Electric surgical instrument

Abstract

An electric surgical instrument includes a pair of laterally spaced, hollow tubes the distal ends of which are interconnected by a transverse electrical insulating member upon which are helically wound a pair of spaced electrodes having electrical conductors which extend through the tubes for connection to a source of high frequency current. This assembly is adapted for use with an endoscope or other similar type of instrument.

Description

BACKGROUND OF THE INVENTION

This invention relates to surgical instruments, and more particularly to a surgical operating instrument for electric cutting by means of high frequency current, particularly in the bladder.

Operating instruments of this type presently known are constructed as unipolar operating members, i.e. the instrument has an operating member which as only one electrode (e.g. German Gebrauchsmuster 1,980,836). However, the patient must be brought into contact with a so-called inactive plate-like electrode. As a result, the complete body of the patient serves as a conductor for the high frequency current whilst the loop-like electrode of the instrument, which is for example mounted in an endoscope, is constructed as the active electrode by means of which the cuts for removing diseased tissue are performed. For this purpose the current potentials must be comparatively high because on the one hand the whole body of the patient serves as a conductor and on the other hand sparking must occur on the loop-like active electrode. It is possible for burns to occur at the inactive electrode if contact with the patient's body has not been completely satisfactory.

In order to avoid the foregoing disadvantages of unipolar operation in hemostatic coagulation, bipolar coagulation recently has been used in surgical operations. For this purpose, high frequency current is supplied to each of the two legs of the forceps which are insulated relative to one another. The tissue between the legs of the forceps is coagulated as soon as these legs are at the necessary limited distance from one another. As a result of such bipolar operation, the advantage obtained is that the high frequency current can be a multiple smaller than with unipolar operation. Accordingly, the danger of burns is eliminated.

However, operating instruments for use with endoscopes and other similar instruments heretofore have not been provided with a pair of electrodes for bipolar operation in such organs as the bladder.

SUMMARY OF THE INVENTION

In its basic concept, this invention provides an electric surgical instrument which may be used with endoscopes and similar instruments for bladder and other operations, wherein the instrument is provided with a pair of electrodes.

It is by virtue of the foregoing basic concept that the principal objective of this invention is achieved; namely, to overcome the aforementioned disadvantages of prior electric surgical instrument for these types of operations.

Another object of this invention is to provide an electric surgical instrument of the class described in which the pair of electrodes are maintained in accurate spaced-apart arrangement.

A further object of this invention is the provision of an electric surgical instrument of the class described in which the support for the electrodes may be shaped to accommodate use with endoscopes and other similar types of instruments.

Still another object of this invention is the provision of an electric surgical instrument of the class described in which the pair of electrodes are supported to provide maximum surface areas facing one another.

A still further object of this invention is the provision of an electric surgical instrument of the class described which is of simplified construction for economical manufacture, which is capable of being cleaned with speed and facility and which is operable with precision and maximum safety.

The foregoing and other objects and advantages of this invention will appear from the following detailed description, taken in connection with the accompanying drawings of preferred embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a foreshortened front view, partly in section, of an endoscope having associated therewith an electric surgical instrument embodying the features of this invention.

FIG. 2 is a foreshortened side view of the electrical surgical instrument shown in FIG. 1.

FIG. 3 is a view in transverse section taken on the line III--III in FIG. 2 on a greatly increased scale.

FIG. 4 is a transverse sectional view of an electrode support in a further embodiment.

FIG. 5 is a fragmentary section taken in the longitudinal direction through the electrode support of FIG. 3.

FIG. 6 is a fragmentary plan view of a lathe tool for producing the electrode support of FIGS. 3 and 5.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows an endoscope shaft 16 in which is arranged the viewing tube with the eyepiece 18 and the lens 13. This can be of conventional design and is known to those skilled in the art. The electrode support carrier, commonly known as a loop carrier, and the appropriate guide block 17 also are fundamentally known.

The viewing tube is non-displaceably but interchangeably connected with the endoscope shaft 16 and a considerable portion of its length projects above the head 19 of the endoscope shaft. In the area of eyepiece 18 is articulated a lever 20 whose free end is hinged in shear-like manner with arm 21 of a hand lever 22 which, in turn, is articulated to guide block 17 and is constructed in the form of a control handle 23. Upon operating hand lever 22, relative to the attachment 24 on the eyepiece, the guide block 17 is moved in the longitudinal direction of the viewing tube.

The loop carrier comprises two parallel tubular rods 10 and 11 which are interconnected and guided on the viewing tube 15 and which at their distal ends carry and are interconnected by a transverse electrode support 12. In the embodiment illustrated, this support is in the form of an open loop (FIG. 3).

According to the invention, the left hand tubular rod 11 contains an insulated electrode wire 1 and the right hand rod 10 contains an insulated electrode wire 2.

In the area of the distal end of the viewing tube 15, the loop carrier is provided with a guidance member 14 in the form of a sleeve which surrounds the viewing tube and is supported on the inner wall of the endoscope shaft 16. The remaining inner area within the endoscope shaft serves as a washing passage. Guidance member 14 is provided with a nozzle-like constriction 24 (FIG. 2) through which a washing agent can be sprayed onto the loop 12 in order to clean the same. In head 19 of endoscope 16 is provided a pair of pipe connections, one being provided with a tap 26, the other with a tap 28, for the supply and discharge of the washing agent.

The insulated electrode wires 1 and 2, which are not shown in FIGS. 1 and 2 and which are for example 0.5 mm. thick, are located in tubes 10 and 11 and terminate at the top in plug 25 for connection to a source of high frequency current, not shown.

