US3807404A

US3807404A - Probe unit for electro-surgical device

Info

Publication number: US3807404A
Application number: US00340294A
Authority: US
Inventors: B Weissman; A Miller; W Fredericks
Original assignee: Whaledent Inc
Current assignee: Coltene Holding AG
Priority date: 1973-03-12
Filing date: 1973-03-12
Publication date: 1974-04-30
Anticipated expiration: 1991-04-30
Also published as: DE2404764A1; CH570808A5; GB1430694A; JPS49126193A; CA1015404A; IT1015865B; FR2221112B1; DK142761C; JPS5446189U; JPS5554487Y2; SE396696B; FR2221112A1; DK142761B

Abstract

A probe unit for applying high level high frequency voltages to tissues to be treated has a tubular handpiece having an operative end and a female connector fixed at the operative end and connectable to a source of high level high frequency voltage. An interchangeable plastic nose piece, which can be conical or contra-angled in shape, includes a proximal end provided with a mating male connector electrically engageable with the female connector. An elongate conductor sleeve is in electrical communication with the male connector and extends to a distal end remote from the proximal end of the nose piece. A disposable probe tip, which includes a cutting tip, is configurated so as to be receivable in the elongate sleeve of the nose piece. The probe tip has an elongate insulating cylindrical shell having two axial slots. A resilient conductive wire, which forms part of the external cutting tip, extends partially interiorly of the shell to form two spaced opposing resilient arcuate portions which pass through the respective slots and which are depressible into the shell. In this manner, insertion of the shell into the sleeve depresses the arcuate portions to thereby provide frictional engagement and electrical contact between the cutting tip and the sleeve.

Description

United States Patent [1 1 Weissman et al.

[451 Apr. 30, 1974 PROBE UNIT FOR ELECTRO-SURGICAL DEVICE [75] Inventors: Bernard Weissman, New York; Alan Neil Miller, New City; Walter Henry Fredericks, White Plains, all of NY.

[73] Assignee: Whaledent, Inc., New York, N.Y.

[22] Filed: Mar. 12, 1973 [2]] Appl. No.: 340,294

Primary ExaminerChanning L. Pace Attorney, Agent, or F irm-Friedman & Goodman I [5 7] ABSTRACT A probe unit for applying high level high frequency voltages to tissues to be treated has a tubular handpiece having an operative end and a female connector fixed at the operative end and connectable to a source of high level high frequency voltage. An interchangeable plastic nose piece, which can be conical or contra-angled in shape, includes a proximal end provided with a mating male connector electrically engageable with the female connector. An elongate conductor sleeve is in electrical communication with the male connector and extends to a distal end remote from the proximal end of the nosev piece. A disposable probe tip, which includes a cutting tip, is configurated so as to be receivable in the elongate sleeve of the nose piece. The probe tip has an elongate insulating cylindrical shell having two axial slots. A resilient conductive wire, which forms part of the external cutting tip, extends partially interiorly of the shell to form two spaced opposing resilient arcuate portions which pass through the respective slots and which are depressible into the shell. In this manner, insertion of the shell into the sleeve depresses the arcuate portions to thereby provide frictional. engagement and electrical contact between the cutting tip and the sleeve.

15 Claims, 6 Drawing Figures 1 PROBE UNIT FOR ELECTRO-SURGICAL DEVICE .BACKGROUND OF THE INVENTION tal operations are well known in the art. Such devices generally comprise a source of high level high frequency voltage whose application to a cutting tip can be manually controlled. Such devices can be used for general, medical and dental purposes.

