US3294085A - Endoscope - Google Patents

Description

United States Patent Ofice 3,294,085 Patented Dec. 27, 1966 3,294,085 ENDOSCOPE Frederick J. Wallace, New York, NY., assigner to American Cystoscope Makers, lne., Pelham Manor, NPY., a corporation of New Yorlr Filed Sept. 27, 1963. Ser. No. 312,167 6 Claims. (Cl. 12S-6) This application is a continuation-in-part of my copending application, Serial No. 305,304, filed August 29, 1963, now U.S. Patent 3,261,349 issued July 19, 1966.

This invention relates to electro-surgical instruments for endourethral surgery, and more particularly relates to such instruments which utilize optic fibers for the illumination of internal body orifices for purposes of examination and treatment.

An endoscope must meet limitations of size and shape dictated by the anatomical structure of the orifice in which it is to be used. Also, an endoscope must provide for light, vision and operating instruments or high frequency electrodes. For precision in diagnosis or other procedure, a fine, brilliant image that is accurate in regard to both color and definition is essential to the operator. Within the relatively small lumen or space inside the tubular portion of known endoscopes, there is a complete electrical circuit of which a lamp is a part. The lamp circuit requires an insulated conductor or wire to carry current from a contact near the proximal end, to the lamp frequently located at the distal end. The circuit must function perfectly under water and must not be affected by other solutions during sterilization, a requirement most diicult to fulfill in any electrical structure. While the instruments are water-tight when they leave the factory, due to the fact that they must be opened for the replacement of lamps, their ability to exclude moisture is almost entirely dependent upon the care exercised by the user in again sealing the instruments.

In known endoscopic instruments most premature burning out of lamps results from attempts to obtain unusually brilliant illumination. The extent of illumination is limited by the filament of the lamp itself. It is the practice to make use of a current regulator and observe the lamp filament closely while gradually increasing the current. The limit of safe current is reached when the definite reddish tint of the lamp suddenly becomes white. Further increase in illumination by increasing the current beyond this point results in premature burning out of the lamp. Once the lamp burns out it is necessary to remove it, thus introducing the possibility of the problems described above.

Problems also arise from the disinfection of parts of the endoscope containing lamps or lenses. It is not practicable to boil or autoclave any part of the endoscope which contains lamps. The usual chemical disinfectants may not be used or leaks and short circuits in the wiring may follow. As a result it is necessary to use special disinfectant methods and solutions in cleaning known endoscopes.

Resectoscope sheaths are used with electro-surgical instruments employing high frequency current for the resection of tissue. These sheaths are usually made from reinforced plastic of high dielectric strength such as linenbased Bakelite, melamine, Teflon, etc., in order to prevent any arcing of high frequency current to tissue which is not under resection. Heretofore, the telescopes which were used with electro-surgical instruments utilized a selfcontained lamp which produced about 1.5 foot candles at a one inch working distance.

It is an object of the present invention to provide means for illuminating internal orifices which means provide significantly brighter illumination than was heretofore possible and which may be sterilized by boiling, autoclaving or chemicals without deleterious results.

It is another object of the present invention to provide endoscopic instruments having illuminating means with an expected life, equivalent to that of the rest of the instrument, which means do not require maintenance or replacement of parts of normal use.

It is still another object of the present invention to provide resectoscope sheaths utilizing as an illuminating means a bundle of optic fibers which may be shaped at its distal end to configurations especially adapted to the particular use of the instrument.

It is another object of this invention to provide a fiber optic bundle for the illumination of internal orifices which is in a form rigid enough for insertion into such orifices.

Further objects as weil as advantages of the present invention will be apparent from the following description and the vaccompanying drawings, in which:

FIGURE l is a side elevational view of an electrosurgical instrument constructed in accordance with the present invention and showing the electrode in its retracted position, partially broken away for convenience in understanding and describing the invention;

FIGURE 2 is a transverse cross-sectional view taken generally along lines 2 2 of FIGURE l;

FIGURE 3 is a transverse crosssectional view taken generally along lines 3-3 of FIGURE l;

FIGURE 4 is an end view of the electro-surgical instrument of FIGURE l;

FIGURE 5 is a sectional detail view of the means for connecting the sheath to the remainder of the electrosurgical assembly;

FIGURE 6 is an elevational view of the resectoscope sheath of this invention partially broken away for convenience in understanding and describing the invention; and

FIGURE 7 is an enlarged crossscctional detail of a sheath utilizing another embodiment of this invention.

