US3610231A - Endoscope - Google Patents

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.

Description

SEARCH RQOM United States" l 3,610,231

suasnrun: FOR MISSING Xe [72] Inventors N g g Tflkahashi; Primary Examiner-Richard A. Gaudet TEN") Ouchi boih of y l p Assistant ExaminerG, F. Dunne [2!] Appl. No. 7 A!t0rneyl(urt Kelman [22] Filed July 17,1968 [45] Patented Oct. 5, 1971 [73] Assignee Olympus Optical Company, Ltd. ABSTRACT: An endoscope especially adapted to inspect the Tokyo, ]apan v bronchi of a human body or the like and having a forward end [32] Priority July 21, 1967, Sept. 22, I967 portion and a control housing connected to the forward end [33] Japan portion through an elongated flexible tube. The forward end [3 l l 42/62666 and 42/81013 portion can be flexed by the control from the control housing M g so that it can be smoothly inserted into the bronchi. The en doscope is provided with an observation optical system, an il- Iuminating 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 ENDOSCOPE 1 without increasing the outer diameter of the forward end por- 4 Claims, 12 Drawing Figs. 0m

52 Us. Cl 128/6, To ensure Positive and exact flexing of the forward end P 95/11 EM tion, a stay means made of a resilient, relatively stiff wire is {51 1 Int. Cl A6lb 1/06 Pmvidsd longitudinally adjacent to the inner wall of the flexi- 123 4 5 6y ble tube section of the forward end portion. The both ends of 7 9 2; 95 1' 5; 138/120 the stay means are fixedly secured to the inner wall of the flex- I ible tube section at its forward and rearward ends so that the [56] References Cited stay means serves as a backbone to prevent the flexible tube UMT STATES PATENTS section from being unduly contracted as a whole while the flexibility of the flexible tube section is maintained. To effect [50] Field of Search 2975'785 128/6 the bending of the flexible tube section, string means extend 3,253,524 5/1966 Ashizawa 95/11 from the control mechanism through the elongated tube, the 3,4l7,745 12/1968 Sheldon 128/6 forward ends of the string means are secured to the inner wall FOREIGN PATENTS of the flexible tube section so that the flexible tube section can 830.639 W Gffial i n 2 be flexed by pulling the string means by the operation of the 4,699 9/1905 France control mechanism.

PATENTEQ 001 51971 SHEET '1 BF 2 :55. vii-Elm INVENTORS. HRGfiStMGG TAKAHASPH Tutu owzHl PATENT-ETD um i n 3.610.231

SHEET 2BF 2 INVENTOR MAGASH use TRKAH nsm T6113? 9 M H l ENDOSCOPE 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 ofthe bronchi ofa human body or the like must be very small such as the diameter of5.0 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 aboutl2 mm. for the in.- spection 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.

SUM MARY 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 disad vantages 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 flxed 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 smaller than the distance between the forward end of the flexil ble tube section and the forward end of the other of the noncontractable pipes. Since thebending 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 sewing 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 1 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. I 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. I 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. I;

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. I 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 ofthe 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 ofa human body;

FIG. I0 is a longitudinal sectional view of the forward end portion of an endoscope constructed in accordance with another feature of the present invention;

