U.S. patent number 3,929,137 [Application Number 05/529,607] was granted by the patent office on 1975-12-30 for sonic warning for electrosurgical device.
This patent grant is currently assigned to Dentsply Research & Development Corporation. Invention is credited to Donald I. Gonser.
United States Patent |
3,929,137 |
Gonser |
December 30, 1975 |
**Please see images for:
( Certificate of Correction ) ** |
Sonic warning for electrosurgical device
Abstract
An electrosurgical device in which high frequency electrical
energy powers a cutting electrode. Radio frequency energy is set up
in a driver coil and a driven coil mounted in a handpiece. The
driver coil energizes the driven coil to energize a surgical
electrode connected to one end of the driven coil. Sonic warning
signals indicate production of cutting, coagulating, and blended
currents.
Inventors: |
Gonser; Donald I. (Forest Park,
OH) |
Assignee: |
Dentsply Research & Development
Corporation (Milford, DE)
|
Family
ID: |
27022634 |
Appl.
No.: |
05/529,607 |
Filed: |
December 5, 1974 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
414646 |
Nov 12, 1973 |
3870047 |
|
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Current U.S.
Class: |
606/37; 606/45;
606/49 |
Current CPC
Class: |
A61B
18/1402 (20130101); A61B 18/12 (20130101); A61B
18/1206 (20130101); A61B 2018/00178 (20130101); A61B
2018/0066 (20130101); A61B 18/14 (20130101) |
Current International
Class: |
A61B
18/12 (20060101); A61B 18/14 (20060101); A61B
017/36 (); A61N 003/02 () |
Field of
Search: |
;128/303.14,303.13,303.17,303.18,422 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Michell; Robert W.
Assistant Examiner: Cohen; Lee S.
Attorney, Agent or Firm: Pearce; James W. Schaeperklaus; Roy
F.
Parent Case Text
This is a division of my copending application Ser. No. 414,616,
filed Nov. 12, 1973, now U.S. Pat. No. 3,870,047.
Claims
Having described my invention, what I claim as new and desire to
secure by letters patent is:
1. In an electrosurgical device, means for generating an
electrosurgical cutting current, a sonic warning device connected
to the means for generating the electrosurgical cutting current
including means to produce a sound signal of a selected frequency
when the electrosurgical cutting current is generated, means for
generating an electrosurgical coagulating current, a second sonic
warning device connected to the means for generating the
coagulating current including means to produce a sound of a second
and different selected frequency when the coagulating current is
generated, means for generating an electrosurgical current, the
last mentioned means including both the means for generating the
electrosurgical cutting current and the means for generating the
electrosurgical coagulating current, both sonic warning devices
being actuated when the blended current is generated, and means for
supplying each of said currents to a patient.
2. The combination of an electrosurgical device including means for
generating an electrosurgical cutting current, means for generating
an electrosurgical coagulating current, means for generating a
blended electrosurgical current, and means for supplying each of
said currents to a patient with a sonic warning device comprising a
first sonic warning device connected to the means for generating
the electrosurgical cutting current including means to produce a
sound signal of a selected frequency when the electrosurgical
cutting current is generated, a second sonic warning device
connected to the means for generating the electrosurgical
coagulating current including means to produce a sonic signal of
another and different selected frequency when the electrosurgical
coagulating current is generated, and means connecting both sonic
signal warning devices to the means for generating a blended
electrosurgical current so that both sonic warning devices are
actuated when the blended current is generated.
Description
This invention relates to an electrosurgical device. More
particularly, this invention relates to a multipurpose
electrosurgical device. The device of this invention represents an
improvement in the type of device shown in my copending application
Ser. No. 310,830, filed Nov. 30, 1972, Pat. No. 3,804,096 issued
Apr. 16, 1974.
An object of this invention is to provide a radio frequency
electrosurgical device in which a surgical electrode can be
energized by a handpiece coil connected thereto, which handpiece
coil, in turn, is energized by a driver coil coupled thereto, the
radio frequency energy being supplied through a transmission line
from a radio frequency power source.
A further object of this invention is to provide such a device
which develops both a cutting current and a coagulating current and
which provides a sonic warning signal of one frequency when the
cutting current is being produced and a sonic warning signal of a
different frequency when the coagulating current is being
produced.
