U.S. patent number 3,610,231 [Application Number 04/745,472] was granted by the patent office on 1971-10-05 for endoscope.
This patent grant is currently assigned to Olympus Optical Company, Ltd.. Invention is credited to Teruo Ouchi, Nagashige Takahashi.
United States Patent |
3,610,231 |
Takahashi , et al. |
October 5, 1971 |
ENDOSCOPE
Abstract
An endoscope especially adapted to inspect the bronchi of a
human body or the like and having a forward end portion and a
control housing connected to the forward end portion through an
elongated flexible tube. The forward end portion can be flexed by
the control from the control housing so that it can be smoothly
inserted into the bronchi. The endoscope is provided with an
observation optical system, an illuminating optical system and a
control mechanism for flexing the forward end portion together with
a pharmaceutical liquid injecting tube, a forceps conducting tube
and a suction tube for sucking unwanted matter in the bronchi
therefrom all in combination in compact form in the forward end
portion without increasing the outer diameter of the forward end
portion. To ensure positive and exact flexing of the forward end
portion, a stay means made of a resilient, relatively stiff wire is
provided longitudinally adjacent to the inner wall of the flexible
tube section of the forward end portion. The both ends of the stay
means are fixedly secured to the inner wall of the flexible tube
section at its forward and rearward ends so that the stay means
serves as a backbone to prevent the flexible tube section from
being unduly contracted as a whole while the flexibility of the
flexible tube section is maintained. To effect the bending of the
flexible tube section, string means extend from the control
mechanism through the elongated tube, the forward ends of the
string means are secured to the inner wall of the flexible tube
section so that the flexible tube section can be flexed by pulling
the string means by the operation of the control mechanism.
Inventors: |
Takahashi; Nagashige (Tokyo,
JA), Ouchi; Teruo (Tokyo, JA) |
Assignee: |
Olympus Optical Company, Ltd.
(Tokyo, JA)
|
Family
ID: |
26403715 |
Appl.
No.: |
04/745,472 |
Filed: |
July 17, 1968 |
Foreign Application Priority Data
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|
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Jul 21, 1967 [JA] |
|
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62666/67 |
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Current U.S.
Class: |
600/139; 385/119;
396/17; 600/146; 385/118 |
Current CPC
Class: |
A61B
1/0052 (20130101); A61B 1/0057 (20130101); A61B
1/2676 (20130101); A61B 1/00165 (20130101); A61B
1/07 (20130101) |
Current International
Class: |
A61B
1/267 (20060101); A61B 1/005 (20060101); A61b
001/06 () |
Field of
Search: |
;128/4,5,6,7,9,2
;95/11,11.5 ;138/120 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
|
|
|
|
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880,639 |
|
Oct 1961 |
|
GB |
|
4,699 |
|
Sep 1905 |
|
FR |
|
Primary Examiner: Gaudet; Richard A.
Assistant Examiner: Dunne; G. F.
Claims
We claim:
1. An improved control mechanism for use in an endoscope which
includes a control housing, an elongated flexible tube extending
from said housing, a flexible tubular probe provided at the front
end of said tube an objective lens system in said probe, ocular
means in said housing, means for transmitting an image from said
objective lens system through said tube to said ocular means, a
combined forceps conducting and suction tube extending from said
housing through said tube to said probe, a medication injecting
tube extending from the housing through said tube to the probe, and
illuminating means provided at the probe, said improved control
mechanism comprising a single resiliently bendable but
noncontractable stay extending longitudinally along only one side
of said tubular probe, said stay having a front end secured to the
front end of the probe and a rear end secured to said tube at the
rear end of the probe so that the stay permits lateral bending of
the probe in all radial planes but prevents longitudinal
contraction thereof as a whole, and control means provided in said
housing and including at least two strings passing through said
flexible tube into said probe, the front ends of said strings being
secured to the front end of the probe at points which are spaced
from the front end of said stay in such manner that the probe may
be bent laterally in at least two different radial planes by
pulling of the respective strings. 2The device as defined in claim
1 which is further characterized in that said stay comprises a
length of resiliently flexible
wire. 3. The device as defined in claim 1 wherein said control
means also includes a third string passing through said flexible
tube into said probe and having its front end secured t the front
end of the probe at a point spaced from the front ends of the
first-mentioned strings and of said
stay. 4. The device as defined in claim 1 together with at least
two flexible but noncontractable pipes secured in said housing and
passing through said flexible tube, said strings passing slidably
through the respective pipes, the front end of one of the pipes
being secured at the rear end of said probe and the front end of
the other pipe being secured intermediate the ends of the probe,
whereby the probe may be laterally bent to different radii
selectively along its whole length or along the length of its front
end portion by selective actuation of said strings.
