Note: Descriptions are shown in the official language in which they were submitted.
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1 This application is a divisional of application
Serial No. 443,199 filed December 13, 1983.
this invention relates to an endoscope for image-
observing or measuring an area-filled with an opaque liquid.
It has been known that an area filled with an opaque liquid
such as a blood vessel or the internal wall of the heart of a
living body may be observed by the use of an endoscope
having a means for providing a field of vision by a trays--
parent fluid.
Fig. 1 is a schematic view for explaining the
principle of an endoscope,
Fig. 2 it a view showing one example of the leading
end portion owe conventional.endoscope with a transparent
fluid flush means,.
Figs. 3 Andy are longitudinally sectional and end
elevation Al views respectively, of a conventional ennui-
scope Wyeth transparent balloon;
Fig. 5 is a view showing the observation operation
of the internal wall of the heart of living body by the
conventional endoscope with a transparent balloon;
Figs. 6 and 7 are views showing an unstable field of
vision caused by the swaying of the transparent balloon at
thy joint thereof in the conventional endoscope;
Figs. 8 and 9 are longitudinally sectional and end
elevational.views, respectively, of the leading end port
lion of the endoscope according to the first embodiment
of the present invention;
Figs. lo and 11 are-views showing the operational
modes of the endoscope of the first embodiment for observe
in a flat object such as the internal wall of the heat
of a living body and a narrow field such as that in a
brood vessel, respectively;
Fig. 12 is a sectional view showing the expansion
Rand contraction of the resilient hood in the endoscope
according to first embodiment of the present invention.;
Figs. 13, 14 and 15 are side elevation Al, end Elena-
tonal and longitudinally sectional views, respectively,
of the leading end portion of the.endoscope according to
the second embodiment ox the present invention;
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1 Fig. 16 is a view showing the inflated condition of
the transparent balloon on the endoscope shown in Fig. 13;
Fig. 17 is a longitudinally sectional view of the
leading end portion of the endoscope according to the third
embodiment of the present invention;
Fig. 18 is a view showing the inflated condition of
the transparent balloon on the endoscope of Fig. 17:
Fig . 19 is a view of a modification of the Solon-
Dracula portion in the embodiment shown in Fig, 17;
Fig. 20 is an explanative view of the endoscope with
a transparent balloon according to the fourth embodiment of
the present invention in which Fig. aye shows the Cowan-
lion of the endoscope prior to inflation of the balloons
thereof and Fig. 20(b~ shows the condition of the endoscope
after inflation of the-balloons thereof; and
Fig. 21 it a view showing one specific example of
the fourth embodiment of the invention in which Fig. aye
is a view showing how to fabricate the endoscope and
Fig. 21(b~ is a view showing the endoscope after inflation
of the two balloons thereof.'
Fugue is a schematic view-showing the principle of
such an endoscope. on Fig. 1, 1 denotes a tube or catheter
to be inserted into a living body, 2 denotes a blood vessel
within the living body and 3 denotes an image fiber.
Basically, the image fiber 3 is inserted into the catheter
1 and a transparent fluid is passed through the catheter 1
and it flushed into an observation area within the living
- body whereby the internal conditions of the body can be
observed through the image fiber.
Fig. 2 shows one example of the leading end portion
of the conventional endoscope provided with a transparent
fluid flush means as a means for providing a field of vision.
In Fig. 2, 3 denotes an image fiber for transmitting an
image from the observation area to an optical system or
measuring system not shown, 4 denotes light guide for
transmitting illumination light from a light source not
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1 shown to the observation area, 5 denotes a cylindrical
lens set, 6 denotes a prism and 7, 8 denote advancing
directions of transparent fluid and illumination light. The
transparent material which may be a saline, is directly
s flushed from an outlet 9 into a blood vessel of a living
body, for example, to dispel the blood from the observation
area, whereby a transparent field of vision is formed in
the blood vessel and the internal conditions of the blood
vessel can be observed.