A further object of this invention is to provide such a device
which also develops a blended current and which provides a sonic
warning signal which is a blend of the frequencies when the blended
current is being developed.
A further object of this invention is to provide such a device in
which radio-frequency electrosurgical current is fed to an
electrosurgical instrument through condensers in series between a
power source and the instrument, and means is provided between
condensers for bleeding of non-radio-frequency current to ground in
the event of condenser failure.
Briefly, this invention provides an electrosurgical device
including a handpiece in which a first coil and a second coil are
wound on a handpiece core. A source of radio-frequency current of
an electrosurgical frequency is coupled to one end of the second
coil and an electrode is connected to one end of the first coil.
The source of radio-frequency current is coupled to the second coil
through series connected condensers, and inductance means is
provided between condensers to bleed off non-radio-frequency
current to ground in the event of condenser failure. The power
source has means for generating cutting current, coagulating
current, and blended current. Sonic warning devices of different
frequencies sound when the cutting and coagulating currents are
being generated. A blended sound is produced when a blended current
is generated .
The above and other objects and features of the invention will be
apparent to those skilled in the art to which this invention
pertains from the following detailed description and the drawings
in which:
FIG. 1 is a view in side elevation of an electrosurgical device
constructed in accordance with an embodiment of this invention, the
device being shown in association with a fragmentary portion of a
patient on a fragmentary portion of a table, the table being shown
in section;
FIG. 2 is an enlarged fragmentary view in lengthwise section of the
electrosurgical device shown in FIG. 1, wiring being omitted for
clarity;
FIG. 3 is a plan view of a handpiece portion of the electrosurgical
device, a case thereof being broken away to reveal interior
construction;
FIG. 4 is a view in side elevation of an inner assembly of the
handpiece portion;
FIG. 5 is a view in lengthwise section of the handpiece portion
shown in FIG. 3, wiring thereof being broken away to reveal
structural details;
FIG. 6 is a view in end elevation of a cap of the device;
FIG. 7 is another end elevational view of the cap shown in FIG.
6;
FIG. 8 is a view in section taken on the line 8--8 in FIG. 6;
FIG. 9 is an exploded view of a power cable of the electrosurgical
device and end fastener elements thereof; and
FIG. 10 is a schematic circuit diagram of the device.
In the following detailed description and the drawings, like
reference characters indicate like parts.
In FIG. 1 is shown an electrosurgical device 14 constructed in
accordance with an embodiment of this invention. The device 14
includes a handpiece portion 16 and a cable connecting portion 17.
The cable connecting portion 17 is mounted on an end of a coaxial
cable 18. The handpiece portion 16 is arranged to support a
surgical electrode 19. In FIG. 1 the surgical electrode is shown in
position to perform a surgical operation on a patient 21. The
patient is shown in position on a passive electrode 22 and
supported by a table 23 which underlies the passive electrode 22.
The passive electrode 22 is provided with a lead 422.
The handpiece portion 16 (FIG. 5) includes a central tubular
electromagnetic core 24. A first or driven coil 26 is wound on the
core 24. A layer of insulation 27 overlies the first coil, and a
second or driver coil 28 is wound on the layer of insulation. A
stud 29, which is mounted in a central bore 31 of the core 24,
supports a hollow chuck fitting 32. A second stud 33 mounted in the
central bore 31 supports a hollow receptacle sleeve fitting 34. A
hollow sleeve 36 of dielectric material surrounds the receptacle
sleeve fitting 34, the coils 26 and 28, and the chuck fitting 32
with chuck jaws 37 of the fitting 32 extending outwardly thereof.
The surgical electrode 19 can be received inside the chuck jaws 37.
A cap 39 (FIGS. 3 and 6-8) is threaded on the chuck jaws 37 and can
tighten the chuck jaws on the electrode 19. The cap 39 has a
central opening 40 through which the electrode 19 projects. One end
portion 41 (FIG. 3) of the first coil 26 is attached to the chuck
fitting 32 as by soldering so that the end portion 41 of the first
coil 26 is electrically connected to the electrode 19.