Description
BACKGROUND OF THE INVENTION
The present invention relates to a novel and useful endoscope
particularly adapted to be used for the inspection of the bronchi
of a human body or the like having very narrow and tortuous paths
having different radii of curvature.
The present invention also relates to a novel and useful flexible
tube assembly adapted to be incorporated in the forward end portion
of the endoscope of the type described above which is to be
inserted into he bronchi smoothly without injuring the inner wall
of the bronchi.
It is well known that the diameters of the forward end portion and
the elongated flexible tube of an endoscope for the inspection of
the bronchi of a human body or the like must be very small such as
the diameter of 5.0 mm. or 5.5 mm. for the inspection of the deeper
portion in the bronchi in comparison with commonly used endoscopes
provided with the forward end portion having the diameter of
about12 mm. for the inspection of the gullet or the stomach or the
like.
On the other hand, it is desirable for an endoscope for the
inspection of the bronchi to incorporate therein not only an
observation optical system such s an objective lens system and a
fiber optical system but also an illuminating optical system for
illuminating the object to be inspected, a pharmaceutical liquid
injection tube for injecting a pharmaceutical liquid such as an
anesthetic into the bronchi, a forceps conducting tube for
inserting the forceps into the bronchi so as to collect the sample
tissues to be inspected during the observation of the object, a
suction tube for sucking unwanted matter such as phlegm out of the
bronchi, and string means for adjustably flexing the forward end
portion of the endoscope in desired direction.
However, because of the very limited diameter of the forward end
portion of the endoscope for the inspection of the bronchi, it has
been impossible to incorporate all or most of the above-described
various elements compactly in the forward end portion of the
endoscope while the operation of each of the elements is kept
satisfactory.
The reasons for the above facts are as follows. The suction tube
for sucking the unwanted matter such as phlegm form the bronchi
cannot be made too small because the phlegm has a certain viscosity
making it difficult to smoothly suck the phlegm through the tube.
If the wall thickness of the suction tube is made too thin in order
to increase the inner diameter of the tube, then the tube tends to
be easily collapsed in the region of the forward end portion of the
endoscope when it is bent for the smooth insertion thereof into the
bronchi thereby causing the tube to be blocked.
Further, the mechanism for effecting the bending of the forward end
portion of the endoscope requires relatively greater space thereby
preventing the mechanism from being compactly incorporated in the
forward end portion having a very limited diameter.
The present invention aims at avoiding the above disadvantages of
the prior art and providing a novel and useful endoscope especially
for inspecting the bronchi of a human body or the like and a novel
and useful flexible tube assembly to be incorporated in the forward
end portion of the endoscope.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a novel and useful
endoscope for the inspection of the bronchi of a human body or the
like which avoids the above-described disadvantages of the prior
art endoscope.
Another object of the present invention is to provide a novel and
useful endoscope of the type described above in which an
observation optical system, an illuminating optical system and a
mechanism including string means for effecting the bending of the
forward end portion of the endoscope for facilitating the smooth
insertion thereof into the bronchi are compactly incorporated in
the forward end portion of the endoscope having a very limited
diameter such as 5.0 mm. or 5.5 mm. together with a pharmaceutical
liquid injection tube, a forceps conducting tube and a suction tube
for sucking unwanted matter such as phlegm form the bronchi into
the which the forward end portion of the endoscope is inserted.
In order to smoothly insert the forward end portion of the
endoscope into the bronchi, it is desired to permit the forward end
portion of the endoscope to be bent not only in any desired
direction but also to different radii of curvature so as to conform
the flexure of the forward end portion with different curvatures of
the bronchi.
