US3478744A - Surgical apparatus - Google Patents

Description

United States Patent 3,478,744 SURGICAL APPARATUS Harry Leiter, 107 Henley Road, Philadelphia, Pa. 19151 Filed Dec. 30, 1964, Ser. No. 422,115 Int. Cl. A61b 17/38; A6111 3/02 US. Cl. 128-30314 17 Claims ABSTRACT OF THE DISCLOSURE and scarring of tissues during the cutting, coagulating and bonding of living tissue is minimized and better healing and stronger seams are provided.

The invention relates to surgical apparatus, and more particularly to apparatus providing a high frequency signal for use in electrosurgery.

Although electrosurgical apparatus has been heretofore provided, such apparatus have had the disadvantage in causing living tissue which is being surgically cut or coagulated to be burned or charred. Scar tissue has also resulted from use of such prior art equipment which has interferred with the healing and bonding of incision, made with such equipment.

It is therefore the principal object of the invention to provide a new and improved surgical apparatus for use in electrosurgery which minimizes burning, charring and scarring of tissues during the cutting, coagulating or bonding of living tissue.

Another object of the invention is to provide a new and improved surgical apparatus for use in electrosurgery which allows use of surgical instruments in the manner previously used with prior art apparatus, but minimizes burning, charring and production of scar tissue.

Another object of the invention is to provide a new and improved surgical apparatus for electrosurgery which allows incisions in living tissue and coagulation providing better healing and stronger seams in tissue operated upon.

Another object of the invention is to provide a new and improved surgical apparatus for electrosurgery which is particularly well adapted for use in organ transplants by producing less charring when tissue is cut and better coagulating and bonding where tissues are seamed with improved healing.

Another object of the invention is to provide a new and improved surgical apparatus for electrosurgery which is simple in structure, produces optimum results, and is highly reliable in operation.

The above objects as well as many other objects of the invention are achieved by providing a surgical apparatus comprising first means for generating a high frequency signal for use in electrosurgery, second means providing a plurality of signal bursts of said high frequency signal, and third means delivering said bursts of said high frequency signal during the first period of the timing cycle and preventing the delivery of said high frequency signal during the second period of said cycle.

The first means may produce a high frequency signal between 1 megacycle per second and 8 megacycles per second, while said second means provides bursts of said high frequency signal between 1,000 bursts per second and 200,000 bursts per second, and said third means has a timing cycle equal to or less than 2 seconds.

The foregoing and other objects of the invention will become more apparent as the following detailed description of the invention is read in conjunction with the drawings, in which:

FIGURE 1 schematically illustrates a surgical apparatus partially in block form embodying the invention,

FIGURE 2 graphically illustrates the signal produced bythe cycle timer,

FIGURE 3 graphically illustrates the signal produced by the multivibrator circuit,

FIGURE 4 graphically illustrates the envelopes of the plurality of bursts of high frequency signals produced by the, apparatus, and

FIGURE 5 illustrates in block form a modified embodiment of the appartus shown in FIGURE 1.

Like reference numerals designate like parts throughout the several views.

,Refer to FIGURE 1 which schematically illustrates asurgical apparatus 10 for use in electrosurgery embodying the :invention.

Theapparatus 10 is provided withpower supply terminals 12, 14 for receiving a 60 cycle alternating signal. Terminal 12 is connected by aline 16 to theprimary winding 18 of apower transformer 20, which winding 18 is returned through afoot switch 22 and by the line 24 toterminal 14. Thefoot switch 22, upon actuation allows delivery of alternating signal to the input winding 18 of thetransformer 20 and is bridged by aseries capacitor 26 andresistor 28.

Thesecondary winding 30 has acenter tap 32 which is returned to ground potential andends 34 and 36 which are respectively connected to the end anode of a plurality of,series connectedrectifier diodes 38 and 40. The end cathodes of the series connecteddiodes 38 and 40 are connected together and returned through acapacitor 42 to ground potential, as well as being connected through asmoothing choke 44 to the anode 46 of the oscillator triode valve 48 of anoscillator circuit 49. The anode 46 of valve 48 is also connected to thecontrol electrode 50 of valve 48 through a blocking capacitor 52 which is connected in series with the parallel combination ofcapacitor 54 and inductor 56 of the tank circuit ofoscillator circuit 49, and blocking capacitor 58. Thecontrol electrode 50 of valve 48 is also connected through aRF. choke 60 in series with aresistor 62 to thecathode 64 of agate valve 66.

