US1995526A - Electrosurgical apparatus - Google Patents

Description

March 26, 1935. F c, WAPPLER I l 1,995,526

Y ELEGTROSUR'GICAL APPARATUS Filed sept. 27, 1932 Patented Mar. 26, 1935 e. insee-,5cc Vf; v 'ELEctraosURGloAnAPBARATUS mrfeaenfck. charlesgwapler; YNewvaleria. Y. V ...Application september 27,r leaalserial No.1634,992

' ,-f-aolaims. (cil-1744+177) L My presenti.inventionrrelatesf general-ly toi the .electrosurgical tart;aazdhasf`lparticular-'reference to Ianew andimprovedimethodzandaapparatus for streatingzbodyctissue cor thezlikefwith highfre- Sa'quencycurrents. ,-5

.While the charactem'sticsi and capabilities vof yhigh-frequency..alternatingcurrentswvith respect :l to Atheir eects uponzthe' .body tissue; .are 'not f as yet fully or, thoroughly understood :by ythose l0 L skilled in the Earn-.certain unique abilities `of .lligh-frequen'cy currents,l-When properly-' gener- '..ated andapplied to thebcdy;y are-oi denite and rrecognized J eectiveness in Vuqzuerformirlg 'various surgical operations. Apart f'romthe purely heatl 5 .generating wpowers of 1 such currents, the gpl-of fessionis steadily coming. to lookwi-th more and amore. favor andgapproval liponA ythe two types of phenomena i generally f refer-red to a as cutting "and coagulation. .20 ;'It is generally. perceived-thatza cuttingef ect is usually vbest accomplished by-means of.an at tenuated type of electrode; that the-effect israecompanied by more =or less violent sparking; vand that in all-'probability the results achieved are due. to extreme concentrationfcf. yhigh-fre- `quency current.- fThe so-called coagulationef- .fect is ygenerally looked .upon-as 'ajmilder 'case of -the same phenomenon,'but Whether this isso at `least open to` question. The' eiectis usuallyproducedy with relativelyj' blunted instruments for electrodes; it has been Aheretofore-often `accompanied' by a degree ofsparkingc and itlproduces -a sort of penetrative desiccationof tissuewhich -isl less than asearorburnaand Whichfis akin cooked. y

:It is desirable to -havebothfof these vphenomena available and-.underl control during ,almost --any operation. `AWhile a certainV amount of.- coagula- 40 tion isfeffected by-a cutting-electrode..duringna "cutting procedure, an electrode usually I thought of n as primarily delivering a cutting current or a coagulating' current;: and where `a cutting electrode vis'fsought tobe used vforga Jcoagulation .-effect, it- :has-r been customary heretoyfore to modify thecurrent Vdeliveredfby it whenever theeifect- :desired is primarilyI coagulative 'in-:characten 1 It/is thereforeV noty surprising to-.find thata number... of attemptsv have heretofore been `made, and sometimes successfullm,v to provide-a means for quickly and eifectivelyaltering the characteristicstof current fed to,an-electrodetopermit theyoperator `to nuseca .single f electrode, .at- ,.will, foreither cutting orcoagula'tion.

tov the change-which tissue-undergoes. when it is @It hasbeemfound: satisfactory, `for example, to interposean impedance,at.Lvvill,y into: series f-.with the cutting e1ectrode. While this permitsl;the. electrode='tovbe usedfafter-.a'fashion, as a vcoagulating;tool,itiis obvious that this typey of 5 arrangement.isessentia1lya1-wastefu1 and inei- :cientone; .-Sornetimes,wthednputgpovver to thev oscillatingccr tankcircuit of the high-frequency ggeneratorcrhas beenfreduced to Apermit an` electrede,usedprimarily?for,cutting, -to be lutilized ,at will. as ay coagulating 4lr`vtool. In other instances, apparatus Y 'has-:been devised for com pletely raltering theccharacteristics of: .the :oscillating ori tank circuit and for simplifying the A facility-. With lvvhichsuchr Ya complete changeover 15 A can be accomplished by the operator. j