The objects of this invention may be accomplished by forming a resectoscope sheath from two concentric, coaxial, rigid tubes. The concentric tubes may be circular in cross-section but for some applications are preferably slightly elliptical. Also for some applications it is desirable to taper the concentric tubes. A bundle containing a large number of optic fibers is placed in the annular space between the two tubes. The proximal end of the optic fiber bundle may be formed into a solid rod which is of a suitable configuration, preferably cylindrical, for coupling to a source of light. Because endoscopes are shaped to conform to the orifice being examined, the distal end of the bundle may be formed into one of a variety of shapes. A preferred shape is that of an annulus substantially coextensive with the ends of the concentric tubes. Preferably the ends of the fiber bundle are optically polished to provide better light dissemination, and a protective lens may be placed over each polished end of the bundle, if desired. Using an annular distal contiguration, light is transmitted through the bundle to provide high intensity, cold illumination in an annular pattern at the distal end, permitting ready observation of internal areas. Furthermore, optical fibers when cut on an angle act like a prism, refracting light in relation to the degree of the angle. It is desirable to cut the angle at a degree that produces the maximum illumination through the entire field of the telescope.

High intensity illumination is possible using the present invention. intensities up to 2000 foot candles or more at a working distance of one-half inch and up to 400 foot candles or more at four inches may be obtained by connecting the device to a fiber optic light source by means of a fiber optic light carrying bundle.

Other features of the present invention are the elimination of ,Wires and the elimination of rotating contacts on the instruments which were necessary in prior art instruments in order to provide electrical connections for the internal lamp circuit. A particular advantage of the present invention is the adaptability of the instrument to small size.

Rigid endoscopes having annularly disposed fiber optics may be prepared by the following procedure. First, using the method described in the application of Lawrence E. Curtiss, Serial No. 76,868, filed December 19, 1960, continuous strands of fiber optics are wound on a Mylar (polyethylene terephthalate) sheet which is disposed around a drum. As each successive layer of fibers is laid on the drum, a layer of thermosetting resin is plactd upon them. The resin is allowed to dry but is not cured; thus it remains tacky but does not become hard and stiff. The sheet is then cut parallel to the axis of the cylinder, and a flat sheet of Mylar having Well oriented fibers is obtained.

Second, the inner tube of the endoscope is brought into contact with the flat sheet, and the flat sheet is rolled onto the inner tube in an even number of revolutions sufficient to produce the thickness of the annular bundle that is desired. Because the resin that was applied is tacky, the sheets sticks readily to the tube, and successive convolutions stick to each other.

Third, the inner tube and optic bundle are inserted into the outer tube which is shorter than the inner .tube and the fibers used. The distal ends of the fibers are coextensive With the distal ends of both inner and outer tubes. The proximal ends are formed into a rod by pulling the fibers together. If necessary a solvent may be used to soften the resin. After forming, the rod is inserted through a terminal fitting which supports it, and epoxy resin is added to the rod end and also to the annular distal end. Finally the entire assembly is baked to cure the resin and produce a hard, rigid endoscopic tube.

Where the inner and outer tubes are made of metal or other bendable material and a bend is to be produced in the tube, the fibers may be inserted as above and the -bend made after the outer tube is applied, but before baking. The presence of the fibers between the two tubes aids in maintaining the tubes concentric. The resin is soft enough to permit the bundle to bend without breaking the fibers. In those embodiments in which the inner and outer tubes are comprised of metal they are further comprised of distal end portions `of insulating material.

The fiber optic resectoscope sheath may be prepared in several additional ways. Sheets of optical fibers drawn in a line may be cut and molded around a mandrel using a thermosetting resin between sheets, as described above. The distal end may be formed into an annulus, and the proximal end into a circular rod. The mandrel may then be removed, and the sheath baked. If desired the outside of the sheath may be protected by dipping in a plastic varnish. In this manner the optic fibers encased in plastic form both reinforcement for the sheath and act as light transmitters and insulation.

The preferred method of forming the resectoscope sheath is to use as a mandrel, a tube of reinforced plastic, such as linen-based Bakelite, melamine, Teflon or the like. The inner mandrel of reinforced plastic acts as an insulating cut-off when the tungsten loop disengages from the tissue. Around this tube a layer of optic fibers is formed in longitudinal fashion to produce an annulus, the proximal ends of the fibers being formed into a rod, preferably cylindrical, and fastened to adapt to connection with a fiber optic light transmitting bundle. The layer of fibers is then covered with an outer tube of thin metal to about an inch from the distal end of the sheath, the distal por-tion of the outer tube being made up of an insulating material, such as a plastic tube. The entire lassembly is packed with resin to form a homogeneous mass. The distal end of the sheath may be cut on a slight angle, if desired, as an aid in illumination of the internal orifice. The resectoscope sheath when connected to a fiber optic bundle produces '0 foot candles of illumination at its distal end, compared to the 1.5 foot candles produced in previous instruments. Colored motion picture photography is thus possible through the use of this instrument because of the intense illumination.