However, the probe units utilized in conjunction with electro-surgical devices of the prior art have several drawbacks which the present invention resolves. For example, the conventional probe unit is provided with a handpiece on which is mounted, at the operative end, a chuck. The chuck utilized is not unlike that used on drills. The probe or operating tip is inserted into the chuck and the latter is adjusted to provide a secure grip on the operating tip simultaneously providing electrical continuity between the high level highfrequency voltage source and the operating tip of the probe unit. Theconventional arrangement is inconvenient since, in order to "provide good electrical contact, the chuck must be tightened this frequently requiring an additional tool. Also, the chuck forms a permanent part of the probe unit, this limiting the available configurations provided at the operative end for use in special medical procedures. The operating tip of the prior art 'is not disposable and is reused after appropriate treatment of the tip. Consequently, the probe unit of the prior art frequently causes time delays resulting from the necessity of first sanitizing the operating tip subsequent to a prior operation. An additional disadvantage of the prior art probe units is that the probe tip, once secured in the chuck, is not capable of rotation within the chuck. Consequently, in order to orient the. operating tip in a desired position, it is necessary to rotate or manipulate the handpiece. In order to change the orientation of the operating tip during an operation, the chuck first has to be loosened so as to loosen the operating tip. A still further disadvantage of the conventional probe unit is the inconvenient placement of the power control switch. The conventional elec-tro-surgicaldevice typically includes a console which is connected to the probe unit by means of a coaxial cable. The power control switch has commonly been provided on the console; Such an arrangement requires the user to turn 'to the console whenever the power is to be turned on or off an inconvenience which is time consuming.

SUMMARY OF THE INVENTION It is accordingly a primaryobject of thepresent invention to provide a probe unit for an :electro-surgical device which is not possessed of the above described disadvantages associated with conventional probe units.

it is another object of the present invention to'provide a probe unit as described above which is simple in construction and economical to manufacture.

It is still another object of thepresent invention to provide a probe unit of the type under discussion which provides a power control switch on the handpiece to facilitate control of power flow to the probe or operating tip.

Itis yet a further objectof the present invention to provide a probe unit which utilizes interchangeable plastic nose pieces which include electrical connectors mateable with a corresponding connector on the handpiece or hand held portion and which also includes a conductive sleeve into which disposable probe tips can be inserted.

It is a further object of the present invention to provide a probe unit which can be utilized with plastic nose pieces having different configurations and which can be frictionally engaged with the hand held portion.

It is still a further object of the present invention to provide a probe unit which is rotatable subsequent to being assembled or connected to the hand held portion.

It is yet a further object of the present invention to provide a probe unit having .a disposable probe tip which is frictionally engageable with a respective nose piece of the unit.

It is an additional object of the present invention to provide a disposable probe tip which is simple in construction and economical to manufacture.

In order to achieve the above objects, as well as others which will become apparent hereafter, a probe unit for applying a high level high frequency voltage to tissue to be treated, in accordancewith the present invention, comprises an elongate tubular handpiece having an operative end. A conductive connector element is disposed at said operative end and is connectable to a source of high level high frequency voltage. An elongate nose piece has a proximal end and a distal end. Said proximal end is providedwith a portion generally having configuration complimentary to said operative end and said connector element. Electrical conductor means extends between said proximal and distal ends. Said conductor means includes a portion at said proximal end engageable with said connector element and a conductive sleeve portion at said distal end. A probe tip comprises an elongate insulating cylindrical shell receivable in said sleeve portion. Said shell has two opposing axial .slots and a narrowed axial end. A resilient wire forms a first'po'rtion extending beyond said narrowed axial end to form an external operating tip. The resilient wire also formsa second portion disposed inside said shell. The second portion is provided with two spaced opposing resilient arcuate portions passing through said respective slots and being depressible into said shell. In thismanner, insertion of said shell'into said sleeve portion partially depresses saidarcuate portion to thereby provide frictional engagement and electrical contact between said wire and said sleeve portion. a

In accordance with a presently preferred embodi ment, said handpiece is connected to a source of high level high frequencyvoltage. A switch is mounted on said handpiece at said operative end. The switch is operatively connected to the source of voltage so that the application of voltage of the probe tip is controllable by manipulating said switch on said handpiece. Said conductive connector element comprises a female connector and the conductor means portion at said proximal end comprises a male connector engageable with said female connector. K

- The nose piece is advantageously made from plastic and has a proximal end which is exteriorly cylindrical.

