134. An 
adjustable focus ocular lens 144 is positioned a predetermined distance 
from the objective lens 142 for enabling a viewer to focus the viewable 
optical image received from the objective lens 142. The adjustable ocular 
power correcting lens 144 is supported by a lens support 146 which is 
adjustable by means of an adjusting means 148. The adjusting means is 
operable to move the adjustable focus ocular lens 144 axially relative to 
the axis of the objective lens 142 to enable a viewer to focus, for 
diopter correction, a viewable image which is depicted by arrow 150. 
With respect to the preferred embodiment described in FIGS. 1-9 hereof, the 
lens system illustrated pictorially and discussed in connection with FIG. 
11 and is shown in detail in FIG. 12 is the preferred lens system. 
However, it is envisioned that the lens system of FIG. 10 could likewise 
be used in the preferred embodiment illustrated in FIGS. 1-9. 
FIG. 12 depicts the preferred embodiment of the proximal portion of the 
fused fiber optic imaging means of an endoscope wherein the endoscope 
contains a fiber optic image bundle channel 162 which encloses a fused 
fiber optic image bundle 170. The elongated shaft (which can be of a 
structure as illustrated in connection with FIGS. 1-9), encloses the fiber 
optic image bundle channel and fiber optic image bundle. Of importance is 
that FIG. 12 illustrates the means wherein the fused fiber optic image 
bundle channel 162 passes through and is supported by a support means 164 
in housing 160 through a slidable support slot shown as 166. The fiber 
optic image bundle channel is shown terminating at a proximal end 168. The 
fused fiber optic image bundle 170 is then passed through a support member 
172 which is slidably supported in support means 164. Field lens 174 is 
optically bonded to the proximal end face of the fused fiber optic image 
bundle 170. A proximal objective lens 176 is mounted into housing 178 
which in turn is rigidly affixed to support member 172. A proximally 
located ocular lens (not shown) is used to magnify the image created by 
the proximal objective lens 176 for operator viewing. 
FIG. 13 illustrates pictorially a preferred embodiment for terminating the 
distal end of an endoscope utilized as a mini-rigid ureteroscope. In FIG. 
13, a fiber optic image bundle channel 182 supports a fused fiber optic 
image bundle 186. The first supporting means 190 supports the distal end 
188 of the fused fiber optic image bundle 186. Concurrently, the first 
supporting means 190 supports an objective lens system, shown generally as 
194 which includes an optical wedge 196, in a fixed spaced relationship to 
the distal end 188 of the fused fiber optic image bundle 186. 
The lens system of FIG. 13 can be utilized in a wide variety of endoscopes 
including specifically the mini-rigid ureteroscope depicted by FIGS. 1-9 
and FIG. 12 hereof. 
A mini-rigid ureteroscope utilizing the teachings of the present invention 
has a triangular shaped cross-sectional area of a selected dimension which 
terminates in a distal tip. FIG. 14, illustrates, in an end elevational 
view, the structure of an endoscope which is utilized as a mini-rigid 
ureteroscope depicted in FIGS. 1-9. In FIGS. 1-9, the first elongated 
sheath tube 26 terminates in a triangular shaped cross-sectional member 28 
having a triangular shaped periphery shown by thin walled member 198 which 
defines an outer peripheral surface. The length of the outer peripheral 
surface of thin-walled member 198 is used to calculate the French size of 
the instrument at the distal end as described hereinbefore. The triangular 
shaped distal tip 28 encloses all of the functional working elements which 
are located interiorly to the first elongated sheath tube 26. 
In FIG. 14, the triangular shaped distal end 28, which is defined by the 
thin walled member 198, encloses at lease one working channel and, in the 
preferred embodiment, encloses a first working channel 200 in and a second 
working channel 202. As depicted in FIG. 14, the working channels are of 
different sizes. However, it is also envisioned that an endoscope could 
utilize a first working channel and a second working channel of the same 
size. In the embodiment illustrated in FIG. 14, the larger working channel 
200, has the size of 3.2 French while the second working channel, channel 
202, has a working size of 2.3 French. 
Since working tools, accessories and the like can be utilized in each of 
the working channels 200 and 202, the interior walls of each of the 
working channels can be coated or formed with a coating material depicted 
by surface 204, which has a low coefficient of sliding friction to reduce 
the amount of sliding friction between a working tool or an accessory 
utilized in the channel and the walls defining the working channel. 
In FIG. 14, a fiber optic image channel 206 includes a fiber optic image 
bundle 208. During fabrication of the endoscope, the fiber optic image 
bundle 208 need not be inserted into the fiber optic image bundle channel 
206 until final assembly of the endoscope. This is important in connection 
with the method of casting the housing, which is described hereinafter, 
with respect to FIG. 15. 