The filament 68 of valve 48 is connected to lines 70, 72 which are joined to the step-down winding 74 of afilament transformer 76 having itsprimary winding 78 connected withlines 16 and 24 for energization. Thesecondary winding 74 has acenter tap 80 which is returned to ground potential, while lines 70 and 72 are also connected through R.F. by-pass capacitors 82, 84 to ground potential.

=Theheater 86 ofgate valve 66 is also connected to lines 70,72 for energization, while theanode 88 is returned directly to ground potential and thescreen electrode 90 is connected through aresistor 92 to ground potential.

Thefirst control electrode 94 ofgate valve 66 is connected to a mutlivibrator circuit 96 which may produce a signal between 1 kilocycle per second and 200 kilocycles per second and is illustrated inapparatus 10 as having a frequency of 5 kilocycles per second. Thesecond control electrode 98 ofgate valve 66 is connected to acycle timer 100. Thecycle timer 100 may be of the type Which may be set to provide a cycle of two Seconds or less including a first period during which a positive output signal is delivered and a second period during which a negative output signal is delivered. The cycle timer illustrated delivers a cycle of one second with a positive signal for one/half second and a negative signal for the remaining one/half second of each cycle. Cycle timers of this type are well known in the art and may be in the form of mechanical stepping switches or electrical delay circuits.

The inductor 56 of the oscillator tank circuit ofoscillator circuit 49 provides afirst tap 102 to which is connected to thecoagulating terminal 104 through avariable capacitor 106 and afixed capacitor 108. The desiccating terminal 110 of the apparatus is connected to thecoagulating terminal 104 through achoke coil 112. The surgical terminal 114 is connected to asecond tap 116 of the inductor 56 through a variable capacitor 118 and afixed capacitor 120. The conduction orground terminal 122 is connected through acapacitor 124 to a third tap 126 of the inductor 56 which tap 126 is directly returned to ground potential. The inductor 56 is also provided with a shield 128 which is also returned to ground potential.

In operation of theapparatus 10, the appropriate surgical instrument is connected to the coagulating, desiccating orsurgical terminal 104, 110 or 114, as required, and the conductive ground or sheet upon which the patient may be positioned is connected to theconductive terminal 122. In order to apply the necessary power or high frequency signal required in coagulating, desiccating or surgery to the appropriate instrument attached to one of theterminals 104, 110 or 114, the operator closes thefoot switch 22 applying power to theprimary winding 18 oftransformer 20. With the application of power the high voltage signal produced in thesecondary winding 30 of the transformer is rectified by means of theseries crystal diodes 38, 40, and thesmoothing choke 44. With high voltage delivered to the anode 46 of oscillator valve 48 theoscillator circuit 49 produces oscillation in the tank circuit including thecapacitor 54 and inductor 56. However, oscillations will not be produced unless thecontrol grid 50 of valve 48 is returned to ground potential through thechoke 60 andresistor 62 by the conduction of thegate valve 66. When thevalve 66 is nonconducting, thegrid 50 is biased to cut-off and the valve 48 becomes non-conducting and does not allow the oscillations in the tank circuit to be sustained, terminating oscillation of thecircuit 49. During the production of oscillations, at high frequency signal which may be in a range from 1 megacycle per second to 8 megacycles per second for use in electrosurgery, is delivered to theterminals 104, 110, 114 of the apparatus by connection with the taps on the inductor 56. Thevariable capacitors 106 and 118 may have their capacities varied to adjust the amplitude of the high frequency signal delivered to theterminals 104, 110, and 114.