In this conventional endoscope shown in Fig-. 2,
however, since the field of vision must be maintained in a
condition which is free of blood and is transparent by
- continuously excluding the flow of blood, a constant flow
of a great amount of transparent fluid, usually an amount
substantially corresponding to the amount of fluid flow
within the blood vessel, must continuously be supplied to
the area during the observation operation. the endoscope
adapted to be inserted into a living body for observation of
the living body preferably has as small an outer diameter
as possible. However, in the endoscope shown in Fig. 3, in
order to supply the transparent fluid in a great amount as
mentioned hereinabove, the outer diameter of the endoscope
becomes of necessity rather large. In addition, the supply
of the transparent fluid in a great amount also requires
the use of a specific electrically driven power cylinder
to increase the supplying pressure of the transparent fluid.
In order to supplement such defects of the convent
tonal endoscope above stated, another type of endoscope
having transparent balloon as a means for providing a
field of vision at the leading end thereof has been pro-
posed and has become conventionally known.
Figs. 3 and 4 show longitudinally sectional and end
elevation Al views, respectively, of a conventional endow
; scope lo with a transparent balloon.
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1 In these Figures, pa denotes an image fiber, pa
denotes a lens, pa denotes light guides, pa denotes a
transparent fluid transport passage, pa denotes a fluid
outlet, if denotes a transparent balloon and 12 denotes a
sheath. The transparent balloon 11 is secured to the
sheath 12 by adhesive and binding means (not shown). When
the internal wall of the heart of a living body is
observed, for example, by inserting the endoscope into
the living body, a transparent fluid such as COY gas or
a saline is passed through the transparent fluid transport
passage pa and discharged through the fluid outlet pa to
inflate the transparent balloon 11 at the leading end of
the endoscope whereby a transparent field of vision IS
forehand within the inflated transparent balloon 11.
Fig. 5 shows a conventional endoscope with a trays-
parent balloon being used for the observation of the inter-
net wall of the heart of a living body. The transparent
balloon 11 inflated with the transparent fluid provides a
transparent area 14 in contact with the heart's internal
wall 13 between the endoscope and the heart's internal
wall 13 whereby opaque blood 15 is excluded from the obser-
ration area to provide a field of vision for observation.
However, the above mentioned conventional endoscope
with the transparent balloon has a small or insufficient
support area for the large size of the transparent balloon
11 when inflated and, thus, has a low or insufficient
support capacity for the balloon. For this reason, when
the endoscope is inserted into a living body for the
observation of the internal conditions of the living body,
the inflated balloon 11 attached to the leading end of the
endoscope sways at the joint between the endoscope body
and balloon-when subjected to a variation in the feed
pressure of the transparent fluid and/or the reaction
force from the living body tissue to be observed. Thus, the
conventional endoscope with the transparent balloon has the
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1 disadvantage that the yield of vision tends to ye unstable
during the observation operation. This sway of the balloon
becomes greater when the-thickness of balloon wall is made
thinner in order to increase the transparency of the balloon.
Figs, 6 and 7 show examples of the unstable conditions
of the field of vision caused by the swaying of the in-
fluted balloon at the joint between the endoscope body
and balloon during the observation operation when subjected
to outer force as shown by the arrows.
. 10 Therefore, the principal object of the present in-
mention into eliminate the disadvantages inherent in the
conventional endoscopes for optically observing or measuring
an observation area filled with an opaque.liquid.and to
provide an improved.endoscope which can provide a stable
field of vision with a minimum amount of transparent flute
during the observation operation.
According to the present invention, an endogcope
. for image-observing.or measuring an area filled with an
opaque liquid comprises; an image fiber; a lens positioned
at the leading end of said image fiber; a light guide
arranged in parallel to said image fiber; a transparent
fluid transport . passage arranged in parallel to said
image fiber and light guide and having an outlet at the
leading end thereof; a-sheath enclosing said image fiber,
lens, light guide and transparent fluid transport passage;
and a means for providing a field of vision at said leading
. end of said endoscope by the transparent fluid; and it is
further characterized by a means for stabilizing said fiend
of vision formed by the field of vision providing means
which stabilizing means is provided on the leading end
portion of said sheath.