The distal end of the nose piece can either be conical or contraangled in shape the distal ends being tapered away from said proximal end in each case. The sleeve portion is embedded in and extends through the distal end of the plastic nose piece. Advantageously, biasing means is interposed between the operative end and the nose piece to provide frictional retention therebetween.

The present invention also contemplates a novel disposable probe tip which is insertable into a conductive sleeve of a probe unit utilized in conjunction with an electro-surgical device. The resilient wire is, according to the preferred embodiment, a continuous section substantially doubled up with the two wire ends forming part of said second wire portion disposed inside said shell. Said first portion is generally in the form of a diamond shaped loop. The wire is configurated in a manner so that the loop defines a first plane and the second wire portion defines a second plane substantially normal to the first plane.

BRIEF DESCRIPTION OF THE DRAWINGS With the above and additional objects and advantages in view, as will hereinafter appear, this invention comprises the devices, combinations and arrangements of parts hereinafter described and illustrated in the accompanying drawings of a preferred embodiment in which:

FIG. 1 is a longitudinal cross sectional view of the probe unit in accordance with the present invention;

FIG. 2 is an exploded enlarged view of the operative end of the probe unit of FIG. 1, showing a nose piece and a probe tip separated from the handpiece but aligned for engagement and mutual connection;

FIG. 3 is similar to FIG. 2, but showing a differently shaped nose piece connected to the handpiece, and the probe tip mounted in the nose piece;

FIG. 4 is an enlarged top view of a probe tip in accordance with the present invention;

FIG. 5 is a longitudinal cross section taken through line 5-5 of FIG. 4; and

FIG. 6 is a transverse cross section taken through line 6-6 of FIG. 4.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, in which identical or similar parts have been designated by the same reference numerals throughout, and first referring to FIG. 1, a probe unit in accordance with the present invention is generally designated by the reference numeral 10. The probe unit 10 comprises a plastic tubular housing 12 which has an operative end 13. Removed from the operative end is a transparent tubular wall or lens 14 which is connected to the tubular housing 12 and forms therewith a hand held portion or handpiece of the probe unit.

Provided at the operative end 13 of the tubular housing 12 is a connector element in the form of a female connector 20. A pin 22 secures the connector 20 to the operative end of the tubular housing 12.

A synthetic resin nose piece 24, to be more fully described hereafter, includes a proximal cylindrical section 26 which is internally dimensioned in a complimentary manner to the shapes of operative end 13 and connector element 20 so as to receive the same interiorly thereof. A spring 28 is advantageously provided between the operative end 13 and the cylindrical section 26 to increase the extent with which frictional engagement is obtained for insuring frictional retention between the nose piece 24 and the operative end 13.

Electrical conductor means including a male connector pin 30 is provided at a proximal end of the nose piece 24 which is adapted to be electrically engageable with the female connector 20.

A conductive sleeve 32, in electrical communication with the connector 30, forms part of the electrical conductor means and extends through a distal end of the nose piece 24 opening exteriorly of the nose piece so as to have the interior of the conductive sleeve 32 exteriorly accessible.

A probe tip 33 in accordancewith the present invention comprises a substantially cylindrical shell 34 whose external dimensions closely approximate the internal dimensions of the conductive sleeve 32 so that the shell is receivable in the latter. Provided in the cylindrical wall of the shell 34 are two oppositely disposed axial slots 35, to be more fully described hereafter. A conductive resilient wire 37 is provided interiorly of the shell 34, arcuate portions 36 thereof extending through the axial slots 35. Another portion of the resilient portion extends through an open axial end of the shell 34 to form a substantially closed loop 38 in the form of a cutting tip.

The details of the operative end 13 of the probe unit 10, including the connector element 20, the nose piece 24 and the probe tip 33 will be described more fully in connection with FIGS. 2-6.