FIG. II is a cross-sectional view taken along the line 11-11 in FIG. I0; 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. I and 2 show an embodiment of the egdoscope constructed in accordance with one feature of thepresai'fihvention. The endoscope comprises a control housing I, an elongatedflexible tube 2 and aforward end portion 3. The control housing 1 is connected to the rearward end of the elongatedflexible tube 2 around which gripping-means 4 is provided for easy handling of the endoscope while the forward end of the elongatedflexible tube 2 is connected to theforward end portion 3. Theforward end portion 3 together with the elongatedflexible 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, anobjective lens system 5 is provided in a viewing window of theforward end portion 3 so that the light from an object to be inspected is'received through the viewing window by theobjective lens system 5 to thereby form an image of the object in the forward end portion 3v An image transmittingoptical system 6 such as a fiber optical system extends from theforward end portion 3 through the elongatedflexible tube 2 to the control housing 1. The forward end of the image-transmitting fiber optical sy stern is located in the forwarde'iid portion Sin opposin g r el'at'fin'to theobjective lens system 5 in alignment therewith so that the image of the object is focused on the forward end of the image-transmittingoptical system 6 thereby permitting the image to be transmitted through the image transmittingoptical system 6 to the rearward end thereof. An ocular means 7 is provided in the control housing I which is located in 0p posing relation to the rearward end of the image-transmittingoptical system 6 in alignment therewith so that the image of the object thus transmitting to the rearward end of the imagetransmittingoptical system 6 is viewed through the ocular means 7. An illuminating f beroptical system 8 extends from theforward en'dpo'rtion 3 through the elongatedflexible tube 2 to the control housing with the forward end thereof being in alignment with an illuminating window provided in theforward end portion 3 while the rearward end thereof being in alignment with an illuminating window provided in theforward end portion 3 while the rearward end thereof terminates in a mounting 8a provided in the control housing I. 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 fiberoptical 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 fiberoptical system 8 through the illuminating window in theforward end portion 3 so as to illuminate the image to be inspected. Aforceps conducting tube 9 and a pharmaceutical liquid injecting tube 10 also extend from the forward end of theforward end portion 3 through the elongatedflexible tube 2 to the control housing I with the rearward end of theforceps conducting tube 9 terminating at an opening 90 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 I. Thus, the forceps (not shown) are inserted from the opening 90 into theforceps conducting tube 9 therethrough so as to be projected from the forward end of theforward 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 theforward 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 thercofso that the pharmaceutical liquid is injected into the bronchi.

Theforceps conducting tube 9 is provided with a suction tube I1 branched from theforceps conducting tube 9 in the control housing I and terminating at an opening Ila which is provided in control housing 1. Means for closing theforceps conducting tube 9 such as ashutter blade 12 is provided in thetube 9 at a position intermediate the rearwardend of thetube 9 and the position at which thesuction tube 11 is branched from thetube 9. Aknob 12a for manually actuating theshutter blade 12 is attached thereto and projects outwardly from the control housing 1 so that theshutter blade 12 is opened and closed by the manual operation of theknob 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 theforward end portion 3 of the endoscope is inserted. ln this case, the forceps are withdrawn from the endoscope and theshutter blade 12 is moved to its closed position by the operation of the knob 120. Thus, when the suction device is operated, the unwanted nlutter such as the phlegm in the bronchi can be taken out from the bronchi through theforceps conducting tube 9 and thesuction 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 theforward end portion 3 of the endoscope. Theforward end portion 3 comprises aforward endplate 14, arearward end 15 such as an annular ring and aflexible tube section 13 such as a coarsely helically coiled steel strip forming a tubelike shape which flexible connected theforward end plate 14 and therearward end 15. As shown in FIG. 8, theforward end plate 14 is provided with the viewing window with which theobjective lens system 5 in theforward end portion 3 is located in alignment, the illuminating fiberoptical system 6 is located in alignment, opening connected to the forward end of theforceps 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 stiffwire extends longitudinally along the inner wall of theflexible tube section 13 adjacent thereto. The

forward end 160 of the stay means 16 is connected to theforward end plate 14 while therearward end 16b of the stay means 16 is fixedly connected to the forward end of the elongatedflexible tube 2 adjacent to therearward end 15 of theforward end portion 3 so that the stay means 16 serves as a backbone of theflexible tube section 13 of theforward end portion 3 to prevent theflexible tube section 13 from being unduly contracted as a whole when it is subjected to an external force tending to contract theflexible tube section 13 while it is allowed to be bent thereby. A pair ofstrings 17, 18 extend from theforward end portion 3 through the elongatedflexible tube 2 to the control housing l. The forward ends17a 18a of thestrings 17,18 are connected to theforward end plate 14 at positions opposite to each other with respect to the position at which theforward end 16a of the stay means 16 is connected to theforward end plate 14.Further string 19 extends from theforward end portion 3 through theelongated tube 2 to the control housing 1. Theforward end 19a of thestring 19 is connected to theforward end plate 14 at a position substantially diametrically opposite to the position at which the forward end 160 of the stay means 16 is connected to theforward end plate 14.