In one preferred example of the invention, said
field of vision providing means comprises a flush of said
transparent fluid directly spouted out from said outlet
of said transparent fluid transport passage into said
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1 opaque liquid and said stabilizing means comprises an
expandable hood surrounding said lens the outlet of said
transparent fluid transport passage, the leading end of
the light guide and the flush of the transparent fluid. By
this arrangement the field of vision is obtained stably
at the observation area by a relatively small amount of
transparent fluid and as a result, a transport passage
of a relatively small diameter may be used for the trays-
parent fluid, and thus the outer diameter of the endoscope
can also be reduced and, at the same time, any specific
electrically driven power cylinder for supplying the
transparent fluid can be eliminated.
In another preferred example of the invention, said
field of vision providing means comprises a transparent
balloon provided at the leading end of said-endosc~pe and
is inflatable by said transparent fluid supplied from said
passage and said stabilizing means comprises a balloon
support formed by substantially cylindrical and resilient
material and.providea at the leading end portion Go the
endoscope encircling the portion which forms the joint
. Tony the balloon and the endoscope body so as to support
the balloon joint portion when the balloon is inflated or,
alternatively a support balloon mounted on said sheath
at the leading end portion of the endoscope behind said
transparent balloon for supporting the backside of the
same when said two balloons. are inflated. By such arrange-
mints also, the field of vision is obtained stably with a
minimum amount of the transparent fluid being required.
.. Many.other.advantages, features and additional
objects of the present invention will become apparent to
persons skilled in the art upon making reference to the
following description and the accompanying drawings which
show preferred embodiments of the present invention by
way of illustrative example.
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1 Figs. 8 and 9 are cross-sectional and front
elev~tional views of the leading end portion of the
endoscope lob of the first embodiment of the invention,
respectively. In these Figures, 3b denotes an image fiber,
S 4b denotes a light guides doughnuts lens and 7b
denotes transparent fluid transport passage These
components are enclosed as a unit in a sheath 12b.
The leading end of the transparent fluid transport passage
7b is formed with an outlet 9b.. A resilient hood 16 is
formed at the.~leading.end of the sheath 12b Asian integral
extension of the sheath and encircles the leading ends
of the passage 7b, lens Sub and light guide 4b.
: Figs.- 10 and 11 show the operation modes of the
endoscope of the first embodiment for observing the inter-
net conditions of a living body. Fig. 10 shows the
operation mode of the endoscope for observing a flat object
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at an area for observation such as the internal wall 13 of
the heart or the like, for example. Fig. 11 shows the
operation mode of the endoscope for observing the internal
conditions of a living body in the direction opposite to
the flow direction of the blood 15 in relatively large
blood vessel 2 such as thefem~ralartery, for example.
The hood 16 holds the transparent fluid 17 such as a
saline in a stable condition at a limited area to be
observed excluding the blood therefrom to thereby provide
the field of vision free of blood 15 with a small amount ox
transparent flow as a whole. That is, the observation
is made possible through the transparent area defined by
the hood adjacent to the light guide 4b and lens Sub.
As shown in Fig. 12, the resilient hood 16 is
expanded, as shown by reference character A, only when
necessity arises, by inflating a balloon device 18 provided
in the wall of the hood 18 and this hood may normally be
kept in a deflated state as shown by reference character B.
Thus, when the endoscope is inserted into the blood vessel,
20 the hood 16 is contracted so that the endoscope can be
easily inserted into the blood vessel and after the endow
scope has been inserted into the blood vessel, the hood 16
is expanded whereby the observation area is easily formed.