Electro-surgical instruments for use in the examination and treatment of protrusions or tumorous growths in body passages and cavities conventionally include four major assemblies: (a) an elongated external sheath adapted to form a fenestra at its distal end while being adapted at its proximal end to be connected to (b) a working element having elongated guides adapted for insertion within the sheath and to receive (c) a telescope and (d) an electrode assembly.

The distal end of the electrode is covered by an insulating shield defining an elongated passage through which the distal end of the optical system extends. With the electrode in its fully retracted position the operating end of the electrode, as well as the insulating shield, is fully withdrawn into the open end of the sheath leaving the relatively small diameter, objective end of the telescope entirely unobstructed. Similarly, the annular configuration of the light bundle at the distal end lessens interference with the telescope.

Referring now to the drawings in detail, the sheath 10 of electro-surgical instrument 12 comprises outer tubular member 14 and inner tubular member 16 defining annulus 18 therewith. In the embodiment illustrated the outer tubular member 14 is comprised of metal and has a distal portion 15 comprised of insulating material such as linen-based Bakelite, melamine, Teflon, etc. Sheath 10 terminates at its distal end 20 in a smoothly rounded end wall defining a fenestra 21 forming the end of internal passage 2. Optic fibers 24 are disposed within annulus 18 and are substantially coextensive with the distal ends of outer tubular member 14 and inner tubular member 16. Distal end portion 26 of the optic fibers is formed into an annulus. The proximal ends of optic fibers 24 are formed into a substantially circular rod 28 for connection to an external source of light as will be described below.

At its proximal end, sheath 10 is joined in liquid-tight relation to an annular mounting member 30 provided with an annular land 32, as is best shown in FIGURE 6, the inner diameter of which is substantially equal to the inner diameter of inner tubular member 16. Proximally of land 32, the inner surface 34 of mounting member 30 is tapered so that the cavity formed thereby has a diameter which increases from left to right as viewed in FIGURES 1 and 6. Collar 36 is threadably connected to the proximal end portion of mounting member 30 and engirdles the portion of the sheath immediately adjacent member 30. Mounting member 30 also carries an inlet conduit 38, the interior of which communicates with passage 22 through an opening formed adjacent the proximal end of sheath 10 for the transmission of .an irrigating liquid through the interior of the sheath and into the body cavity. Jack 40 is connected to mounting member 30 and supports rod 28, the proximal end portion of optic fibers 24. J ack 40 contains recess 42 for receiving a spring (not shown) which aids in removably connecting a flexible optic fiber light carrier to jack 40.

As shown in FIGURE 1, the working element assembly comprises an annular block 44 having an outer surface 46 which is tapered to fit inner surface 34 of mounting member 30. Fork 48 is pivotally connected by bolt 5t) to annular block 44. Pin 52 is fixedly connected to fork 48. Winged connector 54 is rotatably connected to mounting member 30 by screw 56 `and is yieldably urged toward mounting member 30 by spring 58. As best shown in FIGURES l and 5, winged connector 54 coacts with pin 52 on fork 48 to hold mounting member 30 and annular block 44 in abutting connection. Thus,

when sheath is to be removed from the assembled endoscope, winged connector 54 need merely be turned through 90 to release the assembly, and the sheath may be pulled free from the remainder of the instrument.

As best shown in FIGURE 3, annular block 44 has two passages 60 and 62 formed therethrough, and a third blind passage 64 opening through the distal wall thereof and communicating with cross passage 66. Outlet conduit 68 is atlixed to annular block 44 and communicates through cross passage 66 with passage 64. Outlet conduit 68 is provided with valve 70 for controlling the ow of uid and may be utilized to control the quantity of iluid in the part of the body undergoing examination or treatment.

Rack 72 is secured at one end to block 44 and at its other end to a support arm 74 provided with a clamp, not shown, and a clamping screw 78 to receive and secure a mounting collar 80 and aligning pin 82 of surgical telescope 84. Telescope 84 comprises a tubular stem 86 which contains a lens system including an objective lens 88 and a lens system (not shown) of any suitable type such as, for example, the lens system set forth in Patent Number 1,680,490 issued August 14, 1928. When mounted as shown in the drawings, telescope 84 is positioned with its stem 86 extending through passage 60 in mounting block 44 and along elongated guide sleeve 90, the latter being connected to block 44 with its passage in registration with passage 60. The distal end of the telescope including objective lens 88 extends beyond the distal end of guide sleeve 90. The telescope contains an eye-piece in its proximal end portion.

