US3532095A - Electrosurgical instrument - Google Patents

Description

United States Patent Alphonse K. Miller Merrick;

Frank P. Loiacono, Brooklyn, New York [21] Appl. No. 739,120

[22] Filed June 21,1968

[45] Patented Oct. 6, 1970 v [73] Assignee Edward Weck & Company, Inc.

Long Island City, New York a corporation of Delaware [72] Inventors [54] ELECTROSURGICAL INSTRUMENT 15 Claims, 7 Drawing Figs.

[52] U.S.Cl ..l28/303.l3, l28/303.17 [51] Int.C1 .iA61bl7/36 [50] Field ofSearch 128/303.l3 303.19; 174/46 [56] References Cited UNITED STATES PATENTS 1,394,171 10/1921 Hall 128/303.l8 3,295.514 1/1967 Hein et a1. 128/303.l4X 3,461,874 8/1969 Martinez l28/303.l 7

Primary Examiner-L. W. Trapp Attorney-Joseph Weingarten ABSTRACT: An electrosurgical instrument with interchangeable electrode tips. The electrode tips are firmly held in place in a spring biased chuck which allows the tips to be readily removed and reinserted.

Patented Oct. 6, 1970 35321695 INVENTORS' ALPHONSE K. MILLER FRAN K P LOIACONO Patented Oct. 6, 1970 Sheet 1NVENTORS ALPHONSE K. MILLER FRANK P. LOIACONO A TQ'RN ELECTROSURGICAL INSTRUMENT FIELD OF THE INVENTION This invention relates in general to surgical instruments and more particularly concerns a novel sterilizable electrosurgical instrument having interchangeable electrodes.

DISCUSSION OF THE PRIOR ART Electrosurgery is a form of surgery in which body tissue is removed or destroyed by heat generated by an alternating high-frequency current, and is accomplished by any one of three methods: electrodesiccation, electrosection, and electrocoagulation. All of these methods use an active and indifferent electrode. Using electrosection as an example, the indifferent electrode may be a large metal plate which is placed on the arm, leg or back of the patient. The active electrode may have a wide variety of shapes such as a needle for cutting or a wire loop for scraping. Tissue touched by the active electrode is disintegrated but the heat generated by the instrument does not penetrate deeply into body tissues. In this manner, the active electrode functions as a knife. A particular advantage of this type of surgery is that small blood vessels are sealed by the heat and bleeding is thereby controlled during the surgical operation.

Various instruments have been developed which are intended for use in electrosurgery. These devices disclose different means for attaching an active electrode into an insulating handle and applying electrical power thereto. The electrode in these devices is often shown adjustable in length by means of a setscrew and may be removed from the handle when the setscrew is sufficiently loosened. However, these devices do not allow for easy interchangeability of the active electrode since a setscrew must be loosened or tightened, often by means of a suitable tool such as a screwdriver.

The electrosurgical instruments which have been designed for rapid interchangeability have used several means for releasing the electrode tip from the handle. However, some of these devices have suffered from the fact that the electrode tip release may be accidentally tripped resulting in possible ejection of the electrode during surgery or at other inopportune moments. Also, many of such mechanical devices are somewhat cumbersome or are not properly balanced for close surgical use where a certain feel" is necessary for the surgeon to properly use the instrument.

SUMMARY OF THE INVENTION The novel electrosurgical pencil of this invention provides an insulative handle containing a chuck which holds the shank of an active electrode in a positive manner while allowing the electrode to be easily removed or replaced simply by pulling it outward from the end of the chuck or by inserting it into the chuck. No separate mechanical release means is required, thus eliminating the problem of accidental release. The instrument is carefully machined and balanced to ensure the feel that is so necessary in surgical operations.

Broadly speaking, the chuck employs flexible grasping fingers urged into a closed position by means of a spring which longitudinally biases the tapered flexible fingers of the chuck into a bushing within the electrode end of the handle. The active electrode shank is inserted into the end of the handle where it is firmly gripped by the chuck. An electrically insulative sleeve surrounds that portion of the shank which protrudes from the handle so that only the tip of the active electrode is exposed. The sleeve abuts a shoulder within the electrode end of the handle thereby providing a positive stop when the shank is inserted into the chuck. The opposite or connecting end of the handle is provided with an electrical receptacle which may be adapted to receive a banana plug or other suitable type connector. An electrical path from the receptacle to the electrode is provided through the chuck.