With the above-mentioned construction and arrange-
mint of the components of the endoscope of this first embodiment, a field of vision can be effectively formed in
the observation area by the transparent fluid in a rota-
lively small amount. As a result, the diameter of the
transparent fluid transport passage can be reduced and
i 30 thus, the outer diameter of the endoscope can also be
reduced. Furthermore, as the reduced amount of the
transparent fluid required a lower pressure for supplying
the fluid, the endoscope can be operated by merely
manipulating a manual cylinder for pushing the fluid
(not shown) without the need of a specific electrically
driven power cylinder.
Figs. 13, 14 and lo are side elevation Al, end
elevation Al and longitudinally sectional views, respective-
lye of the second embodiment of the invention. The
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endoscope lo of this second embodiment includes a sub-
staunchly cylindrical, flexible and resilient balloon
support. More specifically as shown in Fig . 13, the Russell-
en leading end portion of the outer peripheral portion of
the endoscope contiguous to a sheath 12c is substantially
cylindrical and is divided into a plurality of resilient
pieces 19 by a plurality of slits which extend axially and
inwardly from the outer edge. The leading end portion of
the outer periphery of the endoscope is formed of deform-
able synthetic resin such as polyethylene or vinyl chloride or metal such as phosphor bronze. In Figs. 14 and 15, the
same reference numerals, with the addition of sub-reference
characters, denote the same components as those in the
endoscope shown in Figs. 3 and 4. The transparent balloon
tic is fitted in the sheath 12c and adhered to the sheath
at the area 20. As more clearly shown in Fig. 16, when
the balloon tic is inflated, the resilient pieces 19 are
subjected to the force resulting from the inflation of
the balloon and deform radially outwardly from the bases
to the outer ends of the resilient pieces in the form of
a petal whereby the inflated balloon can be supported
adjacent to the joint 20 over a wide range defined by
the inner area of all the resilient pieces.
Fig. 17 is a longitudinally sectional view of the
third embodiment of the invention. The endoscope lo of
this embodiment includes a substantially cylindrical,
flexible and resilient balloon support 20 at the leading
end portion of the endoscope. In Fig. 17, the same refer-
once numerals, with addition of sub-reference characters,
denote the same components as those in the embodiment
shown in Fig. 15. Although, the end elevation Al view of
the third embodiment is omitted, the light guide is
arranged in the same manner as in the embodiment of
Fig. 14. The leading end portion of the outer periphery
- 35 of the endoscope which is contiguous to the sheath 12d
is formed of extensible material such as natural rubber or
urethane and provides the cylindrical support 20 which
gradually decreases in wall thickness towards the leading
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edge. The balloon lid is fitted in and adhered to the
interior of the sheath 12d in the same manner as described
in connection with the balloon shown in Fig. 13, but is
not confined at the leading portion of the sheath Dwight
S a clearance formed by the gradual decrease in the wall
thickness of the sheath. As more clearly shown in Fig. 18,
wren the balloon lid is inflated, the inner purrer Of
: the cylindrical support 20 is subjected to the force
resulting from the inflation of the balloon and deforms
to expand towards the leading end of the support whereby
the transparent balloon can be supported adjacent to the
joint thereof over a wide range defined by the inner area
of the' cylindrical Support 20. The cylindrical support
20 may be in the form of a resilient cap 21, formed
lo separately from the sheath 12d, as shown in Fig. 19.
With the above mentioned construction and arrange-
mint of the components of the endosco~e with a transparent
balloon of the second and third embodiments, since the
flailed of vision is formed by inflating the transparent
balloon with the minimum amount of transparent fluid, the
outer diameter of the endoscope can be made relatively
stall. Also, since the transparent balloon can be support-
en in stabilized condition adjacent to the joint thereof
- . over Audi range by the flexible and resilient support,
'' 25 when the internal structure of a living body is observed
by the use of the endoscope, the position of the inflated
balloon will not readily change even when the balloon is
subjected to variation in the extraction and feed pressure.
in the endoscope and/or the reaction force from the living
body internal structure. Thus, a stable field of vision
can be maintained during the observation operation.