Circuits have also been devised, las, for-example, :in the "Bauer Patent No. l,645,215,j taper-mit afgcutting, procedure` tobe. effected.v with one adjustment of the apparatus, and accoagulating .20

. procedure to .bef effected at.v another portion ofl theyL apparatus andV` by. makingA various adjustments therein. A Y f f So far as Lani .aWare,r nobodychasever hitherto.beenksuccessful-indevising an. apparatus or rnethod wherebyl acutting electrode anda coagulating electrode could` be siniultan-:ously utilized in association .with a'single.generatingapparatus; andit` isa generalA object .of my .pr'esentlvinvention.. toiprovidevxa fncethodend apparatusof this 30 character. i

Sta-ted, otherwise, .it .an objectof my present invention .to `provide .al method and. apparatus Wherebyraoljustrnents ,of the generating .apparatus,. either-byjnterpositionTor. withdrawal-of irn-4 3 .vpedances, reductionplor' modica-tion .of Ainput .poweralterations inessen'tial characteristics, or .other inodications of hookuploroperation, are 4utterly'5u'lineces's'ary and are dispensed with, While', cuttingandcoagulating effects in ay .neverthelesslbe .siinultaneouslycapable of accomplishment. .The. advantages lachieved .Will, ofcourse, be obvious.tolthseskilled in the art. `j yStability and, sirifli'licityv of .operation are.. enhanced substantial.. economies inffmanufacture .are-effected; .5

r'naniiJulatins`r and. adjustments by a surgeon, usu'ally. not'. 'thorou'ghly. familiarwith.v electrical phenomena andapparatus, are rendered unnec- .essary;,.andl the operative procedurestheniselves are caused to be. simpler','."r'nor'eleflicientl andsafen .50 With afsingle apparatusl offy.preseiihv char'- acter,' .it.is` ..possible`, yfor!example, forla surgeon to Wie1d;;a cutting.. electrode .while "his .assistant r rnayc at-ithesairie tine wield thecoagulating .elecl `trof'de'and."thereltiy`A eifectihemostasis at the point 55 or points required, as the main operation proceeds. Similarly, a single tool may be feasibly provided with two operative heads or electrodes thereon, one beingprimarily and continually a cutting tool, while the other is simultaneously and continually available as a coagulating tool.

A particular feature of my invention lies in providing an apparatus which permits these desirable effects to be accomplished without impairment of the t stability or efficiency of either the cuttingor the coagulating. So far as I am aware,

all previous attempts simultaneously to produce these two effects from a single apparatus have been uniformly unsuccessful; the drainage of current from a coagulating electrode has always seemed to impair the current'fed frorrrthe cut-I ting electrode, and vice versa, as a result of which the cutting electrode has been' caused to balk or sputter, the coagulating electrode has been 4seriously slowed up in its effect, and neither electrode has served-tofaccomplishits desired effect with any sort of satisfactory efficiency.

My invention is predicated upon a thorough there is a critical locality of intermediate potential in anoscillating or tankA circuit Aat'which optimum coagulation may be effected without in the least impairing or interfering with the stability or eiiciencyof optimum cuttingwithin.v the cutting range.v v 'Y Iachieve the foregoing 4objects-and such other objects as may hereinafter appear or be pointed out, inthe manner illustratively exemplified in the accompanying drawing, wherein- Y Y Figure `1 is `a diagrammatic representation of 'an electrosurgical apparatus embodying the featuresfof my present invention; ,and y Figure 2 is a graphdepictingthe characteristics which I have found to exist in an oscillating circuit of an apparatus of the present character. i

So far as my investigations have thus far indicated, any convenientor suitable vtype vof generator of high-frequency oscillationsmay beemployed in an apparatus `of the presentfcharac'- ter. Essentially, such a generator will comprise an output oscillating or tank circuit 10 in which an inductanceY coil 11 and a capacitance 12 are A-arranged in parallel. Such 'tank circuit isr connected to any suitable type of exciting circuit,

which 'I have diagrammatically indicated by the reference numeral` 13. The exciting circuit ob- `ftains its power from a suitable powersupply 14.