A cable connector receptacle 42 is mounted in the receptacle sleeve
fitting 34. As shown in FIG. 2, the cable connector receptacle 42
includes a central tube 43, which is supported by an insulator
sleeve 44. The other end portion 46 of the first coil 26 is
attached to the tube 43 as shown in FIG. 3. One end portion 47 of
the second coil 28 is soldered to the end portion 46 of the coil
26. The other end portion 48 of the second coil 28 is attached to
one side of a capacitor 49. The other side of the capacitor 49 is
attached to the receptacle sleeve fitting 34 by solder as indicated
at 51.
The cable connector receptacle 42 is provided with a central socket
52 (FIG. 5) which can receive a coaxial cable end assembly 53. The
coaxial cable end assembly 53 includes a body 54 (FIGS. 2 and 9),
an annular latch member 56, and an annular latch actuator member
57. The body 54 supports annular insulator members 58 and 59 (FIG.
2) inside which is mounted a contact member 61 having a head 62
which can be received inside the central tube 43 in electrical
connection therewith. A central lead 63 (FIG. 9) of the coaxial
cable 18 can be received inside a socket 64 (FIG. 2) in the contact
member 61 with an insulating layer 66 (FIG. 9) of the coaxial cable
18 being received inside a central bore 67 of the body 54. An end
portion of an annular conductor 68 of the coaxial cable 18 overlies
a stem 69 of the body 54 to form an electrical connection
therewith. A sleeve 71, which surrounds the cable 18, can be
advanced to the position shown in dot-dash lines at 71A to hold the
annular conductor 68 in position on the stem 69. An outer
insulation sleeve 73 forms an outer layer of the coaxial cable 18
surrounding the annular conductor 68.
The latch member 56 is threaded on the body 54 and includes latch
hooks 76 mounted on spring arms 77 which resiliently urge the latch
hooks 76 outwardly. The latch actuator 57 is slideably mounted on
the latch member 56. The latch actuator 57 includes slots 78
through which the hooks 76 extend. A sleeve 79 (FIG. 2) of
insulating material is mounted on the latch actuator member 57.
When the assembly 53 is mounted in the central socket 52, the teeth
76 extend into an annular slot 81 (FIG. 2) in the wall of the
socket 52 to lock the assembly 53 in the socket 52. When the
insulation sleeve 79 and the latch actuator 57 are moved to the
left as shown in FIG. 2, the teeth 76 are urged inwardly to cause
release of the teeth 76 from the slot 81 to permit removal of the
cable end assembly 53.
In FIG. 10 is shown schematically the wiring diagram of the device.
Alternating current power is supplied by power leads 111 and 112. A
power line radio frequency interference filter 113 including
condensers 114 and 115 and inductances 116 and 117 greatly
attenuates radio frequency feed-back to the power leads. A power
line fuse 118 is provided in the lead 111. An interlock switch 119
can be provided in the power lead 111. The interlock switch 119 is
closed during operation of the device but can be arranged to open
when a casing of the device (not shown) is opened.
Leads 121 and 122 from the power line filter 113 are connected to
poles 123 and 124, respectively, of a triple pole double throw
on-off switch 126. When the on-off switch 126 is in the position
shown (off position), the leads 121 and 122 are connected to power
a primary winding 127 of a transformer 128 to impress a low voltage
such as 4 volts on a secondary winding 129 thereof. When the on-off
switch 126 is in its other position (on position), the leads 121
and 122 are connected to a primary winding 1291 of a transformer
130 to power the transformer. A panel light 131 is connected in
parallel with the primary winding 1291 to indicate that the primary
winding 1291 is powered. A thermally activated circuit breaker 1292
in series with the primary winding 1291 protects the transformer
130. A third pole 132 of the switch 126, when in the on position,
connects leads 133 and 134 to connect one side of a heater
electrode 135 of a tetrode main power amplifier tube 136 to one
side of a first secondary winding 137 of the transformer 130, which
can be constructed to produce approximately 6 volts AC to the
heater electrode 135. A capacitor 2135 is connected between the
line 133 and ground to shunt any radio-frequency current from the
heater electrode 135. The other side of the first secondary winding
137 is connected to ground as is the opposite side of the heater
electrode 135. A fan motor 1371 is also connected in parallel with
the primary winding 1291 to drive a fan 1372 which blows air on the
tetrode 136 and other components to cool the tetrode and other
components. When the on-off switch 126 is swung to its off
position, the pole 132 connects the lead 133 to the secondary
winding 129 of the transformer 128 so that the heater electrode 135
is heated not only when the on-off switch 126 is in the on position
but also when the on-off switch 126 is in the off position. As
already pointed out, the secondary winding 129 of the transformer
128 can be arranged to deliver about four volts so that the heater
electrode 135 is heated but at a lower temperature when the switch
126 is in the off position but is maintained at a sufficient
temperature that the device will operate at once when the switch
126 is turned on.