Also carried by mounting block 44 is elongated tube 92, which functions as a return conduit for irrigating uid, and a second guide sleeve 94, somewhat smaller in cross-section than sleeve 90, which serves to support and guide an electrode assembly to be described.

A housing 96 is slidably mounted on rack 72 and contains a pinion (not shown) in mesh with rack 72 and rotatable with a shaft (not shown) to which operating crank 98 is connected. Block 100 of suitable insulating material is carried by housing 96 and accommodates binding post 102 for receiving a suitable single-prong electric plug 104 adapted to be connected to a source, not shown, of high frequency cutting and coagulating currents. Binding post 102 is connected to a conductive core 106 provided with an opening 108 adapted to receive the end portion of electrode rod 110 forming part of the electrode assembly. Housing 96 and block 100 have passages formed therethrough in registration with one another and aligned to receive stem 86 so that housing 96, when displaced along rack 72, may slide along Stem 86.

The electrode assembly comprises the aforementioned electrode rod 110 which is an elongated, solid, metallic, conductive member provided with insulative covering 112 and extending through tubular member 114, the latter being engaged by a releasable clamp 116 having an adjusting screw (not shown) when the exposed end portion of rod 110 is seated in core 106. The distal end of electrode rod 110 merges with a pair of distally and upwardly divergent conductive arms 118 coated with insulating material, one of which is shown in FIGURE l, and terminating in a generally transverse uninsulated conductive operating electrode 120. Arms 118 are enclosed and bridged by an insulative insert 122 (FIGURE 4) forming a fenestra 124 through which telescope stem 86 extends. Electrode rod 110, being engaged with housing 96 through its engagement with core 106 and clamp 116, is reciprocated relative to sheath 10 when crank 98 is rotated to shift housing 96 along rack 72.

With the parts assembled as shown, it is apparent that housing 96 may be advanced or retracted along rack 72 and, by reason of its connection thereto, the electrode assembly is similarly advanced and retracted. In its retracted position, as shown in FIGURE 1, the

electrode and insulative insert 122 forming the fenestra are fully withdrawn into sheath 10 leaving objective lens 88 exposed. Due to the rotatable coupling provided between annular block 44 and mounting member 30, both the telescope and the electrode assembly are freely rotatable throughout 360 while sheath 10 remains immobilized.

In carrying out a prostatic resection, the instrument may be introduced into the bladder by the use of an obturator, in well known manner, sheath 10 extending through the body passage of the patient. When it is desired to start the resection, crank 98 is rotated to properly position the electrode loop 120 which is then energized. During the resection, the bladder is distended by means of liquid introduced through conduit 33, and with outlet valve 70 open over-distention is unlikely.

FIGURE 7 shows an enlarged cross-sectional detail of a sheath produced by utilizing both inner and outer tubular members comprised of thermosetting plastic materials. When the assembly is heat-treated the inner and outer members blend and fuse with the thermosetting material surrounding the optic bers producing a unitary sheath having optic bers disposed within it. In FIG- URE 7 sheath 200 was formed of inner tube 202, outer tube 204 and optic liber bundle 206, the original de marcation between pairs of layers being indicated by the dashed lines. After heattreating the thermosetting plastic materials fused into the unitary structure of sheath 200 having optic fibers 288 disposed within it.

The terms and expressions which have been employed are used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the invention claimed. For instance, the reverse cut fenestra 21 has been illustrated because of the unusually even illumination which results from the conguration, rendering it especially suitable for making motion pictures of the internal orice. However, other fenestra configurations, such as the standard cut, the forward cut, short beak, long beak, etc., may be used.

What is claimed is:

1. An electrosurgical instrument, comprising an elongated endoscopic sheath having a proximal and a distal end, said endoscopic sheath further comprising an outer tube, an inner tube dening an annular space therewith, a plurality of optic fibers disposed in said annular space, the distal ends of said optic bers being substantially coextensive with the distal ends of said inner and outer tubes, the proximal ends of said fibers extending beyond the proximal end of said sheath and being adapted for connection to a light source, said fibers throughout their extent being adhered together and substantially rigid; an electrode assembly including a conductive rod adapted to be connected to a source of electric current and having an operating loop at its forward end; mounting means supporting said electrode assembly and adapted for reciprocating said electrode assembly relative to said sheath between a proximal and a distal position; a telescope assembly connected to said mounting means and extending through said sheath; and means releasably connecting said mounting means to the rearward end of said sheath.