\ `It will Vbe understood that my present invention 4is notilimt'ed to any specific type of highfrequencygenerator, except in so far as such a generator is provided with an output oscillating circuit of the character vindicated at 10. For exampl e,"' an" electrical arrangement of parts ofthe fcharacterjshown in'my copending application 4Serial Number581,908 hasjproven satisfactoryfor A,my fpresent purposes.A In this type .of generator, the exciting' circuit,y comprisesa S-element vacjuumtubeftogethcr with suchother electrical apparatus,` transformers, chokes,and"the like `primarily and'essentially'a r Similarly, I have illustrated the yel'ectrode'ilg which are necessary or desirable for causing the exciting circuit to draw power from a suitable source of supply and feed it to the oscillating circuit to maintain the latter in a state of oscillation. In the generator described and illustrated in my aforementioned copending application, the power supply is the ordinary commercial current of low-frequency, such as 60-cycle, 110 volt, alternating current.

1 Itwill' be found that an oscillating circuit of the character designated by the reference numeral 10 will have a portion of relatively low potential and an opposite portion of relatively high potential. j In Vthe present drawing, for example, I have'shown arelatively large indifferent elecjtrodel connectedgfas at 16, to a point of relatively lowl or indifferent potential. This indifferent electrodeis not always required, but is usually and preferably provided for the purpose of establishing an electrical contact with the body to be treated. I have shown a cutting electrode .'17 'connected-to .the oscillating circuit, as at 18, which: is at a pointV of relatively high potential.

It will be understood that the exact difference in potential between the point 18 vand the point 16 is'very difficult. to ascertain by ordinary current-measuring instruments because of the nature of the high-frequency alternating current which flows Vthrough the;"oscillating circuit l0. It will also be understood that the voltageat the point l'isnot necessarily a very; high voltage, in the ordinary sense ofthis term, .and is, in

fact,relatively low with respect to the magnitudes `of voltages'which are customarily available and utiliZedin-the' electrical art at the present time. f

The fact-is, however, that the point 18 kis at a relatively high potential with .respect to the point 16; and that between thesepoints, the oscillating circuitr will be found to be impressed with aA range of intermediate potentials increasing gradually from the point' 16 to the point 18;-

In accordance'withv my present invention, a coagulating electrode 19 is connected to theY oscillating vcircuit =10, as'` at 20, which is a point The locality vof conl of` intermediate potential; nection 20 is -a critical one,`as will be pointed out more clearly hereinafter, Aandv permits both electrodes 17`and 19 to `draw the necessary cur- `rents fromA the oscillating circuit l10 for the fulfillment of their respective `purposes,'without any mutual impairment of effect.

I have illustratively'sh'own the electrode k1'? with an attenuated tip or head, since this is usually the type of electrode which is utilizedv for cutting purposes. Obviously, however, any suitable tip may be provided, as, for example, a yloop orA the like, the term -cutting electrode .being intended to signify any suitable-type of electrode whosefunction is to'produce aneffectzwhich yis cutting effect."

as one which is provided with a relatively blunted or thickened head or tipfsincethis is usuallythe type of electrode employedfor effecting coagulation 'of 'tissuef It Willbe understood, however,

'that any suitable'type of electrode maybe utilized for this purpose, and that the'ternrcoagulating electrode is intended to signify an' 'electrode whose primary and essential veffect is'v to produce orcooking of tissue, 4as distindesiccation guished from cutting.`

'Ifhe successfulachievement of my general objectives and the efficient operation vof the apparatus illustrated 'inFigure'i ispredicated upon a discovery of the existence' of certain critical ranges and phenomenav which are more fully illus- -trated in a'graphicinianner in..Figure 2... The

abscissa of Figure 2 represents 'the gradientepotential existing in the oscillating circuit'between the points 16' and l18.l -.The potential at the'right of'Figure 2, for example, is relatively low'and has beenl designated by the -term low; andthexpotentialincreases gradually to theleft of Figure 2,

atwhich-theterm high has beenused to sig- ,nify a relatively high potential. The potentials at -theopposite extremes of Figure 2 may, for example, correspond to those existing at the points '1,6 and 18 of Figure l.