In addition, in order to provide sufficient light to the viewing area on 
site located adjacent the distal tip of the instrument in a cavity or 
passageway, a fiber optic light carrying means, such as, for example, the 
fiber optic elements shown generally as 210, are interspersed around the 
first working channel 200, the second working channel 202 and the fiber 
optic image bundle channel 206. If an optical wedge is utilized, such as 
for example, optical wedge depicted as 196 in FIG. 13, the optical wedge 
would be positioned an axial alignment with the face o the fiber optic 
image bundle 208 illustrated in FIG. 14 and oriented so that the viewing 
angle is directed towards the working channels. 
FIG. 15 illustrates pictorially a method for casting a housing around an 
endoscope frame. In FIG. 15, the elongated shaft, shown generally as 220, 
includes a first elongated sheath tube 222 having a proximal end which 
terminates in a flared end 232. A second semi-rigid elongated sheath tube 
224 has its proximal end 226 which terminates a predetermined distance 
before the flared end 232 at the first elongated sheath tube 222. The 
generally circular shaped proximal end 226 has a generally cross-sectional 
area which is of a sufficient geometrical dimension to permit the proximal 
section of the first elongated shaft 222 to pass therethrough. 
The housing 220 including its endoscope frame 240 is depicted in FIG. 15 
and includes means for continuing a first working channel 244 which 
terminates in an input opening means, or port 250. Port 250 includes a 
serrated bottom support member 256. The input opening means, or port 250 
is operatively connected to the first working channel which, in the 
preferred embodiment, has a size of 3.4 French. The housing 220 includes a 
first shoulder 276 which is adapted to support and position the serrated 
bottom member 256 of the input opening mean or port 250 securely within 
the housing 220. 
In addition, the housing 220 and its endoscope frame 240 includes means for 
continuing a second working channel 246 which terminates in an input 
opening means or port 260. In the preferred embodiment, the second working 
channel, which terminates in port 260, having a size of 2.3 French. Input 
opening means or port 260 includes a serrated support bottom member 266 
which is positioned in and is supported by a shoulder 274 which is part of 
and is defined by the housing 220. The ports 250 and 260 are positioned in 
a relationship to each other end to extend in a selected direction from 
the housing 220 so as to permit a urologist or user to have access to each 
of the working channels. The ports 250 and 260 could be located in other 
positions around the housing, for example, one on each side of the 
housing. 
In addition, the interior portion of the housing 220 encloses the endoscope 
frame 240 which is adapted to form a part of the structure of the housing 
220 and include a bulkhead means 242 for supporting a viewing means which 
is adapted to cooperate with a fused fiber optic image bundle which is 
ultimately to be located into the fiber optic image bundle channel as 
shown in FIG. 14. In the housing illustrated in FIG. 15, the fused fiber 
optic image bundle assembly has not been installed into the assembly. 
In addition, a fiber optic light carrying means 278 extends from the 
proximal end of the endoscope through the flared end 232 of the first 
elongated sheath tube 222 and extends up to a light input connecting means 
or light post 284. The housing 220 further includes means for defining an 
opening or aperture 282 which is in coaxial alignment With the bulkhead 
means 242. The aperture 282 is used in the preferred embodiment to receive 
and support an ocular lens as shown in element 62 in FIGS. 1-9. 
In order to fabricate the housing and assembly described in FIG. 15, a 
unique and novel method for casting housing around an endoscope frame is 
utilized in fabricating the preferred embodiment of the invention. The 
method for casting a housing around an endoscope frame comprises 
assembling an endoscope frame 240 which includes the proximal end of an 
elongated shaft and specifically includes the flared end 232 of the first 
elongated sheath tube 222. In the embodiment of FIG. 15, the elongated 
shaft includes a first working channel, a second working channel and a 
fiber optic light carrying means which are continued with the housing 220. 
In FIG. 15, the continuation of the first working channel is shown as 
element 244, the second working channel is shown by element 246 and, the 
fiber optic image bundle channel 290 is adapted to cooperate with a 
bulkhead means 242. The fiber optic light carrying means is depicted by 
element 278 and terminates in the light input means or light post 284. As 
such, each of the working channels and the fiber optic light carrying 
means terminations extend in separate and distinct predetermined 
directions from the elongated shaft to a preselected location through the 
housing 220 and then extend beyond the exterior outer surface of housing 
220. Each of the working channels are terminated in an input opening 
means, namely input opening means 250 and 260 which extend beyond the 
housing 220. The fiber optic image bundle cooperates with a bulkhead means 
242 which is interior to the housing 220 and in central opening 282. 