2. A electro-surgical instrument as in claim 1 wherein said outer tube and said inner tube are formed of resin.

3. An endoscopic instrument as in claim 1 wherein said inner tube of said sheath, comprises an insulating reinforced plastic and said outer tube, comprises plastic at the distal end portion, the remainder being metal.

4. An endoscopic instrument as in claim 1 wherein said inner and outer tubes are comprised of metal having distal end portions of insulating material.

5. An electro-surgical instrument, comprising an elongated endoscopic sheath havi-ng a distal end and a proximal end, releasable latching means connected to the proximal end of said sheath, an electrode rod reciprocable in said sheath having a distal position and a proximal position, said electrode rod in its distal position extending beyond the distal end of said sheath, means adapted to connect said electrode rod to a source of electric current, and mounting means supporting said electrode rod and adapted for reciprocating said electrode rod relative to said sheath, said endoscopic sheath further comprising an outer tube, an inner tube defining an annular space therewith, and a plurality of optic fibers disposed within said annular space, the distal ends of said fibers being substantially coextensive with the distal end of said sheath, the proximal ends of said fibers extending beyond the proximal end of said sheath and being adapted for coupling to au external light source, said fibers throughout their extent being adhered together and substantially rigid, whereby an internal light may be delivered at the distal end of said optic fibers.

6. An endoscopic sheath comprising a plurality of optic fibers disposed in a substantially hollow cylindrical array, said optic fibers being gathered at one end into a substantially circular rod oriented at an angle to said cylindrical array, a thermosetting material surrounding said optic fibers and being processed to render the optic fibers substantially rigid whereby they may be inserted into an internal orifice without further support, said thermosetting material forming an external surface of said sheath, a mounting member connected t0 said optic fibers adjacent said one end for connecting said sheath to an endoscope, and a jack connected to said mounting member, said jack supporting said fiber optic rod and adapting said rod for connection to a source of light, whereby light may be transmitted from said rod end to said other end of said sheath.

References Cited bythe Examiner UNITED STATES PATENTS 2,545,865 3/1951 Wallace 12S-303.15 2,888,017 5/1959 Wallace 12S-303.15 3,089,484 5/1963 Hett 128--6 3,146,775 9/1964 Moore et al. 12S-6 RICHARD A. GAUDET, Primary Examiner.

DALTON L. TRULUCK, Examiner.

Claims (1)

1. AN ELECTRO-SURGICAL INSTRUMENT, COMPRISING AN ELONGATED ENDOSCOPIC SHEATH HAVING A PROXIMAL AND A DISTAL END, SAID ENDOSCOPIC SHEATH FURTHER COMPRISING AN OUTER TUBE, AN INNER TUBE DEFINING AN ANNULAR SPACE THEREWITH, A PLURALITY OF OPTIC FIBERS DISPOSED IN SAID ANNULAR SPACE, THE DISTAL ENDS OF SAID OPTIC FIBERS BEING SUBSTANTIALLY COEXTENSIVE WITH THE DISTAL ENDS OF SAID INNER AND OUTER TUBES, THE PROXIMAL ENDS OF SAID FIBERS EXTENDING BEYOND THE PROXIMAL END OF SAID SHEATH AND BEING ADAPTED FOR CONNECTION TO A LIGHT SOURCE, SAID FIBERS THROUGHOUT THEIR EXTENT BEING ADHERED TOGETHER AND SUBSTANTIALLY RIGID; AN ELECTRODE ASSEMBLY INCLUDING A CONDUCTIVE ROD ADAPTED TO BE CONNECTED TO A SOURCE OF ELECTRIC CURRENT AND HAVING AN OPERATING LOOP AT ITS FORWARD END; MOUNTING MEANS SUPPORTING SAID ELECTRODE ASSEMBLY AND ADAPTED FOR RECIPROCATING SAID ELECTRODE ASSEMBLY RELATIVE TO SAID SHEATH BETWEEN A PROXIMAL AND A DISTAL POSITION; A TELESCOPE ASSEMBLY CONNECTED TO SAID MOUNTING MEANS AND EXTENDING THROUGH SAID SHEATH; AND MEANS RELEASABLY CONNECTING SAID MOUNTING MEANS TO THE REARWARD END OF SAID SHEATH.

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