The. ordinates off Figure 2-representY efliciency or effectiveness ofA operation.. L Y i' The-curve 21;isindicative of the cutting :effect that maybe obtained -by the ordinary'type of relativelyfattenuated cutting electrode ,as the same isl .connected successively to' various .points of theoscillating; circuit," for ,example, various points along the coil 11. It has been generally known that arv-moresatisfactory cutting-effect is achieved in the yarea orrange of relatively high potentials,- but it may not have been fully realized that the cutting effectdoes not `diminish gradually all the way to the low potential or indifferent portion of the circuit, b ut diminishes with conlsiderablerapidity toward a point 22 below which Vrio-'cutting electwhatsoever, with even the finest electrode, may be obtained. y

At the outset, therefore, I` have clearly ascertained that inan oscillating circuitfof vthe `present general character, vthere is a definite potential range within vvhich'lno` cutting-at all may be accomplishedand an adjacent range in which'the cutting effect or efficiency gradually risesfrom a barelyperceptible one to a substantial and practically useful one. l.

Within the upper portion of this cutting range, evenblunted and bulbous electrodes produce effects which are primarily cutting effects, accompanied by a substantial amount of sparking and. outright destruction of tissue. When a relconnect a coagulating electrode to an oscillating circuit of the present character have naturally and understandably established connection between the coagulating electrode and the .oscillating circuit at a point closely adjacent to the point 24. The utilization of such a coagulating electrode, however, has invariably made it impossible simultaneously to `utilize a cutting electrode at the same time. For some reason or other, with such an arrangement, the simultaneous use of a cutting electrode and a coagulating electrode has proven to be unfeasible. Either the coagulating electrode has failed to produce its coagulative effect with satisfactory rapidity, or, more usually, the cutting electrode has been caused to sputter and balk with entirely unsatisfactory and useless results.

My experiments have led me to analyze the -stantial land remarkable .trode connected-.toV the usual high lpotential. 'entirely clearl to me, it appears that a coagulating optimum .pure ."coag-ulativev effect gis I'capable :of achievement.'v .The-curve 264 indicates .the eili- .ciency or effectiveness of coagulation withithe use of a nely attenuated electrode. Starting. at

the low or vindifferent end of the circuit,'the colagulative effect is'at first almostnegligible fand practically useless, but it increases-with considerable rapidity to the .point-.25. `Unlike the yeffect line 23-,-but actually starts to` diminish yvvithsubrapidity along theline 26. i v 'i Thepoint 25 is, therefore, aeritical.` point at which a'flnely attenuated electrode will produce anloptimum coagulative effect; and thisis .the

point atwhich the cutting :effect is first perceptible.1 .y 1 The remarkableand truly usefulv .characteristic of a connection at thefpoint 25 (or in the locality close to it) lies in the fact that coagulation may be elciently' accomplished even rwith an electrode 'ofther conventional blunted type, Without in the least i-mpairing the cutting effect of la cutting elecpoint of relatively For some reason, which is `not electrode may draw whatever currents: it may needv fromthe'locality adjacent to the point25 to produce anoptimum coagulative eifect-whichnis entirely practical and useful without inthe :least impairing the stability or efliciency.l of v.cutting eifectxproduced by -a `'cutting electrode operating simultaneously,

My present invention 'lies in harnessing. these phenomena tothe present useful purpose of providing anv apparatus in Whichcoagulation and cutting may be'simultaneously effected Afrom a single high-frequenecy. generator; and the point of connection 20 indicatedin Figure lxisintended to signify the locality `adjacent to the point designated `by the; referencejnumerals. 22 andr25 in ly necessary' to employ a nely attenuated electrode vand t'o'vconnect it successively to ,various points withinthe low potential range of the circuit. At'a certain point of connection,indicated by thereference numeral 22 of Figure 2, sparking will suddenly manifest itself, and this point is capableof veasy and" definite vdetermination by .coagulative effects of anextremelyne electrode, :and as a .resultI have madel the surprising dis- -covery that the'point24 is onlyva. 'false orfapaparent; point.= of .optimum coagulative; effect; and fthat the; point 25 islthe critical point at which y.5o Figure 2. In ascertaining this locality, it is merethis method. It isv thereupon a simple matter to establish the desired electrical connection with the conventional type of coagulating electrode, and in practice the manufacturer will in all probability connect a tap or binding post tothe point 20, so that the surgeon will ultimately be required to do nothing more than connect his coagulating electrode to this tap or binding post.