Disposed at an opposite axial end to the operative end 13 is an opening in the lens 14 through which a coaxial cable 40 enters interiorly'of the probe unit 10. In order to relieve some of the tension on the coaxial cable 40, a shrink tube 42 is advantageously provided which encloses and supports the coaxial cable. The coaxial cable is advantageously provided with conductors which carry the high level high frequency voltages to the probe unit 10. The electrical arrangement for accomplishing this is well known to those skilled in the art. Typically, the high level high frequency voltage carrying conductor 40a of the coaxial cable 40 is directly connected to the connector element 20. A portion 40b of the high level high voltage carrying cable is also connected to one lead of a neon lamp 44 the other lead (not shown) of the neon lamp being capacitively coupled to the grounded shield 40c on the coaxial cable 40. Such capacitive coupling limits the maximum current passing through the neon lamp 44. Also, the lamp glows and thereby provides an indication of when the voltage at the cutting tip 38 exceeds the breakdown voltage of the lamp 44 and high level high frequency voltage is being applied to the cutting tip 38.

The specific arrangement of the high level high frequency voltage cables and their connections i'nteriorly of the probe unit 10 are conventional and any other arrangement for applying the desired voltages to the cutting tip 38 may be utilized.

The probe unit 10 is connected to an electro-surgical device which generates the high level high frequency voltage. The probe unit is connected to the console by means of the coaxial cable 40. One of the novel features of the present invention is the provision of a micro-switch 46 at the operative end 13 of the tubular housing 12. This facilitates the control of power flow to the cutting tip 38 in a very convenient manner. By placing the micro-switch 46 at the operative end 13, the switch is positioned approximately in the region of the users thumb when the probe is held in a normal or ordinary manner. Consequently, the user can conveniently and quickly turn the power on and off by merely depressing or releasing the microswitch 46.

A supporting

block comprisingportions

48a and 48b is provided interiorly of-the probe unit 10, the supporting block being provided with a suitableopening or slot for the insertion of the micro-switch 46. However, any other suitable means for supporting the micro-switch 46 may be utilized.

Referring to FIG. 2, the operative end of the probe unit is shown in an exploded view with the various components aligned for mutual connection.

The operative end of the tubular housing 12 is provided with a cylindrical shell 49 which has a somewhat reduced external diameter from the diameter of the tubular housing 12. 1

Positioned interiorly of the cylindrical shell 49 is the connector element 20 which is conductive and preferably made from a metal such as copper. Extending beyond the main portion of the connector element 20 is a cylindrical projection 50. An axial bore 52 extends substantially through the entire connector 20, the diameter of the axial bore 52 being substantially equal to the outer diameter of the connector pin 30 so that engagement therebetween provides a good electrical connection.

It is possible, of course, to provide an axial bore, corresponding to bore 52, in the nose piece 24 while having a pin corresponding to pin 30 connected to the conductor 20. In this case, the positions of the male and female members are merely interchanged.

The nose piece 24 has .a proximal end which has a substantially cylindrical exterior 60 which is hollow to provide a cylindrical recess or cavity 61. The internal diameter of the recess 61 is substantially equal to the outer diameter of the cylindrical shell 49 so as to provide a press fit when the two are mated with one another. However, according to another mode of operation, it is possible to provide some clearance betweenthe cylindrical shell 49 and the cylindrical recessed portion 61, as illustrated in FIG. 2. With such an arof other cross section which nevertheless incorporates the principles of the present invention. Thus, for example, the cylindrical shell 49 as well as the cylindrical recessed portion 61 can readily be made to have square or rectangular cross sections instead of being circular.

Still referring to FIG. 2, a probe tip 33 is shown which includes a generally cylindrical hollow shell 34. The sleeve 32 is selected to have a length sufficient to accommodate most of the axial length of the shell 34, as illustrated in FIG. 1.

The shell 34 has a flared resilient end 64 whose external dimensions are somewhat greater than the internal dimensions of the sleeve 32. However, because of the resilient nature of the end 64, the latter can be forced interiorly of the sleeve 32 while resiliently abutting thereagainst so as to enhance the fricational engagement therebetween and prevent the undesired outward movement of the probe tip 33 under normal conditions of ,use. At the axial end remote from the flared resilient end 64 is a narrowed end 66, as best shown FIG. 5, to be described hereafter.