This is accomplished by the significant feature of the present
invention.
Therefore, further object of the present invention is to provide a
novel and useful flexible tube assembly particularly adapted to be
incorporated in the forward end portion of an endoscope which can
be bent not only in any desired direction but also to different
radii of curvature of the flexure of the forward end portion of the
endoscope so as to facilitate the smooth insertion thereof into the
bronchi having narrow and tortuous paths of different
curvatures.
In principle, the forward end portion of the endoscope constructed
in accordance with the present invention comprises a flexible tube
section such as a coarsely helically coiled strip forming a tube
and two or more string means with the forward ends thereof being
secured to the forward end of the flexible tube section and with
the rearward ends thereof extending through the flexible tube
section and being secured to a control mechanism in a control
housing of the endoscope connected to the forward end portion
through an elongated flexible tube through which the string means
extend so that the flexible tube section can be bent in any desired
direction by pulling the selected one or more of the string means
by the selective operation of the control mechanism.
According to an important feature of the present invention, a stay
means is provided in the flexible tube section which is of a
resilient, relatively stiff nature and extends longitudinally in
the the flexible tube section adjacent to the inner wall thereof
with the respective ends of the stay means being secured to the
forward and rearward ends of the flexible tube section,
respectively, so that the stay means serves as a backbone of the
flexible tube section to prevent the flexible tube section from
being unduly contracted as a whole by the actuation of the string
means while the flexibility of the flexible tube section is
maintained. Thus, the flexible tube section can be bent in any
desired direction by selectively pulling one or more of the string
means by different amounts by means of the control mechanism.
In accordance with a further important feature of the present
invention, a noncontractable pipe such as a tightly coiled wire
forming a pipe is slidably fitted on each of the string means with
the rearward end of each of the noncontractable pipes being fixed
to stationary points in the control housing while the forward ends
thereof terminate in the region of the flexible tube section and
are secured to the inner wall thereof so that the movement of each
of the string means relative to the noncontractable pipe slidably
fitted thereon at the rearward end thereof as given by the
operation of the control mechanism is exactly transmitted to the
forward end portion of the string means relative to the forward end
of the noncontractable pipes, thereby permitting the flexible tube
section to be flexed exactly as determined by the operation of the
control mechanism
In accordance with a still further important feature of the present
invention, only a pair of string means each having a
noncontractable pipe slidably fitted thereon are provided together
with a stay means in like manner as described above, each of the
string means being arranged at opposite sides of the stay means in
substantially symmetrical relationship to each other in cross
section of the flexible tube section with an angle being formed
between two lines passing the center of the stay means and the
respective string means in cross section of the flexible tube
section, the forward end of one of the noncontractable pipes
terminating at a position intermediate the forward and rearward
ends of the flexible tube section and being secured thereto while
the forward end of the other of the noncontractable pipes
terminates at a position adjacent to the rearward end of the
flexible tube section and is secured thereto so that the distance
between the forward end of the flexible tube section and the
forward end of the one of the noncontractable pipes is made smaller
than the distance between the forward end of the flexible tube
section and the forward end of the one of the noncontractable pipes
is made smaller than the distance between the forward end of the
flexible tube section and the forward end of the other of the
noncontractable pipes. Since the bending of the flexible tube
section is effected in the portion of the flexible tube section
which is contracted by the actuation of the string means with the
stay means serving as a backbone of the flexible tube section, the
above-described construction in which the forward ends of the
noncontractable pipes are secured to the inner wall of the flexible
tube section at positions longitudinally shifted relative to each
other permits the flexible tube section to be bent to different
radius of curvature by selectively actuating either one of the
string means. Further, by actuating both the string means
selectively at different degrees, the flexible tube section can be
bent in any desired direction and to varying radius of curvature
between the range as determined by pulling either one of the string
means only.
Other objects and advantages of the present invention will be clear
by reading the following description of the preferred embodiments
of the present invention with reference to the accompanying
drawings illustrating the preferred embodiments of the present
invention,
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a general side view showing the endoscope constructed in
accordance with one feature of the present invention;
FIG. 2 is a fragmentary side view of the endoscope shown in FIG. 1
as viewed from the right in FIG. 1;
FIG. 3 is a schematic view showing the various elements
incorporated in the endoscope shown in FIG. 1;
FIG. 4 is a schematic view showing the mechanism for effecting the
bending of the forward end portion of the endoscope shown in FIG.