A control mechanism comprising two manuallyrotatable discs 20, 21 having the common axis of rotation 22 is provided in the control housing 1. Either of thediscs 20,21 may be provided with projections 200 and/or 210 (only theprojection 20a is shown) respectively, which project from the control housing 1 so as to be manually actuated selectively so that either or both of thediscs 20, 21 are rotated. Alternatively, the outer periphery of each of thediscs 20,21 is provided with a knurled surface a part of which projects from the control housing 1 thereby permitting either or both ofthediscs 20,21 to be manually rotated selectively by means of the knurled surfaces of thediscs 20, 21. The rearward ends 17!; 18b of thepair ofstrings 17, 18 are connected to thedisc 20 at positions diametrically opposite to each other so that the manual rotation of thedisc 20 in one direction causes one of thestrings 17, 18 to be pulled while the other of thestrings 17, 18 is loosened and vice versa. The rearward end 1912 of thefurther string 19 is connected to thedisc 21 so that thestring 19 is pulled by the manual rotation of thedisc 21 in one direction.

. Brake means 23, 24 such as friction pads may be provided for thediscs 20, 21, respectively so that thediscs 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 elongatedflexible tube 2 and are slidably fitted on thestrings 17, 18 and 19, respectively, with the rearward ends25a 26a and 27a thereof being fixedly secured to stationary points in the control housing 1 while the forward ends of thepipes 25, 26 and 27 terminate at therearward end 15 of theforward end portion 3 of the endoscope and secured thereto, so that the movement of thestrings 17, 18 and 19 relative to thenoncontractable pipes 25, 26 and 27, respectively, as given at the respective rearward ends of thestrings 17, 18 and 29 by the operation of the control mechanism can be exactly transmitted to the forward ends ofthestrings 17, 18 and 19 relative to the respective forward ends ofpipes 25, 26 and 17, respectively. 1

In operation, theforward end portion 3 can be bent towar the right as viewed in FIGS. 5 and 6 by pulling only thestring 19 by the manual operation of thedisc 21 in the direction of the arrow shown in FIG. 4. Under this condition, when thedisc 20 is manually rotated in the direction shown by the arrow in FIG. 4, thestring 17 is pulled while thestring 18 is loosened so that theforward end portion 3 is bent in the direction shown by the arrow a in FIG. 6. When thedisc 20 is rotated in the opposite direction, theforward end portion 3 is bent in the direction, theforward end portion 3 is bent in the direction shown by the arrow bin FIG. 6.

It is apparent that the pulling of only of thestring 17 or 18 causes theforward end portion 3 to be bent further upwardly or downwardly as viewed in FIG. 6. Therefore, theforward end portion 3 can be bent in any direction within a predetermined solid angle determined by the flexure of theflexible tube section 13 by selectively actuating thestrings 17, 18 and 19 by means of the control mechanism. The stay means 16 serves as a backbone to prevent theflexible section 13 from being unduly contracted as a whole by the actuation of thestrings 17, 18 and 19 while the flexibility of theforward end portion 3 is maintained.

The brake means 23, 24 frictionally hold thediscs 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 conductingtube 9 before or after theforward 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 theobjective lens system 5, the image-transmitting fiberoptical system 6 and the ocular means 7. The pharmac'eutical 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 theforceps conducting tube 9 and thesuction tube 11 by connecting the suction device to the opening of thesuction tube 11 after the forceps are withdrawn from theforceps conducting tube 9 and theshutter blade 12 is moved to its closed position.

ln order to prevent the forward end offorceps conducting tube 9 from being collapsed by the bending of theforward end portion 3 so as to permit the unwanted matter to be sucked from the bronchi through theforceps conducting tube 9 without hindrance when it is used for removing the unwanted matter from the bronchi, a thin-walled coarsely coiledstrip 28 such as helically wound steel strip may be provided around the portion adjacent to the forward end of thetube 9 in the region in theforward end portion 3 of the endoscope. The helically would strip 28 can be fixedly embedded in the outer surface of thetube 9 by appropriately heating thetube 9 after thestrip 28 is wound around thetube 9.