In FIG. 3, a modified nose piece 24 is provided which has a different configuration from the conical nose piece illustrated in FIG. 2. However, in all other respects, the nose piece 24' is similar to the nose piece 24. In FIG. 3, the nose piece 24 as well as the probe tip 33' have been connected to each other as during normal use. Thus, the cylindrical shell 49 is enclosed by rangement, at least one spring 28 is advantageously provided at the outer peripheral surface of the cylindrical shell 49 which is compressed into a biasing condition when the nose piece is mounted on the tubular housing 12. The purpose of this spring 28 is to enhance axial bore 52, the pin 30 and the sleeve 32 are generally coaxial and aligned along the axis of symmetry of the tubular housing 12.

Although the above described elements have been shown to be cylindrical, it should be clear that one skilled in the art can readily change the general shape of the components to provide an operative probe unit the cylindrical proximal end 60 with the compressed spring 28 disposed therebetween. The male connector pin 30 is engaged with the axial bore 52 at the connector 20 to provide good electrical contact between the two connectors.

The distal end of the modified nose piece 24' is commonly designated'as having a contra-angled form wherein a substantially straight proximal section 72 is angularly disposed with respect to a substantially straight distal section 74. A sleeve section 76 is disposed at the proximal section while a sleeve section 78 is disposed in the distal section 74, the

sleeve sections

76, 78 being in electrical connection with one another. Since the sleeve section 76 is in electrical contact with the pin 30 of the male connector, electrical continuity is provided between the connector 20 and the sleeve section 78 via the connector 30 and the sleeve section 76. With this modified arrangement, the probe tip 33 is receivable in the sleeve section 78 in a similar manner as the probe tip is receivable in the conductive sleeve 32 of FIG. 1. The cutting tip 38 is in electrical contact with the respective sleeves by virtue of a pressfit contact between the arcuate portions 36 and the sleeves, as will become apparent from a description of FIGS. 4-6.

The novel probe tip 33 in accordance with the present invention which is suitable for use with the probe unit, described above, generally comprises a shell 34 which. is essentially cylindrical. However, one end thereof, namely end 64, is flared and is resilient in nature by virtue of the provision of axial slots 80. Consequently, the flared resilient end 64 can be compressed when made from any suitable plastic material.

Approximately midway between the two ends 64, 66 of the shell 34, there are provided two oppositely disposed axial slots 35 inthe wall of the shell. The end 66, remote from the flared end 63, is pinched or has a narrowed section, for reasons to be described.

A single section of wire 37 is provided which has two ends 82 disposed interiorly of the shell 34. The wire 37 is essentially doubled up whereby the two ends 82 are disposed interiorly of the shell 34 while a portion of the wire extends through the narrowed end 66 to form a substantially closed diamond-shaped loop 38, in the form of a cutting tip. The portions of the wire 37 which are disposed interiorly of the shell 34 are provided with two spaced arcuate sections 36 each of which is directed in opposite directions and which extend through respective slots 35.

The two arcuate portions 36 together define a plane. The wire portions which form transitions between the arcuate portions 36 and the cutting tip loop 38 diverge gradually from the plane of the arcuate sections 36 into a further plane defined by the loop 38, the plane and the loop being substantially normal to the plane of the arcuate portions 36. The transition is substantially completed on the arcuate portion 36 side of the narrowed end 66, as best seen in FIG. 6.

As will be appreciated, the twisted configuration of the wire 37, taken together with the narrowed end 66, prevents the wire from leaving the shell 34 even when the arcuate sections 36 are compressed therein. This result arises because the gradually divergent transition portions of the wire 37, even when the arcuate portions 36 are compressed, define distances greater than the height of the narrowed portion 66.