1;
FIG. 5 is a plan view of the forward end plate provided at the
forward end of the forward end portion of the endoscope shown in
FIG. 1 as seen from the rear side thereof;
FIG. 6 is a view showing the manner in which the forward end
portion of the endoscope is bent in different directions by the
selective actuation of the string means incorporated in the
mechanism for effecting the bending of the forward end portion of
the endoscope;
FIG. 7 is a fragmentary view showing the forward end of the forceps
conducting tube around which a helically coiled strip is secured so
as to prevent the forward end of the tube from being collapsed when
the tube is bent;
FIG. 8 is a front end view showing the forward end plate provided
with various elements for the operation of the endoscope;
FIG. 9 is a view showing the manner in which the forward end
portion of the endoscope is inserted into the bronchi of a human
body;
FIG. 10 is a longitudinal sectional view of the forward end portion
of an endoscope constructed in accordance with another feature of
the present invention;
FIG. 11 is a cross-sectional view taken along the line 11--11 in
FIG. 10; and
FIG. 12 is a longitudinal sectional view taken along line 12--12 in
FIG. 10 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Now the present invention will be described in detail with
reference to the drawings.
FIGS. 1 and 2 show an embodiment of the endoscope constructed in
accordance with one feature of the present invention. The endoscope
comprises a control housing 1, an elongated flexible tube 2 and a
forward end portion 3. The control housing 1 is connected to the
rearward end of the elongated flexible tube 2 around which gripping
means 4 is provided for easy handling of the endoscope while the
forward end of the elongated flexible tube 2 is connected to the
forward end portion 3. The forward end portion 3 together with the
elongated flexible tube 2 is adapted to be inserted into the
bronchi of a human body or the like so as to inspect the desired
portion of the bronchi as described hereinbelow. As shown in FIG.
3, an objective lens system 5 is provided in a viewing window of
the forward end portion 3 so that the light from an object to be
inspected is received through the viewing window by the objective
lens system 5 to thereby form an image of the object in the forward
end portion 3. An image transmitting optical system 6 such as a
fiber optical system extends from the forward end portion 3 through
the elongated flexible tube 2 to the control housing 1. The forward
end of the image-transmitting fiber optical system is located in
the forward end portion 3 in opposing relation to the objective
lens system 5 in alignment therewith so that the image of the
object is focused on the forward end of the image-transmitting
optical system 6 thereby permitting the image to be transmitted
through the image transmitting optical system 6 to the rearward end
thereof. An ocular means 7 is provided in the control housing 1
which is located in opposing relation to the rearward end of the
image-transmitting optical system 6 in alignment therewith so that
the image of the object thus transmitting to the rearward end of
the image-transmitting optical system 6 is viewed through the
ocular means 7. An illuminating fiber optical system 8 extends from
the forward end portion 3 through the elongated flexible tube 2 to
the control housing with the forward end thereof being in alignment
with an illuminating window provided in the forward end portion 3
while the rearward end thereof being in alignment with an
illuminating window provided in the forward end portion 3 while the
rearward end thereof terminates in a mounting 8a provided in the
control housing 1. A light source (not shown) may be connected to
the mounting 8a preferably through a further fiber optical system
provided with a mating connecting member (not shown) for the
mounting 88 at the outer end thereof so that, when the light source
is connected to the mounting 8a and energized, the light from the
light source is received by the rearward end of the illuminating
fiber optical system 8 and transmitted therethrough to the forward
end thereof thereby permitting the thus transmitted light to be
emitted from the forward end of the illuminating fiber optical
system 8 through the illuminating window in the forward end portion
3 so as to illuminate the image to be inspected. A forceps
conducting tube 9 and a pharmaceutical liquid injecting tube 10
also extend from the forward end of the forward end portion 3
through the elongated flexible tube 2 to the control housing 1 with
the rearward end of the forceps conducting tube 9 terminating at an
opening 9a provided in the control housing 1 while the rearward end
of the pharmaceutical liquid injecting tube 10 terminates at an
opening 10a also provided in the control housing 1. Thus, the
forceps (not shown) are inserted from the opening 9a into the
forceps conducting tube 9 therethrough so as to be projected from
the forward end of the forward end portion 3 thereby permitting the
forceps to be manipulated from the exterior of the control housing
1 during the observation of the object by means of the observation
optical system in order to collect the sample tissues necessary for
the inspection from the bronchi into which the forward end portion
3 is inserted while the pharmaceutical liquid such as the
anesthetic which is required for the inspection or the surgical
operation of the bronchi can be supplied from a pharmaceutical
liquid supply source (not shown) connected to the opening 10a
through the pharmaceutical liquid injecting tube 10 to the forward
end thereof so that the pharmaceutical liquid is injected into the
bronchi.