FIGURE 2 schematically illustrates the signal 130 delivered by thecycle timer 100. The signal 130 haspositive portions 132 extending for a period of .5 second with alternate negative portions 134 also extending for a period of .5 second. The cycle of the signal 130 is illustrated as having a period of 1 second and containing first positive and secondnegative portions 132, 134 in each cycle. During delivery of thepositive portion 132 of the signal 130 to thecontrol electrode 98 of thevalve 66, the valve is not inhibited from conducting. However, during the succeding portion 134 of the signal 130, the negative signal delivered to thecontrol electrode 98 of thevalve 66 prevents it from conducting. This prevents oscillation of theoscillator circuit 49 and results in no delivery of an output signal to theterminals 104, 110, 114 of theapparatus 10 during this time interval.

FIGURE 3 schematically illustrates thesquare wave signal 136 continuously produced by the multivibrator 96. During delivery of thepositive portion 138 of thesquare wave signal 136, thevalve 66 is not inhibited by this signal from conducting. However, during the delivery of thenegative portion 140 of thesignal 136, thevalve 66 is inhibited from conducting, thereby preventing delivery of a high frequency output signal by the .4oscillator circuit 49 at theoutput terminals 104, and 114. Since the signals from the multivibrator 96 and thecycle timer 100 are delivered concurrently to theirrespective control electrodes 94 and 98, thevalve 66 will be conductive only when positive portions of the signals and 136 are delivered to the respective control elec trodes. During the delivery of a negative signal to either of thecontrol electrodes 94, 98 ofvalve 66 thevalve 66 will be non-conducting.

FIGURE 4 schematically illustrates the envelopes ofburst signals 142 produced by theapparatus 10 with the application of the cycle timer signal 130 and the Squarewave multivibrator signal 136. The bursts of high frequency signals occur at a rate of 5 kilocycles per second determined by the frequency of the multivibrator circuit 96, and during the period when thepositive portion 132 of the cycle timer signal 130 is delivered to thevalve 66. Thus in the illustration the envelopes of burstsignals 142 are delivered during a one/half second period followed by a period of one/half second during which no burst signals of high frequency are delivered at the terminals of theapparatus 10, again followed by the delivery of aburst 142 of high frequency signal for the period of one/half second, and so on. Of course, when thefoot switch 22 is released and thereby opened, theapparatus 10 is de-energized by the removal of the high voltage signal delivered to the anode 46 of the valve 48, preventing oscillation of thecircuit 49 and delivery of output signals.

High frequency signals in the order of one magacycle per second to eight megacycles per second have been used in electrosurgery for cutting and coagulating. However, the use of such high frequency signals have resulted in burning and charring of live tissue due to the application of energy continuously over an uninterrupted period of time. It has been found by the applicant, that the application of energy in limited quantities with sufi'icient relaxation or cooling time between the application of such energy reduces damage to live tissues and greatly improves the utility of the surgical apparatus.

Thus, for example, the application of a high frequency signal to the surgical instruments connected to the terminals of theapparatus 10 over a limited period of time such as .1 second, .5 second, 1 second and 2 seconds, reduced and minimized the damage to and destruction of living tissue by charring and burning which might otherwise result from the application of continuous energy over an extended period of time.

Excellent results have been achieved by the application of the high frequency signal to the surgical instrument for a time period of .1 second followed by an 01? time period of .4 second. The above results were superior to those results achieved by the application of power over a period of .4 second followed by an off period of .1 second for providing the working cycle of signals delivered to the surgical instrument.

Improved results over the applications of continuous high frequency signal to the surgical instrument, was also achieved by delivering energy in bursts of high frequency signals which bursts occur at a frequency of 1000 bursts per second to 200,000 bursts per second. Better results, however, were achieved when the bursts of the signals were delivered during a .5 second interval followed by a .5 second interval during which no signals were delivered.

In the particular example illustrated of theapparatus 10 in FIGURE 1, the apparatus delivers the high frequency signal in bursts of 5000 bursts per second, the high frequency signal having a frequency of "4.5 megacycles per second and, with the burst being delivered in cycles of 1 second and during a period of .5 second, the remaining period being without the delivery of signals. Although in the preferred form described the bursts of high frequency signals occur at a rate of 5000 bursts per second, bursts occurring in the range of 3,000 to 7,000

bursts per second are also highly effective. Thus, in the application of the apparatus in operating upon living tissue better results have been obtained in all phases of electrosurgery, whether cutting or coagulating, when the high frequency signal is not continuously applied to the living tissue, but is applied over limited periods of time. Periods of time during which signals are not applied allow tissue to cool and prevent or limit burning or charring. The burning or charring of tissue is of great disadvantage in that the forming of seams with such charred or burned tissue materially hinders the healing process, does not minimize production of scar tissue, and reduces the strength of seams formed by the tissue in the burned or charred regions.