Stated otherwise, I have lfound that if a coagulating electrode is connected to the circuit at a point of potentialsubstantially higher than the critical point 20, the efficiency at the cutting electrode will be seriously impaired, and either one or the other electrode will have to be used singly.

On the other hand, if the coagulating electrode is connected closely adjacent to the upper limit of the low potential range at which no sparking .occurs with even' a `finely, attenuated/electrode,

the efliciency at the cutting electroderremains entirely unimpaired. Obvious1y,. it may be de- :sirable to connect the coagulating electrode to a point slightly above the upper end of the low potential range last referred to, but care' must be takento prevent the connection` frombeing made lat a.-v point of' substantially higher potential than this. i

vAlthough I have found it preferable in practice to makel the connections-of the electrodes to respective points along the inductance coily l1, nevertheless it will be understood that' the connections might be made with equal facility to the capacitance side of the oscillating circuit, but in `such an eventthe condenser 12 would have to'be subdividedinto a largefnumber of: separateunits arranged inseries, since it is obviously impossible to locate and make a connection to a lcriticalpotential which might, for example,'lie withinthe dielectric of any given condenser.

Furthermore, it will be understood that in prac- 'tical usage, it may be desirable to provide anyone or more vof the electrodes with condensers or similarimpedances, for purposes of safeguarding the patient. For example, in the electrical apparatus illustrated in my copending application, a variableac'apacitance isarranged in series with the active electrode. Y

Other `elements of the generator, suchk as switches or`the like, have'been omitted from the present showing sin'ceth'ey have no direct bearing upon the present invention, and the desirable provision lof such auxiliary parts Will, it is believed, be readily understood by those conversant with the art.

The essential characteristic of my present invention lies in the simultaneous connection of a cutting electrode to a point of relatively high po- ,tentiaL and acoagulatingelectrode to a critical .point `of intermediate potential, whereby both electrodes may be efficiently employedsimultaneously without requiring `any adjustments, manipulations, or alterations of electrical parts or modes of operation.

In general, it will be understood that changes in the details herein described .andv illustrated for: the purpose of explaining the nature of my invention may be made by those skilled inthe art without departing from the spirit andscope of the invention as expressed in the appended claims. It is, therefore, intended that these details'be interpreted as illustrative, and not in a limiting sense.

Having thus described my invention, andvillustrated its use, what I claimjas new and desire to secure by Letters Patent isl 1. In an electrosurgical apparatusof the char'- acter described, a generator of high-frequency current including an output oscillating circuit, said circuit being impressed by said generator with a high-frequency voltage gradient, a cutting electrode connected to said circuitl at a point of relatively high potential, anda coagulating electrode connected to` said circuit adjacent to the y upperend ofthe low potential range. in which no sparking occurs with evenv a iinely` attenuated electrode, said coagulating electrodebeing thereby enabled to` dravv` 4current for optimum` pure coagulative `effect withoutv impairment of the cuttingxeffectrat the cutting electrode. 4 2. In an electrosurgical apparatus ofthe character described, a generator of high-frequency ing occurs with even anely attenuated electrode.

3. In an electrosurgical apparatus of the'character described, a generator of high-frequency current including an output oscillating circuit having an inductance -coil and a capacitancein parallel, said coil being impressedby'saidgenerator with a high-frequencyl voltage4 gradient, a cutting electrode connnected to Vsaid coiljat a Vpoint of relatively high potential, and a coagulating electrode connectedv to'said coil-'at the upper end of the low potential range in which no sparking occurs with even a iinely attenuated electrode.

FREDERICK CHARLES- WAPPLER.

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