The forceps conducting tube 9 is provided with a suction tube 11
branched from the forceps conducting tube 9 in the control housing
1 and terminating at an opening 11a which is provided in control
housing 1. Means for closing the forceps conducting tube 9 such as
a shutter blade 12 is provided in the tube 9 at a position
intermediate the rearward end of the tube 9 and the position at
which the suction tube 11 is branched from the tube 9. A knob 12a
for manually actuating the shutter blade 12 is attached thereto and
projects outwardly from the control housing 1 so that the shutter
blade 12 is opened and closed by the manual operation of the knob
12a. A suction device (not shown) may be connected to the opening
11a when unwanted matter such as phlegm in the bronchi should be
removed from the bronchi into which the forward end portion 3 of
the endoscope is inserted. In this case, the forceps are withdrawn
from the endoscope and the shutter blade 12 is moved to its closed
position by the operation of the knob 12a. Thus, when the suction
device is operated, the unwanted matter such as the phlegm in the
bronchi can be taken out from the bronchi through the forceps
conducting tube 9 and the suction tube 11 by the sucking action of
the suction device connected to the opening 11a.
FIGS. 3 and 4 show one embodiment of the mechanism for controlling
the bending of the forward end portion 3 of the endoscope. The
forward end portion 3 comprises a forward endplate 14, a rearward
end 15 such as an annular ring and a flexible tube section 13 such
as a coarsely helically coiled steel strip forming a tubelike shape
which flexible connected the forward end plate 14 and the rearward
end 15. As shown in FIG. 8, the forward end plate 14 is provided
with the viewing window with which the objective lens system 5 in
the forward end portion 3 is located in alignment, the illuminating
fiber optical system 6 is located in alignment, opening connected
to the forward end of the forceps conducting tube 9 and an opening
connected to the forward end of the pharmaceutical liquid injecting
tube 10. As shown in FIG. 4, a stay means 16 such as a resilient,
relatively stiff wire extends longitudinally along the inner wall
of the flexible tube section 13 adjacent thereto. The forward end
16a of the stay means 16 is connected to the forward end plate 14
while the rearward end 16b of the stay means 16 is fixedly
connected to the forward end of the elongated flexible tube 2
adjacent to the rearward end 15 of the forward end portion 3 so
that the stay means 16 serves as a backbone of the flexible tube
section 13 of the forward end portion 3 to prevent the flexible
tube section 13 from being unduly contracted as a whole when it is
subjected to an external force tending to contract the flexible
tube section 13 while it is allowed to be bent thereby. A pair of
strings 17, 18 extend from the forward end portion 3 through the
elongated flexible tube 2 to the control housing 1. The forward
ends 17a 18a of the strings 17, 18 are connected to the forward end
plate 14 at positions opposite to each other with respect to the
position at which the forward end 16a of the stay means 16 is
connected to the forward end plate 14. Further string 19 extends
from the forward end portion 3 through the elongated tube 2 to the
control housing 1. The forward end 19a of the string 19 is
connected to the forward end plate 14 at a position substantially
diametrically opposite to the position at which the forward end 16a
of the stay means 16 is connected to the forward end plate 14.