When the probe tip 33 is inserted into the sleeve 32 or sleeve section 78, the arcuate portions 36 as well as the flared resilient end 64 are inwardly or radially compressed so as to conform to the internal diameters of the sleeve. Since the shell material 34, as well as the wire 37 are made of resilient materials, both the flared end 64 as well as the arcuate portions 36 resiliently apply outward forces against the internal surface of the sleeve. With respect to both the flared resilient end 64 as well as with respect to the arcuate portion 36, the resilient biasing forces exerted thereby increase the frictional engagement between the probe tip 33 and the

nose piece

24 or 24. However, with respect to the arcuate portions 36, this also provides electrical contact between the wire 37 and the conductive sleeves.- In this manner, the high level high frequency voltages applied to the connector are transmitted to the cutting tip 38.

It should now be evident, the above described constructions overcome the disadvantages described in the prior art. Thus, the provision of a micro-switch 46 at the operating end 13 facilitates the control of power to the cutting tip 38. By providing

nose pieces

24, 24, as described above, the nose pieces can readily be removed by disengaging the latter from the tubular housing 12. This permits interchangeability of differently shaped nose pieces and selection of a nose piece which is most suitable for a particular application.

Another advantage of the subject invention is the provision in the nose piece of a conductive sleeve which is conflgurated to receive a dispensable probe tip 33. As should beevident from the above description, as well as from FIGS. 46, the probe tips 33 are simple and economical to manufacture. Consequently, they can be made at low enough costs so as to makethe same dispensable. This obviates the need for treating tips subsequent to previous surgical procedures when they are needed. Of course, this also eliminates the possibility that an improperly treated cutting tip may cause infection in the treated patient. It is contemplated, for example, that each probe tip 33 be individually and sanitarily packaged whereby each probe tip is only utilized for one surgical operation.

It will also be appreciated that the subject invention permits the relative rotation of the

nose piece

24 or 24 with respect to the tubular housing 12. When a contraangled nose piece 24' is utilized, this facilitates orientation of a probe tip in a simple and efficient manner, even during an operative procedure. Since the pin 30 remains engaged with the connector 20 during such relative rotary motion, electrical continuity is assured even if relative rotation of the nose piece is effected while the voltages are applied.

Similarly, the probe tip 33 can be rotated relative to the nose piece in which it is positioned. In this connection, it will be noted that there are not provided any latching means which prevent this rotation. Thus, it is possible to orient, for example, the plane defined by the cutting tip or loop 38 in any desired plane by simply gripping the cutting tip or shell 34 and turning it relative to the nose piece. When this is done, a force only sufficient to overcome the frictional engagement between the sleeve and the resilient end 64 and between the sleeve and the arcuate portions 36 must be overcome.

The probe unit 10 in accordance with the present invention thereby economically facilitates convenient interchangeability as well as adjustment or orientation of the operative elements of the probe unit. Such versatility has not been provided in conventional probe units.

Numerous alterations of the structure herein disclosed will suggest themselves to those skilled in the art. However, it is to be understood that the present disclosure relates to a preferred embodiment of the invention which is for purposes ofillustration only and is not to be construed as a limitation of the invention.

What is claimed is:

1. In an electro-surgical device, a probe unit for applying high level high frequency voltages to tissue to be treated, said probe unit comprising an elongate tubular handpiece having an operative end; a conductive connector element disposed at said operative end adapted to be connected to a source of high level high frequency voltage; an elongate nose piece having a proximal end and a distal end, said proximal end being provided with a portion generally having configuration complementary to said operative end and said connector element; electrical conductor means extending between said proximal and distal ends, said conductor means including a portion at said proximal end engageable with said connector element and a conductive sleeve portion at said distal end; and a probe tip comprising an elongate insulating cylindrical shell receivable in said sleeve portion, said shell having two opposing axial slots and a narrowed axial end, and a resilient wire forming a first portion extending beyond said narrowed axial end to form an external operating tip and forming a second portion disposed inside said shell, said second portion being provided with two spaced opposing resilient arcuate portions passing through said respective slots and being depressible into said shell, whereby insertion of said shell into said sleeve portion partially depresses said arcuate portions to thereby provide frictional engagement and electrical contact between said wire and said sleeve portion.