The materials of the instrument are sterilizable so that when the power is disconnected and the active electrode removed,

electrode tips may be cleaned and sterilized separately and later connected to the handle, or the handle and electrode may remain interconnected and sterilized together so that they are made ready as a unit for their next use.

BRIEF DESCRIPTION OF THE DRAWING The features and advantages of the invention will become apparent from the following detailed description when read in conjunction with the accompanying drawing, in which:

FIG. I is a perspective view of an electrosurgical instrument constructed in accordance with the principles of this invention;

FIG. 2 is an elevational view in section of the instrument of FIG. 1;

FIG. 3 is a sectional view taken through cutting plane 3-3 of FIG. 2;

FIG. 4 is a sectional view taken through cutting plane 4-4 of FIG. 2;

FIG. 5 is an enlarged sectional view of the electrode end of the instrument as shown in FIG. 2;

FIG. 5A is an enlarged sectional view of the gripping end of the chuck shown in FIG. 5-, and

FIG. 6 is an exploded view of the elements which are disposed within the handle of the instrument.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now,to the drawing,handle 11 is a substantially rigid elongated hollow tube. It is shown with a plurality of flat sides which permit it to be firmly gripped by the operating surgeon.Main bore 12 inhandle 11 extends from the connecting end (at the right in the drawing) to a point adjacent the electrode end at which end are formed smaller bores l3, l4 and 15. Bore 14 is smaller thanbores 13 and 15 and provides a neck between them formingshoulder 16 facing inward andshoulder 17 facing outward toward the electrode tip. The connecting end ofhandle 11 is formed withthreads 22 on its exterior surface.Adaptor 23 hasthreads 24 formed in the interior surface of one end thereof extending from a point near theend surrounding handle 11 toshoulder 25 which is defined by reduceddiameter bore 26, which threads mate withhandle threads 22.Counterbore 27 extends throughout the remainder ofadaptor 23. Whenadaptor 23 is screwed onto the connecting end ofhandle 11, it forms an enlarged continuation thereof.Handle 11 andadaptor 23 are both electrically insulative and may be made of a suitable sterilizable, rigid and substantially unbreakable plastic of a type well know in the an. Certain suitable plastics are sufficiently rigid to be machined, in whichcase threads 22 and 24 may be machined into their respective parts to ensure a smooth, close fit.

Turning specifically to FIG. 6, the mechanical elements within the handle and the adaptor will now be described in detail. Electrode 32 is comprised ofshank 34 which has enlargedtip 33 and smoothly rounded oppositeend 35. It should be noted that the tip of the electrode may be any desired shape as required for the particular surgical situation at hand. For enhanced electrical and surgical properties, electrode 32 will preferably be made of stainless steel. An electricallyinsulative sleeve 36 is snugly fitted overshank 34 andabuts tip 33.Sleeve 36 is made of a sterilizable plastic such as nylon or polytetrafluoroethylene and is substantially shorter thanshank 34. Its functions will be fully discussed below.

Bushing 37 is force fitted withinbore 13 ofhandle 11 and is seated againstshoulder 16 therein. This bushing may be made of any suitable material such as brass. It is, however, quite possible thatbushing 37 may be eliminated by properly shaping the interior ofhandle 11 to perform the same function.Bushing 37 is provided withbore 41. andcounterbore 42. Thetransitional surface 43 is tapered inwardly, as isedge 44 which defines the opening ofcounterbore 42.

Hollow tubing 45 is an electrically conductive member formed withelectrode gripping chuck 46 at one end and annularspring retaining groove 47 at the other.Tubing 45 is preferably made of spring steel having a coextensivelongitudinal bore 48. Silver plating may be used on contacting surfaces oftubing 45 for enhanced electrical conductivity if desired. As shown in the drawing, chuck 46 is formed of three outwardly bowedfingers 51 separated by milledgrooves 52, each finger having bowedouter surface 59. The tips offingers 51 have roundedexternal surfaces 53 and beveledsurfaces 54 sloping inward, as is clearly shown in FIG. A. The axial opening normally formed by thebeveled surfaces 54offingers 51 is slightly smaller in diameter thanrounded end 35 of electrode 32 so that the fingers are forced slightly apart upon insertion of the electrode, but because of their spring quality, firmly grip the electrode when thus spread. This gripping operation and mechanism will be further discussed below. At the op' posite end oftubing 45 isannular groove 47 which definesannular ridge 55. End coil 57 ofspring 56 is seated ingroove 47 so that contact between the spring andtubing 45 will be maintained whetherspring 56 is in tension or compression. it should be understood that, although acoil spring 56 is shown as a specific biasing means herein, the invention contemplates other biasing means which perform the same function.