Thesurgical apparatus 10 is most useful in electrosurgery by minimizing charring and burning of live'tissue especially when veins which have been cut by theapparatus 10 are butted together for bonding, or when incisions are closed. Under such circumstances the use of theapparatus 10 results in stronger bond formations with less scar tissue, giving better healing and stronger seams.

When seams are produced by clamping tissue together and passing current from theapparatus 10 through the adjacent tissues to form a coagulum, the operation of theapparatus 10 provides energy over limited periods of time by use of the bursts of signals of high frequency, and the application of such bursts over a limited time, also results in minimizing the burning and charring of the tissue to be seamed and results in stronger seams with less scar tissue formation.

A most important use of theapparatus 10 is for transplanting organs. Theapparatus 10 when used to surgically remove the transplanted organ from its origin, produces a minimum of charring and burning when the organ is removed electrosurgically by cutting. When the organ is replaced in the new location and clamped in position for forming seams, theapparatus 10 provides current which is passed through the seam region for producing the coagulum for securely bonding the organ in its new location.

Refer to FIGURE 5 which schematically illustrates asurgical apparatus 144 which is a modification of theapparatus 10 shown in FIGURE 1.

Theradial frequency oscillator 146 produces the high frequency signal in the range of 1 to 8 megacycles per second, which is delivered to itsoutput line 148. The signal from theoscillator 146 is delivered over theoutput line 148 to the input of a gate circuit 150, a cycle timer 152 delivers an output gating signal overline 154 to, theinput 156 of gate 150, while a multi-vibrator circuit158 delivers an output signal over line 160 to theinput 162 of gate 150. The cycle timer 152 may be set to deliver an output gating signal overline 154 having a duration of .1 second to 2 seconds, while the multi-vibrator 158 may deliver an output gating signal having a frequency of 1000 to 200,000 cycles per second. Upon the concurrent delivery of gating signals over thelines 154 and 160 from the cycle timer 152 and multi-vibrator 158, the gate 150 is conditioned for delivery of output signals from theoscillator 146 received online 148 to itsoutput line 164 connected to theoutput terminal 166.

Thus, by setting the cycle timer for the duration or period during which bursts signals are being delivered, bursts of signals having a repetition rate determined by the frequency of the output signal from the multi-vibrator 158 are delivered during such set period to the terminal 166 for application in electrosurgery. Thus, although theoscillator 146 operates continuously to generate the high frequency signal delivered on theoutput line 148, the gate 150 controlled by the cycle timer 152 and multi-vibrator 158 allows the delivery of the output signal from theoscillator 148 to theoutput terminal 166 only during predetermined continuous periods and in bursts at a predetermined rate of occurrence.

It will, of course, be understood that the description and drawings, herein contained, are illustrative merely,

and that various changes and modifications may be made in the structure disclosed without departing from the spirit of the invention.

What is claimed is:

1. A surgical apparatus for treating live tissue by cutting, coagulating, dissicating and/0r bonding same comprising means for generating a high frequency signal for use in electrosurgery, means for providing said high frequency signal in a plurality of signal bursts of substantially constant amplitude occurring at a frequency less than the frequency of said high frequency signal and between 1000 bursts per second and 100,000 bursts per second, and surgical means for applying said signal to a region to be treated.

2. A surgical apparatus for treating live tissue by cutting, coagulating, dessic-ating and/or bonding same comprising means for generating a high frequency signal having a frequency between 1 megacycle per second and 8 megacycles per second, means for providing said high frequency signal in a plurality of signal bursts of substantially constant amplitude occurring at a frequency less than the frequency of said high frequency signal and between 1,000 bursts per second and 100,000 bursts per second, and surgical means for applying said signal to a region to be treated.