FIG. 3 shows a preferred embodiment of electrode support loop 12 on a greatly enlarged scale. It is curved according to the internal diameter of the endoscope shaft 16. The loop is made of electrical insulating material 4, preferably synthetic thermoplastic resin having appropriate strength and elasticity. Such plastics are well known to those skilled in the art. The support must be constructed in such a way that maximum surface areas of the two electrodes 1 and 2 face one another across the predetermined limited spacing between them. This means that particularly between the closest points of the two electrodes there will be no insulating material, because here the cutting process according to this invention takes place by spark-over.

Referring particularly to FIG. 5 of the drawing, which shows FIG. 3 on a greatly enlarged scale, the insulating support 12 is provided externally with two parallel helical threads 5 and 6 which are of the same pitch and which are axially spaced relative to one another by a desired limited spacing. In this way, the two electrodes, whose diameter, for example, may be 0.5 mm., can be reliably kept at the desired limited spacing a from one another in the two parallel threads so that most of the surface thereof projects outward above the threads. As a result, the length of the electrodes which are in this way distributed over the loop is much greater than that of the loop itself, so that the total cutting surface is increased. The diameter of the insulator 4 is also kept small and can be, for example, 1 mm. It is particularly preferred that the limited spacing between the two electrodes be half as large as the pitch of the threads. In this way, a uniform construction of the threads over the insulator length is achieved.

The uninsulated portions of the electrodes 1 and 2 are wound onto the two parallel threads 5 and 6 of insulator 4 in the manner clearly shown in FIG. 5. Therefore, the left hand electrode 1 terminates at the right hand end of the insulator adjacent tube 10 and, conversely, the right hand electrode 2 terminates at the left hand end of the insulator adjacent tube 11.

The diameter d of insulator 4 can be, for example, 1 mm., whilst the diameter of electrode wires 1 and 2 can be, for example, 0.5 mm. The two parallel threads 5 and 6 have the same pitch h because otherwise the threads would run into one an other. The axial spacing a thereof relative to one another corresponds to the desired limited spacing between electrodes 1 and 2. This relates to the centers of the electrode wires. As can be seen, the closest points of the electrode surfaces are much closer together. In this way, very limited spacings of electrodes 1 and 2 can be reliably obtained because the electrode wires are securely held in threads 5 and 6 and cannot become displaced.

FIG. 5 only shows a short portion of loop 12 which, according to FIG. 3 is at least partly curved, corresponding to the inner diameter of endoscope shaft 16. The insulating plastic material from which insulator 4 is made has the necessary strength, but at least when warm can be brought into the form of FIG. 3. Insulator 4 not only has the function of keeping the thin electrode wires 1 and 2 at a particular spacing relative to one another and insulating the same relative to one another, but also insures the necessary stability of the structure. In this connection, wires 1 and 2 can be considerably thinner, for example 0.1 mm. thick. As a result, a good cut is insured and also a high degree of stability in the case of clamp cuts, gripping pieces of tissue and currentless shaving.

In FIG. 5, the two threads 5 and 6 preferably are constructed as buttress threads, in order to leave freely exposed the maximum portion of electrode wires 1 and 2.

The threads 5 and 6 can be produced by conventional means. In accordance with this invention there is provided a recessing lathe tool having two cutting tips spaced apart relative to one another by the desired limited spacing corresponding to the cross section of the two threads. By means of this lathe tool, the indicated construction of the threads can be obtained in simple manner by turning the insulator 4.

FIG. 6 shows a lathe tool 7 which can be used to cut threads 5 and 6 in insulator 4 according to FIG. 5. This takes place on a small lathe, such as is conventionally used in the watch industry. A feed of h=2a must be selected to give a completely uniform arrangement of the two separate threads 5 and 6 for receiving the two electrode wires 1 and 2. To this end, the two cutting tips 8 and 9 must be at the spacing a from one another and contoured to produce the desired shape of threads.

Although the electrode support 12 of FIGS. 3 and 5 is circular in cross section, it may have various other cross sectional shapes. For example, it may be fork-shaped in cross section, as illustrated in FIG. 4. This embodiment keeps the two electrodes 1 and 2 at a distance a and partly surrounds the same, but leaves free for sparking the area where the two electrodes 1 and 2 are closest together. Insulator 3 and electrodes 1 and 2 therefore together form a loop 12 as in the embodiment according to FIG. 3.

Whatever shape is selected for the insulators 3 and 4, it is important that the electrodes 1 and 2 be kept at the desired limited spacing a from one another by the insulator, in order to achieve efficient bipolar cutting.

It will be apparent to those skilled in the art that various changes may be made in the size, shape, type, number and arrangement of parts described hereinbefore, without departing from the spirit of this invention.

Claims

Having now described my invention and the manner in which it may be used, I claim:

1. An electric surgical instrument, comprising:

a. a pair of elongated, laterally spaced and substantially parallel hollow tubes,

b. an electrode support of electrically non-conductive material secured to and extending transversely between the tubes at one end thereof,

c. a pair of electrodes mounted upon the electrode support in spaced-apart relation and extending transversely between the tubes, and

d. an electrical conductor connected to each electrode and extending through one of said tubes for connection to a source of high frequency current.

2. The electric surgical instrument of claim 1 wherein the electrode support has a pair of helical threads of equal pitch spaced apart a predetermined distance and each mounting one of the pair of electrodes, with a substantial portion of the cross sectional thickness of the electrodes projecting outwardly from the threads.

3. The electric surgical instrument of claim 2 wherein the predetermined distance between the electrodes is substantially one-half the pitch of the threads.

4. The electric surgical instrument of claim 1 in combination with an endoscope having a hollow shaft, wherein the electrode support is curved to correspond with the internal diameter of the endoscope shaft, the tubes and electrode support being mounted within the hollow shaft.