A control mechanism comprising two manually rotatable discs 20, 21
having the common axis of rotation 22 is provided in the control
housing 1. Either of the discs 20, 21 may be provided with
projections 20a and/or 21a (only the projection 20a is shown)
respectively, which project from the control housing 1 so as to be
manually actuated selectively so that either or both of the discs
20, 21 are rotated. Alternatively, the outer periphery of each of
the discs 20, 21 is provided with a knurled surface a part of which
projects from the control housing 1 thereby permitting either or
both of the discs 20, 21 to be manually rotated selectively by
means of the knurled surfaces of the discs 20, 21. The rearward
ends 17b 18b of the pair of strings 17, 18 are connected to the
disc 20 at positions diametrically opposite to each other so that
the manual rotation of the disc 20 in one direction causes one of
the strings 17, 18 to be pulled while the other of the strings 17,
18 is loosened and vice versa. The rearward end 19b of the further
string 19 is connected to the disc 21 so that the string 19 is
pulled by the manual rotation of the disc 21 in one direction.
Brake means 23, 24 such as friction pads may be provided for the
discs 20, 21, respectively so that the discs 20, 21 are
frictionally held at their adjusted positions. Noncontractable
pipes 25, 26 and 27 such as tightly coiled wires forming pipes
extend through the elongated flexible tube 2 and are slidably
fitted on the strings 17, 18 and 19, respectively, with the
rearward ends 25a 26a and 27a thereof being fixedly secured to
stationary points in the control housing 1 while the forward ends
of the pipes 25, 26 and 27 terminate at the rearward end 15 of the
forward end portion 3 of the endoscope and secured thereto, so that
the movement of the strings 17, 18 and 19 relative to the
noncontractable pipes 25, 26 and 27, respectively, as given at the
respective rearward ends of the strings 17, 18 and 29 by the
operation of the control mechanism can be exactly transmitted to
the forward ends of the strings 17, 18 and 19 relative to the
respective forward ends of pipes 25, 26 and 17, respectively.
In operation, the forward end portion 3 can be bent toward the
right as viewed in FIGS. 5 and 6 by pulling only the string 19 by
the manual operation of the disc 21 in the direction of the arrow
shown in FIG. 4. Under this condition, when the disc 20 is manually
rotated in the direction shown by the arrow in FIG. 4, the string
17 is pulled while the string 18 is loosened so that the forward
end portion 3 is bent in the direction shown by the arrow a in FIG.
6. When the disc 20 is rotated in the opposite direction, the
forward end portion 3 is bent in the direction, the forward end
portion 3 is bent in the direction shown by the arrow b in FIG.
6.
It is apparent that the pulling of only of the string 17 or 18
causes the forward end portion 3 to be bent further upwardly or
downwardly as viewed in FIG. 6. Therefore, the forward end portion
3 can be bent in any direction within a predetermined solid angle
determined by the flexure of the flexible tube section 13 by
selectively actuating the strings 17, 18 and 19 by means of the
control mechanism. The stay means 16 serves as a backbone to
prevent the flexible section 13 from being unduly contracted as a
whole by the actuation of the strings 17, 18 and 19 while the
flexibility of the forward end portion 3 is maintained.
The brake means 23, 24 frictionally hold the discs 20, 21 in their
adjusted positions, respectively, thereby facilitating the
inspection of the bronchi by the endoscope.
The forceps can be inserted into he forceps conducting tube 9
before or after the forward end portion 3 is inserted in the
bronchi for the manipulation of the forceps during the inspection
of the object by means of the observation optical system comprising
the objective lens system 5, the image-transmitting fiber optical
system 6 and the ocular means 7. The pharmaceutical liquid such as
anesthetic can also be injected into the bronchi through the
pharmaceutical liquid injecting tube 10. Further, unwanted matter
such as phlegm in the bronchi can be sucked therefrom through the
forceps conducting tube 9 and the suction tube 11 by connecting the
suction device to the opening 11a of the suction tube 11 after the
forceps are withdrawn from the forceps conducting tube 9 and the
shutter blade 12 is moved to its closed position.