2. A probe unit as defined in claim 1, wherein said handpiece is connected to a source of high level high frequency voltage, further comprising a switch mounted on said handpiece at said operative end, said switch being operatively connected to the source of voltage, whereby the application of voltage at said probe tip is controllable by manipulating said switch.

' 3. A probe unit as defined in claim 1, wherein said conductive connector element comprises a female'connector, and said conductor means portion at said proximal end comprises a male connector engageable with said female connector.

4. A probe unit as defined in claim 1, wherein said operative end and said connector element together define a cylindrical end portion, said proximal end of said nose piece being provided with a cylindrical recessed portion adapted to view said cylindrical end portion.

5. A probe unit as defined in claim 4, further comprising biassing means interposed between said cylin-.

drical and recessed portins for providing frictional re-. tention therebetween.

6. A probe unit as defined in claim 1, wherein said nose piece proximal end is cylindrical exteriorly, said distal end being conical exteriorly tapered away from said proximal end.

7. A probe unit as defined in claim 1, wherein said nose piece is formed of synthetic resin, and said sleeve portion is embedded in and extends through said distal end of said plastic nose piece.

8. A probe unit as defined in clain 1, wherein said nose piece proximal end is cylindrical exteriorly, said distal end being contra-angle shaped and tapered away from said proximal end.

9. A probe unit as defined in claim 1, wherein said wire is a continuous section substantially doubled up with the two wire ends forming part of said second portion disposed inside said shell, and said first portion is in the form of a loop.

10. A probe unit as defined in claim 9, wherein said loop is diamond shaped.

11. A probe unit as defined in claim 9, wherein said loop defines a first plane, and wherein said second wire portion defines a second plane substantially normal to said first plane.

12. A probe tip insertable into a conductive sleeve of a probe unit utilized in conjunction with an electrosurgical device, said tip comprising an elongate insulating cylindrical shell receivable in said sleeve portion, said shell having two opposing axial slots and a narrowed axial end, and a resilient wire forming a first portion extending beyondsaid narrowed axial end to form an external operating tip and forming a second portion disposed inside said shell, said second portion being provided with two spaced opposing resilient arcuate portions passing through said respective slots and being depressible into said shell, whereby insertion of said shell into said sleeve portion depresses said arcuate portions to thereby provide frictional engagement and electrical contact between said wire and said sleeve portion.

13. A probe unit as defined in claim 9, wherein said wire is a continuous section substantially doubled up with the two wire ends forming part of said second portion disposed inside said shell, and said first portion is in the form of a loop.

14. A probe unit as defined in claim 13, wherein said loop is diamond shaped.

15. A probe unit as defined in claim 13, wherein said loop defines a first plane, and wherein said second wire portion defines a second plane substantially normal to said first plane.

Claims

3. A probe unit as defined in claim 1, wherein said conductive connector element comprises a female connector, and said conductor means portion at said proximal end comprises a male connector engageable with said female connector.

5. A probe unit as defined in claim 4, further comprising biassing means interposed between said cylindrical and recessed portins for providing frictional retention therebetween.

10. A probe unit as defined in claim 9, wherein said loop is diamond shaped.

12. A probe tip insertable into a conductive sleeve of a probe unit utilized in conjunction with an electro-surgical device, said tip comprising an elongate insulating cylindrical shell receivable in said sleeve portion, said shell having two opposing axial slots and a narrowed axial end, and a resilient wire forming a first portion extending beyond said narrowed axial end to form an external operating tip and forming a second portion disposed inside said shell, said second portion being provided with two spaced opposing resilient arcuate portions passing through said respective slots and being depressible into said shell, whereby insertion of said shell into said sleeve Portion depresses said arcuate portions to thereby provide frictional engagement and electrical contact between said wire and said sleeve portion.

14. A probe unit as defined in claim 13, wherein said loop is diamond shaped.