Plunger 61 has ashank 62 slightly smaller thanaxial bore 48 intubing 45 and also smaller than axial opening 58 throughcoil spring 56. Plunger 61 is provided with aflat contact head 63 and anannular ridge 64 whichis separated fromhead 63 byannular groove 65. End coil 66 ofspring 56 is seated ingroove 65 to maintain contact between the spring and the plunger. Plunger 61 is thus slidably and resiliently coupled totubing 45 by means ofspring 56.Shank 62 extends through axial opening 58 inspring 56 and intobore 48 intubing 45, Coils 57 and 66 engagetubing 45 and plunger 61 respectively, thereby interconnecting the plunger and the tubing.Spring 56 is normally in compression, thereby biasingchuck 46 away fromcontact head 63. This operative relationship will be referred to again later.

Connector 67 is made of electrically conductive material and is provided withthreads 71 at one end separated fromcylindrical shank 72 at the other end byshoulder 73.Shank 72 is provided with longitudinal blind bore 74 having bevelededges 75 at its opening.Threads 71 are configured to mate withthreads 24 inadaptor 23.Flat end 76 ofconnector 67 is provided with a crosswise slot 77 shaped to receive a screwdriver blade for screwing the connector intoadaptor 23. Whenconnector 67 is properly mounted inadaptor 23,shoulder 73 abuts shoulder andshank 72 extends throughbore 26 intocounterbore 27.

Electrical cable termination 81 is a type well known in the art as a banana plug.Cable 31 is suitably connected to flexible electrically conductivemale contacting member 82 internally of electrically insulatingsleeve 83. The internal electrical connection is preferably the well known swivel type to thereby preventcable 31 from becoming twisted and entangled during use. The diameter ofsleeve 83 is slightly less than the diameter ofcounterbore 27 inadaptor 23. The banana plug is adapted to be removably connected to the instrument by insertion intoadaptor 23. The rounded end of contactingmember 82 is guided into connector bore 74 by means ofbeveled edge 75. The spring action of flexible contactingmember 82 provides a firm frictional engagement betweenbanana plug 81 andconnector 67.

The other end ofcable 31 terminates in a second swiveltype banana plug 84, as shown in HO. 1.Plug 84 may then be cou' pled to asuitable adaptor plug 85 which is in turn connected to a source of electrical power (not shown) by means of electricallyconductive shank 86.Plug 85 may have shanks of various shapes and sizes to fit different electrical outlets. Differences in power outlets will not affect use of this novel electrosurgical instrument and its power cable because of its universal type banana plug terminations. The only element which is subject to modification to fit different electrical outlets is theremovable adaptor plug 85.

In accordance with the novel principles of this invention, the fully assembled instrument, as shown in FIGS. 1 and 2 (disregarding for the moment the interchangeable electrode), is electrically continuous fromcable 31 through the conductive members within the handle and adaptor to chuck 46. The internal members comprise essentially ofconnector 67 havingflat end 76 which bears againstcontact head 63 of plunger 61, thereby partially compressingspring 56 and forcingchuck 46 intocounterbore 42 ofbushing 37. Asfingers 51enter bushing 37, bowedouter surfaces 59 bear more heavily against the surface ofcounterbore 42 and tend to urgefingers 51 together. When the chuck is fully inserted intobushing 37, rounded ends 53 offingers 51 bear against taperedshoulder 43 in the bushing forcing the fingers together in substantially closed condition. The assembled electrosurgical instrument is thus conditioned to receive surgical electrode 32 whenchuck 46 is biased as far as possible intobushing 37.