When the endoscope frame has been assembled, as described above, the next 
step comprises casting with a curable material a housing wherein the 
housing is formed around the endoscope frame and has a predetermined shape 
and an exterior outer surface. As such, the casting material encloses and 
surrounds the proximal end of the elongated shaft, including the flared 
end 232, encloses the means continuing the first working channel 244 and 
the second working channel 246, the fiber optic image bundle channel 290 
and the fiber optic light carrying means 278 such that the input opening 
means 250 and 260 of each of the working channels 244 and 246, 
respectively, extend through the exterior outer surface of the housing 220 
at separate and distinct locations while being located in a special 
relationship from the exterior outer surface. The bulkhead means 242 is 
positioned centrally within the housing within the interior of the opening 
282. The housing 220 forms a light tight fluid seal between the housing 
and each of the above described elements. 
In connection with the above method, as described hereinbefore, the 
elongated shaft, namely the first elongated sheath tube 222, has an outer 
surface which engages the rear section 292 of the housing 220. During the 
step of casting, the casting would include the step of enclosing the 
flared end 232 of the elongated shaft 218 in a casting material defining 
the rear section 292 of housing 220 to form a redundant fastening of the 
elongated shaft 218 to the cast housing 220. The redundant fastening 
comprises a mechanical interface between the flared end 232 of the 
elongated shaft 218 and a cast housing 220 while a second fastening occurs 
through the gripping action between the outer surface of the proximal 
section of the elongated shaft, namely proximal end of the first elongated 
sheath tube 222 operatively connected to the flared end 232 and the 
proximal section of the second semi-rigid elongated sheath tube 224 
including proximal end 226 and the rear section 292 of the housing. 
The shape and exterior outer surface of the housing 220 including its rear 
section 292 is formed from a mold having a cavity which defines the 
predetermined shape and exterior outer surface. The mold includes openings 
to support the input opening means of each of the working channels and the 
light connecting means, or light post, of the fiber optic light carrying 
means. 
The next step of the method utilizing the mold would be positioning the 
mold around the endoscope frame 240. After the endoscope frame 240 is in 
place and the other functional elements are in the proper openings in the 
mold, the mold is then filled with a curable casting material. The cast 
material can be any well known casting material such as for example a two 
part polyurethane material system which includes a polyurethane resin and 
appropriate hardener. During the curing of the casting material in the 
mold in the presence of the endoscope frame, the assembly may be placed, 
during the curing process, into a baking oven. It is important that, 
during the curing process, the overall temperature of the assembly of the 
mold, casting material and endoscope frame and the functional components 
do not exceed a temperature which would affect the mechanical 
characteristics of the working channels, the fiber optic image bundle 
channel and the fiber optic light carrying means. If a curing material is 
utilized which produces an exothermic reaction, and the same occurs at 
room temperature or in the alternative the curing takes place in a 
controlled atmosphere, such as, for example, a baking oven at 80.degree. 
C. (176.degree. F.), the curing temperature and/or baking temperature must 
be limited to a temperature would not affect the mechanical 
characteristics of the functional elements as described above. 
It is envisioned that any type of casting material could be utilized, such 
as a curable polymer plastic, polyurethane material or any other material 
which could by utilized for an acceptable housing for an endoscope or for 
a mini-rigid ureteroscope. 
When the curing process is completed, the next step would be removing of 
the mold when the casting material is cured. 
FIG. 16 depicts yet another embodiment utilizing the teachings of this 
invention for a rigid endoscope 300. A housing 302 supports a first 
elongated sheath tube 304 which is enclosed by a second semi-rigid 
elongated sheath tube 306. A fused fiber optic image bundle 308 would 
extend centrally through the elongated shaft 310 defined by the first 
elongated sheath tube 304 and the second semi-rigid elongated sheath tube 
306. 
The fused fiber optic image bundle 308 would terminate at a proximal end 
316 in a support member shown generally as 314 which would be in the form 
of a slidable supporting means for the proximal end 316 within the housing 
302. A lens support 317 cooperates with a spring means 318 to permit 
relative movement between the fused fiber optic image bundle 308 and the 
housing 302. The optical image which would be located at the proximal end 
316 of the fused fiber optic image bundle 308 which is viewed through 
ocular lens system 322. A window 330 is provided in the eyepiece 336. A 
fiber optic light carrying bundle, shown generally as 342, would extend 
from the distal end of the endoscope, interspersed between the first 
elongated sheath tube 304 and the second elongated sheath tube 306 and 
into a light post structure 340 having a support boss 344 for providing a 
connecting means between a light guide and a light source. 
The teachings set forth herein are directed in the preferred embodiment to 
medical applications. However, the teachings hereof could be used in other 
applications, such as, for example, borescopes, industrial systems, 
nuclear systems and the like. All such applications are envisioned to be 
encompassed by the apparatus and methods disclosed and claimed herein.