Furthermore, when the transparent balloon deflates, since
the support formed of the flexible and resilient member
returns from the expanded condition to the initial con-
'` 35 treated condition, the endoscope can be inserted into the
interior of a living body to be observed without dip-
faculty.
Figs. 20 and 21 show the fourth embodiment of the
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present invention. the endoscope lye of this embodiment
includes a transparent balloon tie at the leading end of
the endoscope as a field of vision providing means and a
support balloon 21 on the sheath ye at the leading end:
S portion of the endoscope behind the balloon tie. Fig. 20(~)
shows the balloons tie, 21 in their position prior to
inflation. In the illustrated embodiment, the balloon tie
is inflated by the transparent fluid from the leading end
of the transparent fluid transport passage lo and the
lo support balloon 21 is inflated by a bypass fluid from a
bypass hole 22 opened to the passage ye.
Fig. 20(b) shows the balloons in their inflated
position. the interiors of these balloons are maintained
at the same pressure. In the inflated position of thy
balloons as shown in Fig. 20(b), the balloons tie, 21
contact each other to prevent the transparent balloon from
displacing That is, the support balloon 21 supports the
back side of the balloonlle and prevents~heballoon tie from
deforming when the balloons are inflated whereby the field
of vision of the endoscope is maintained in a stable state.
Incidentally, it is preferable that separate fluid
passages are provided for the two balloons and toe internal
pressure of the support balloon is maintained hooks than
that of the transparent balloon to give a higher rigidity
to the support balloon. The two balloons, and particularly
the support balloon, are preferably formed of natural rubber
or the like so that the balloons can be made as thin as
possible and inflated to a substantial degree.
one specific example of this fourth embodiment will
be now described below referring to Fix. 21. A natural
rubber cap having the thickness ox 0.03 mm is fitted on a
stainless steel pipe 23 having an outer diameter of 2.7 mm
and the cap is tied at the rear end and at an intermediate
point of the cap by means of a string 24. The first bet-
loon tie is formed by the cap portion positioned forwardly of the intermediate tied point of the cap and the support
balloon 21 is formed by the cay portion between the inter-
mediate tied point and the tied rear end of the cap
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hole 22 of 0.5 mm diameter is formed in the wall of the pipe
23 at the area where the support balloon 21 is positioned.
A syringe 24 is attached to the rear end of the pipe 23
and when air under pressure of about 0.3 kg/cm2 is
introduced into the assembly, the first and support balloon
tie, 21 are inflated as shown in Fig. 2l(b1. When the first
balloon tie is pressed against a suitable wall, it is
apparent that the deformation of the first-mentioned
balloon controlled by the support balloon is smaller
lo than that of the transparent balloon of the conventional
endoscope which has no support balloon. In Fig. 21, the
other dimensions are as follows. Lo = 12 mm, Lo = 6 mm,
Lo = 3.5 mm, Lo = 4 mm, Lo = about lo mm, Lo = about 5 mm,
Do 2.7 mm and Do = about 12 mm.
}S With the above mentioned construction and arrange-
mint of the components of the endoscope of the fourth
embodiment, the outer diameter of the endoscope can be
made relatively small due to the same reasons stated in
conjunction with the second and third embodiments. Also,
yin this fourth embodiment, since the support balloon
provides the same pushing effect as that which would be
provide by a semi-rigid plate if such a plate were
provided behind the first balloon to prevent the displace-
mint of the deformation of the first balloon, the field of
vision is made stable and the first balloon can be made a
inn and transparent as possible.
Further, in this fourth embodiment, since a support
member can be provided on the endoscope without sub Stan-
tidally increasing the diameter of the latter, the endoscope
can be quite easily inserted into the living body.
In the foregoing, although description has been made
of the application of the endoscope of the invention to the
observation of the internal structure of a living body,
the endoscope can be also applied to a wide range of fields
including various industrial and optical observation
devices which provide a field of vision in an observation
area filled with an opaque liquid.
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