In order to prevent the forward end of forceps conducting tube 9
from being collapsed by the bending of the forward end portion 3 so
as to permit the unwanted matter to be sucked from the bronchi
through the forceps conducting tube 9 without hindrance when it is
used for removing the unwanted matter from the bronchi, a
thin-walled coarsely coiled strip 28 such as helically wound steel
strip may be provided around the portion adjacent to the forward
end of the tube 9 in the region in the forward end portion 3 of the
endoscope. The helically would strip 28 can be fixedly embedded in
the outer surface of the tube 9 by appropriately heating the tube 9
after the strip 28 is wound around the tube 9.
FIG. 9 shows the manner how the forward end portion of the
endoscope in accordance with the present invention is inserted in
the bronchi of a human body by the operation of the control
mechanism of the endoscope as described above.
The above-described construction of the endoscope in accordance
with the present invention enables the various elements necessary
for the inspection and surgical operation of the bronchi or the
like to be compactly housed in the forward end portion of the
endoscope having very small diameter such as 5.0 mm. or 5.5 mm. so
that the forward end portion of the endoscope can be easily and
smoothly inserted into the deep internal portion of the bronchi by
virtue of the convenient manipulation afforded by the control
mechanism of the present invention without injuring the inner wall
of the bronchi through which the forward end portion of the
endoscope in inserted and various operation necessary for the
inspection and the surgical operation of the bronchi can be freely
carried out.
FIGS. 10 to 12 show another embodiment of the flexible tube
assembly adapted to be incorporated in the forward end portion of
the endoscope constructed in accordance with the present
invention.
By this construction of the forward end portion of the endoscope,
the forward end portion can be bent not only in any desired
direction but also to different radii of curvature by the selective
actuation of the string means connecting the flexible tube section
of the forward end portion of the endoscope to the control
mechanism in the control housing through the elongated flexible
tube by the operation of the control mechanism.
As shown in FIG. 10, the forward end portion of the endoscope
comprises a forward end section I and a flexible tube section II. A
lens barrel 30 mounting therein a cover glass 31 and an objective
lens system 32 is secured in the forward end section I. A coarsely
helically coiled strip 33 forming a flexible tube such as that made
of thin steel strip or steel wire constitutes the flexible tube
section II. The forward end of the helically coiled strip 33 is
connected to he rearward end of the lens barrel 30 while the
rearward end of the helically coiled strip 33 is connected to the
elongated flexible tube designated by the reference numeral III. As
shown in FIG. 10, the image-transmitting optical system 34 such as
a fiber optical system extends from the forward end section I
through the flexible tube section II and the elongated flexible
tube III toward the control housing (not shown) as in the case of
the embodiment shown in FIGS. 1 to 8. The forward end 34a of the
fiber optical system 34 is located in the lens barrel 30 behind the
objective lens system 32 spaced an appropriate distance therefrom
in alignment therewith so that an image of the object to be
inspected is focused on the forward end 34a by means of the
objective lens system 32. The image of the object is transmitted
through the fiber optical system 34 to the rearward end thereof
(not shown) provided in the control housing as in the case of the
embodiment shown in FIGS. 1 to 8. Illuminating fiber optical
systems 35 (FIG. 11) also extend from the forward end section I
through the flexible tube section II and the elongate flexible tube
III to the control housing. The rearward ends of the illuminating
fiber optical systems 35 are illuminated by a light source (not
shown) so that the light is transmitted through the fiber optical
systems 35 to the forward ends thereof thereby permitting the light
to be emitted thereof thereby permitting the light to be emitted
therefrom so as to illuminate the object as in the case of the
embodiment shown in FIGS. 1 to 8. The illuminating optical systems
35 can be replaced by lamp means located in the forward end section
I to which the electric power is supplied through lead wire means
extending from the control housing.
Other elements such as a forceps conducting tube also serving as a
suction tube, a pharmaceutical liquid injection tube can also be
incorporated in the endoscope of FIG. 10 as in the case of the
embodiment shown in FIGS. 1 to 8.
The outer peripheral surfaces of the forward end section I, the
flexible tube section II and the elongated flexible tube III are
covered by a pliant sheath 36 such that comprises of a plastic tube
and a fine tubular metallic netting fitted in the plastic tube or
embedded therein so as to watertightly keep the assembly.
Now the mechanism for flexing the forward end portion of the
endoscope shown in FIGS. 10 to 12 will be described in detail.