Bore 14 inhandle 11 is slightly larger thanelectrode shank 34 and is substantially the same diameter asbore 41 inbushing 37. Likewise, bore 15 is somewhat larger thaninsulative sleeve 36 and substantially larger thanshank 34. Withend 35 ofelectrode shank 34 being smoothly rounded, electrode 32 may be easily inserted into the electrode end ofhandle 11 without careful and time consuming aiming. The configuration of this end of the electrode allows it to slide offshoulder 17 into bore 14 and directly into the circle formed bybeveled surfaces 54 ofchuck fingers 51. Increasing the insertion force on the electrode causestubing 45 to yield longitudinally in handle bore 12, further compressingspring 56. ln response to this longitudinal motion, rounded ends 53 ofchuck fingers 51 retreat from taperedshoulder 43 ofbushing 37 androunded surfaces 59 bear less heavily on the side ofcounterbore 42, allowingchuck 46 to be opened slightly to admit the end ofelectrode shank 34. However, the biasing action ofspring 56 continuously urgeschuck 46 intobushing counterbore 42. Thus,

the biasing action ofspring 56 ensures thatelectrode shank 34 is firmly gripped at all times bychuck 46. The force with whichchuck 46 grips the electrode shank is such that the electrode is firmly held but may be readily removed by pulling with the fingers or with a suitable mechanical tool such as forceps. A certain satisfying positive gripping action is evident when the electrode is inserted or removed.

An important concept of this novel instrument resides ininsulative sleeve 36. This sleeve functions to provide a positive stop when electrode 32 is inserted intohandle 11. The sleeve fits tightly aroundshank 34 and abutstip 33, which thereby prevents its longitudinal movement past the electrode tip. When the electrode is in place, end 87 of the sleeve abutsshoulder 17 inhandle 11.Sleeve 36 may be made any practical length shorter thanshank 34 to provide any desired length of electrode extending from the electrode end ofhandle 11, provided that sufficient length ofshank 34 remains exposed to pass through bores 14 and 41 to be gripped bychuck 46. Since bore 15 is larger thansleeve 36, slight variations in the wall thickness of the sleeve are acceptable and will not adversely affect the instrument.

It should be noted that handle bore 15 provides a particularly significant and novel safety feature. It is possible that the electrode may, by accident, be not fully inserted or that it could be partially pulled out ofchuck 46 during handling and use. Bore 15 allows substantial longitudinal play of this type without resulting in any danger to the operator from electrical shock because the shank of electrode 32 is fully protected bysleeve 36 throughout its exposed length plus the length of bore 15. With the electrical power used in such instruments, this feature is significant from the standpoint of physical safety. It can be appreciated that during an operation, the surgeon's fingers might slip off or overlap fromhandle 11 onto the shank of electrode 32. Ifsleeve 36 was constructed to abut the very end of the handle, it is quite possible that a gap could exist between the sleeve and the insulative handle, exposing a portion ofelectrode shank 34 which could come in contact with the surgeon's hand. With the invention herein described, it is unlikely that electrode 32 will slide out sufficiently far to expose a portion ofshank 34 between the handle andsleeve 36,

but should such a condition occur, it will be detected by the increased protruding length of the electrode or by the fact that the electrode is not then held securely motionless in the handle or both. The size of bore 14 allows slight wobbling of the electrode to occur whensleeve 36 is not firmly butted againstshoulder 17.

With the electrode firmly in place, an electrical path is pro vided fromadaptor plug 85 throughcable 31 tobanana plug 81, thence throughconnector 67, plunger 61 andspring 56,shank 45 and chuck 46 to electrode 32. All electrically conducting contacting parts may be silvered if desired or if necessary for proper conductivity at the contacting surfaces.

Electrodes having tips with different shapes and sizes are readily accommodated by the novel instrument herein described. Similar electrodes may extend different distances from the handle depending upon thelength ofsleeve 36.

Having described one embodiment of this invention in detail, certain modifications and improvements will now occur to those skilled in this art. It is intended that the scope of the invention disclosed herein be limited only by the appended claims.

We claim:

1. An electrosurgical instrument, comprising:

an elongated electrically insulative handle having an electrical connection end, an electrode receiving end and a longitudinal bore therethrough;

a surgical electrode having a shank for insertion into said receiving end; an electrically conductive chuck longitudinally movable within said bore and formed with a plurality of flexible fingers in the region of said electrode receiving end, the ends of said fingers normally defining an axial opening smaller in cross section than said shank of said surgical electrode, said fingers being adapted to engage and releasably grip said shank of said surgical electrode;

means at said electrical connection end for receiving an electrical power cable for electrical connection to said conductive chuck;

means within said handle normally biasing said chuck toward said electrode receiving end;

said chuck being further adapted to yield longitudinally against said biasing means upon insertion of said shank into said axial opening defined by said fingers, said fingers being thereby spread to receive said shank; and

means coacting with said biasing means during the spread of said fingers for continuously urging said fingers into gripping engagement with said shank.