HO. 9 shows the manner how the forward end portion of the endoscope in accordance with the present invention is inserted in the bronchi ofa 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. .0 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. 1

By this construction of the forward end portion of the en doscope, 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. Alens barrel 30 mounting therein acover glass 31 and anobjective lens system 32 is secured in the forward end section I. A coarsely helically coiledstrip 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 coiledstrip 33 is connected to he rearward end of thelens barrel 30 while the rearward end of the helically coiledstrip 33 is connected to the elongated flexible tube designated by the reference numeral 111. As shown in FIG. 10, the imagetransmittingoptical 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 Ill toward the control housing (not shown) as in the case of the embodiment shown in FIGS. 1 to 8. Theforward end 34a of the fiberoptical system 34 is located in thelens barrel 30 behind theobjective lens system 32 spaced an appropriate distance therefrom in alignment therewith so that an image of the object to be inspected is focused on theforward end 340 by means of theobjective lens system 32. Their'nage of the object is transmitted through the fiberoptical 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 111 to the control housing. The rearward -ends of the illuminating fiberoptical systems 35 are illuminated by a light source (not shown) so that the light is transmitted through the fiberoptical 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 illuminatingoptical 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. as in the case of the embodiment shown in FIGS. 1 to 8.

The outer peripheral surfaces of the forward end section 1, the flexible tube section II and the elongated flexible tube III are covered by apliant 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, astaymeans 37 such as a resilient, relatively stiff steel wire is provided longitudinally in theflexible tube section 11 adjacent to the inner wall thereof. The forward end 370 of the stay means 37 is secured to the rearward end of thelens barrel 30 while therearward end 37b of the stay means 37 is secured to the rearward end of theflexible tube section 11 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 theflexible tube section 11 while the flexiblity of theflexible tube section 11 is maintained.

A pair ofstrings 38, 39 extend from the forward end section I through the flexible tube section II and the elongated flexible tube Illtoward the control housing with the forward ends 380, 39a of thestrings 38, 39 being secured to thelens barrel 30 as shown. The location of thestrings 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 theflexible tube section 11 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 therespective 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. The rearward ends ofthe strings 38, 39 are connected to a control mechanism (not shown) provided in the control housing so that either one or both of thestrings 38, 39 can be selectively pulled by the operation of the control mechanism. I

As shown in FIG. 12,noncontractable pipes 40, 41 such as tightly helically coiled wires forming the pipes extend through the elongated flexible tube Ill and are slidably fitted on thestrings 38, 39, respectively. The rearward ends of thenoncontractable pipes 40, 41 are fixedly secured to stationary points in the control housing (not shown) so that the movement of thestrings 38, 39 relative to theirpipes 40, 41 at the rearward ends of thepipes 40, 41 as given by the operation of the control mechanism can be exactly transmitted to the forward end portions of thestrings 38, 39 at the forward ends of thepipes 40, 41 relative thereto. As shown in FIG. 12, the forward end 40a of thepipe 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 thepipe 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, thestring 38 extends freely without being covered by thepipe 40 the distance lla between the rearward end of thelens barrel 30 and the forward end 400 of thepipe 40 while thestring 39 extends freely without being covered by thepipe 41 the distance 1117 which is greater than the distance Ila between the rearward end of thelens barrel 30 and the forward end 410 of thepipe 41. Thus, the actuation of thestring 38 causes the length Ila of the flexible tube section II to be contracted while the actuation of thestring 39 causes the length llb of the flexible tube section II to be contracted.

.In operation, when only thestring 38 is pulled by the opera tion of the control mechanism the length lla of the flexible tube section II is bent in the direction from the stay means 37 toward thestring 38 in cross section of theflexible tube section 11 only in the range of the length Ila, while the stay means 37 serves as a backbone for the flexible tube sectionll to prevent it from being contracted as a whole so that the radius tube section ll is made relatively large. When both thestrings 38, 39 are pulled simultaneously by different amounts, then the flexible tube section ll can be bent in any desired direction within the angle A as viewed in the cross section of the flexible tube section ll with the radius of curvature of the flexure of the flexible tube section ll being made intermediate the radii of curvature obtained when therespective strings 38 and 39 are pulled separately. 1

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.

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.

2 The device as defined in claim I 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 I 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 ofsaid strings.

Claims (3)

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. CM,2Evice 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.

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