3. A surgical apparatus for treating live tissue by cutting, coagulating, dessicating and/or bonding same comprising means for generating a high frequency signal having a frequency between 3 megacycles per second and 6 megacycles per second, means for providing said high frequency signal in a plurality of bursts of substantially constant amplitude occurring at a frequency less than the frequency of said high frequency signal and between 3,000 bursts per second and 7,000 bursts per second, and surgical means for applying said sign-a1 to a region to be treated.

4. A surgical apparatus for treating live tissure by cutting, coagulating, dessicating and/or bonding same comprising means for generating a high frequency signal having a frequency of approximately 4.5 megacycles per second, means for providing said high frequency signal in a plurality of bursts of substantially constant amplitude occurring at a frequency of approximately 5,000 bursts per second, and surgical means for applying said signal to a region to be treated.

5. A surgical apparatus for treating live tissue by cutting, coagulating, dessicating and/or bonding same comprising first means for generating a high frequency signal of between 1 to 8 megacycles per second of substantially constant amplitude for use in electrosurgery, second means providing a timing cycle having first and second periods and delivering said high frequency signal during the first period of said timing cycle and preventing the delivery of said high frequency signal during the second period of said cycle, and surgical means for applying said signal to a region to be treated.

6. The apparatus ofclaim 5 in which said second means has a timing cycle equal to or less than 2 seconds.

7. The apparatus ofclaim 5 in which the first period of the cycle of said second means has a duration equal to or less than the duration of said second period.

8. The apparatus of claim 7 in which said timing cycle of said second means is equal to 1 second and said first and second periods are each equal to .5 second.

9. A surgical apparatus for treating live tissue by cutting, coagulating, dessicating and/or bonding same comprising first means for generating a high frequency signal for use in electrosurgery, second means providing a plurality of signal bursts of substantially constant amplitude of said high frequency signal, third means delivering said bursts of said high frequency signal during a limited period of time, and surgical means for applying said signal to a region to be treated.

10. The apparatus of claim 9 in which said third means delivers said bursts of said signal for a continuous period of time which is equal to or less than 2 seconds.

11. The apparatus of claim 9 in which said third means delivers said bursts of said signal for a continuous period of time which is equal to or less than 1 second.

12. The apparatus of claim 11 in which said third means delivers said bursts of said signal for a continuous period of time which is equal to or less than .5 second.

13. A surgical apparatus for treating live tissue by cutting, coagulating, dessicating and/or bonding same comprising first means for generating a high frequency signal for use in electrosurgery, second means providing a plurality of signal bursts of substantially constant amplitude of said high frequency signal, third means providing a timing cycle having first and second periods and delivering said bursts of said high frequency signal during the first period of said timing cycle and preventing the delivery of said high frequency signal during the second period of said cycle, and surgical means for applying said signal to a region to be treated.

14. The apparauts of claim 13 in which said second means provides said high frequency signal in a plurality of bursts occuring at a frequency less than the frequency of said high frequency signal and between 1000 bursts per second and 100,000 bursts per second, and said third means has a timing cycle equal to or less than 2 seconds.

15. The apparatus ofclaim 14 in which said first means provides said high frequency signal with a frequency between 1 megacycle per second and 8 megacycles per second, and said first period of the cycle of said second means has a duration equal to or less than the duration of said second period.

16. The apparatus of claim 15 in which said first means provides said high frequency signal with a frequency between 3 megacycles per second and 6 megacycles per second, and said second means provides said high fre quency signal in a plurality of bursts occuring at a frequency between 3,000 bursts per second and 7,000 burts per second.

17. The apparatus ofclaim 16 in which said first means provides said high frequency signal with a frequency of approximately 4.5 :megacycles per second, said second means provides said high frequency signal in a plurality of bursts occurring at a frequency of approximately 5,000 bursts per second, and said timing cycle of said second means is equal to 1 second and said first and second periods are each equal to .5 second.

References Cited UNITED STATES PATENTS 2,622,200 12/1952 Hodgson 128-423 XR 3,127,895 4/1964 Kendall et a1. 128422 2,238,344 4/1941 Schuler et al 128303 2,835,254 5/1958 Coles 128--303 2,993,178 7/1961 Burger 128-303 3,077,884 2/1963 Batrow et a1 128-423 WILLIAM E. KAMM, Primary Examiner U.S. Cl. X.R. 128303.17

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