2. The electrosurgical instrument recited in claim 1, wherein the cross section of said surgical electrode shank and said axial opening are generally circular.

3. The electrosurgical instrument recited inclaim 2, and further comprising an electrically insulative sleeve closely surrounding a portion of the length of said electrode shank, said sleeve being substantially shorter than said shank.

4. The electrosurgical instrument recited inclaim 3, wherein:

said longitudinal bore through said handle is comprised of a first bore at said electrode receiving end, a smaller bore longitudinally adjacent thereto and a larger main bore extending throughout the remainder of said handle, said smaller bore defining a shoulder at the junction with said first bore;

said smaller bore being shaped and configured to receive said surgical electrode shank but smaller than the diameter of said sleeve;

said first bore being shaped and configured to receive said insulative sleeve; and

whereby one end of said sleeve abuts said shoulder and determines the extent to which said shank may be inserted into said electrode receiving end.

5. The electrosurgical instrument recited inclaim 4, wherein:

said surgical electrode has an exposed tip at one end and is smoothly convex at the other end;

said sleeve abuts said exposed tip; and

said convex end is adapted to be inserted through said electrode receiving end of said handle into said chuck.

6. The electrosurgical instrument recited in claim 5, wherein the ends of said fingers defining said axial opening are beveled inward, said beveled surfaces being adapted to receive and center said smoothly convex end of said electrode.

7. The electrosurgical instrument recited in claim 6, wherein said means for continuously urging said fingers into gripping engagement with said shank is a bushing mounted within said main bore at said electrode receiving end, said bushing abutting said smaller bore, said bushing having a bore of substantially the same size as said smaller bore and a counterbore adapted to receive the fingers of said chuck.

8. The electrosurgical instrument recited in claim 7, wherein:

said fingers are bowed outwardly and the transitional surfaces between the external bowed sides of said fingers and said inward beveled surfaces are smoothly convex;

the edge of said counterbore in said bushing is beveled inwardly and the transitional surface between said counterbore and said bore in said bushing is beveled inwardly; and

whereby said chuck fingers are guided into said bushing counterbore by said beveled edge, said bowed sides of said fingers bear against the side of said counterbore urging said fingers together under the action of said biasing means, and said smoothly convex surfaces of said fingers in biased contact with said beveled transitional surface in said bushing urges said fingers tightly closed, said axial opening being thereby substantially smaller than said electrode shank.

9. The electrosurgical instrument recited in claim 1, wherein said biasing means is an electrically conductive spring normally under compression between. said chuck and said electrical power cable receiving means, said spring providing electrical connection between said chuck and said electrical power cable receiving means.

10. The electrosurgical instrument recited in claim 7, wherein said first bore and said smaller bore together are substantially shorter than said electrode shank, whereby that portion of said shank which is free of said sleeve extends through said smaller bore and said bore in said bushing into said chuck.

11. A handle for use with and adapted to interchangeably and firmly receive a surgical electrode having a shank, said handle comprising:

an elongated electrically insulative body having an electrical connection end, an electrode receiving end and a longitudinal bore therethrough;

an electrically conductive chuck adapted to engage and releasably grip the shank of said surgical electrode, said chuck being longitudinally movable within said bore and formed with a plurality of flexible fingers in the region of said electrode receiving end, the ends of said fingers normally defining an axial opening smaller in cross section than the electrode shank which said chuck is adapted to receive;

means at said electrical connection end for receiving an electrical power cable for electrical connection to said conductive chuck;

means within said body normally biasing said chuck toward said electrode receiving end;

means coacting with said biasing means for continuously urging said fingers together; and

said chuck being adapted to yield longitudinally against said biasing means to enable said fingers to spread apart sufficiently to forcibly receive said electrode shank.

12. The handle recited inclaim 11, wherein said biasing means is an electrically conductive spring which is normally in compression and provides electrical contact between said chuck and said electrical power cable receiving means.

13. The handle recited inclaim 12, wherein:

said means for continuously urging said fingers together is a bushing fixed within the electrode receiving end of said receiving end, a smaller bore longitudinally adjacent thereto and a larger main bore extending throughout the remaining length of said body, the transitional surface between said first bore and said smaller bore being normal to the axis of said bores and defining a shoulder facing said electrode receiving ends 15 The handle recited in claim l4, wherein the bore in said bushing is substantially the same size as said smaller borer

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