In the similar way to that shown in FIGS. 1 to 8, a stay means 37
such as a resilient, relatively stiff steel wire is provided
longitudinally in the flexible tube section II adjacent to the
inner wall thereof. The forward end 37a of the stay means 37 is
secured to the rearward end of the lens barrel 30 while the
rearward end 37b of the stay means 37 is secured to the rearward
end of the flexible tube section II so that the flexible tube
section II is prevented from being unduly contracted as a whole by
virtue of the provisions of the stay means 37 serving as a backbone
of the flexible tube section II while the flexiblity of the
flexible tube section II is maintained.
A pair of strings 38, 39 extend from the forward end section I
through the flexible tube section II and the elongated flexible
tube III toward the control housing with the forward ends 38a, 39a
of the strings 38, 39 being secured to the lens barrel 30 as shown.
The location of the strings 38, 39 is such that they are located
opposite to each other with respect to the stay means 37 spaced
therefrom in cross section of the flexible tube section II as shown
in FIG. 11 in substantially symmetrical relationship to each other
with an angle A being formed between two lines connecting the
center of the stay means 37 and the centers of the respective
strings 38, 39 in cross section of the flexible tube section II as
shown in FIG. 11. The angle A may be either an obtuse angle or an
acute angle, preferably an angle other than 180.degree. . The
rearward ends of the strings 38, 39 are connected to a control
mechanism (not shown) provided in the control housing so that
either one or both of the strings 38, 39 can be selectively pulled
by the operation of the control mechanism.
As shown in FIG. 12, noncontractable pipes 40, 41 such as tightly
helically coiled wires forming the pipes extend through the
elongated flexible tube III and are slidably fitted on the strings
38, 39, respectively. The rearward ends of the noncontractable
pipes 40, 41 are fixedly secured to stationary points in the
control housing (not shown) so that the movement of the strings 38,
39 relative to their pipes 40, 41 at the rearward ends of the pipes
40, 41 as given by the operation of the control mechanism can be
exactly transmitted to the forward end portions of the strings 38,
39 at the forward ends of the pipes 40, 41 relative thereto. As
shown in FIG. 12, the forward end 40a of the pipe 40 terminates at
a position intermediate forward and rearward ends of the flexible
tube section II and secured to the inner wall of the flexible tube
section II thereat while the forward end 41a of the pipe 41
terminates at a position adjacent to the rearward end of the
flexible tube section II and secured to the inner wall of the
flexible tube section II thereat. In other words, the string 38
extends freely without being covered by the pipe 40 the distance
IIa between the rearward end of the lens barrel 30 and the forward
end 40a of the pipe 40 while the string 39 extends freely without
being covered by the pipe 41 the distance IIb which is greater than
the distance IIa between the rearward end of the lens barrel 30 and
the forward end 41a of the pipe 41. Thus, the actuation of the
string 38 causes the length IIa of the flexible tube section II to
be contracted while the actuation of the string 39 causes the
length IIb of the flexible tube section II to be contracted.
In operation, when only the string 38 is pulled by the operation of
the control mechanism the length IIa of the flexible tube section
II is bent in the direction from the stay means 37 toward the
string 38 in cross section of the flexible tube section II only in
the range of the length IIa, while the stay means 37 serves as a
backbone for the flexible tube section II to prevent it from being
contracted as a whole so that the radius of curvature of the
flexure of the flexible tube section II is made very small. In like
manner, when only the string 39 is pulled by the operation of the
control mechanism, the flexible tube section II is bent in the
direction from the stay means toward the string 39 in cross section
of the flexible tube section II in the range of the length IIb of
the flexible tube section II so that the radius of curvature of the
flexure of the flexible tube section II is made relatively large.
When both the strings 38, 39 are pulled simultaneously by different
amounts, then the flexible tube section II can be bent in any
desired direction within the angle A as viewed in the cross section
of the flexible tube section II with the radius of curvature of the
flexure of the flexible tube section II being made intermediate the
radii of curvature obtained when the respective strings 38 and 39
are pulled separately.
These features are extremely important in order to smoothly insert
the forward end portion of the endoscope into the bronchi having
very narrow tortuous paths without hindrance.
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