A secondary winding 146 of the transformer 130 supplies a voltage
of approximately 2000 volts AC across leads 147 and 148 to a full
wave bridge rectifier 149 which supplies 2000 volts direct current
across leads 150 and 151. The lead 150 is connected to ground as is
a cathode 152 of the tetrode 136. The lead 151 is connected through
a plate choke 153 and a parasitic suppressor network 154 to a plate
156 of the tetrode 136 so that 2000 volts DC is impressed between
the cathode 152 and the plate 156 of the tetrode 136. A filter
condenser 157 smooths out wave form ripple from the rectifier 149.
A tapped resistor 159 and a fixed resistor 159A are connected in
series across the leads 150 and 151. A lead 158 connected to the
tap of the tapped resistor 159 supplies a positive potential
through a resistor 161 and a lead 162 to a screen grid of the
tetrode 136. A voltage of approximately 380 volts can be taken off
at the tap which is maintained on the screen grid. An appropriate
resistance 164 bleeds off screen grid current to ground. A
capacitor 166 connected between the screen grid lead 162 and ground
removes or shunts out radio frequency from the screen grid.
A section 146A of the second secondary winding 146 of the
transformer 130 is connected in parallel with a capacitor 146B to
form a tuned circuit tuned to a line input frequency, which can be
60 Hertz, to stabilize the secondary winding voltages to a
variation of approximately .+-.1% with a change in input voltage of
.+-.10% impressed on the primary winding 129. Thus, the transformer
130 is a substantially constant voltage transformer stabilizing all
the circuitry of the device.
A bias voltage for a control grid 168 of the tetrode 136 is
supplied by a third secondary winding 169 of the transformer 130. A
first lead 171 from the winding 169 is connected to ground and a
second lead 172 from the winding 169 is connected to a rectifier
173. The rectifier 173 supplies a negative potential through a
resistance 1741 and an inductance 1742 to a load 174, which is
connected to one end of a first series winding 176 of a transformer
1761. The other end of the winding 176 is connected through a
second series winding 1762 of the transformer 1761 to a lead 179
connected to the control grid 168 of the tetrode 136. A condenser
181 which is connected between ground and a junction 1743 smooths
out the wave form of the potential from the rectifier 173. A
resistance 183 connected in parallel with the condenser 181 serves
to discharge the condenser 181 when the device is turned off. The
bias voltage can be approximately -120 volts.
Oscillator circuits 184 and 186 for the device are powered from a
fourth secondary winding 187 of the transformer 130. Leads 188, 189
and 190 from the winding 187 are connected through a single pole
double throw switch 191 to a full wave bridge rectifier 192 which
supplies a DC voltage across leads 193 and 194. When the switch 191
is in the position shown, a voltage of approximately 16 volts is
supplied across the leads 193 and 194. When the switch 191 is in
its other position, a voltage of approximately 25 volts is supplied
across the leads 193 and 194. A condenser 195 connected across
leads 193 and 194 smooths ripple voltage. A resistance 1961
connected across the leads 193 and 194 discharges the condenser 195
when the device is turned off. The lead 193 is connected to ground.
The lead 194 is connected to the pole of a single pole double throw
switch 196. When the switch 196 is in the position shown, the lead
194 is connected through a short lead 197 to the pole of a single
pole double throw switch 198. The switches 196 and 198 can be foot
operated switches. The switches 196 and 198 are shown in their
normal positions. When the switch 196 is turned to its other
position, the lead 194 is connected to a lead 199. When the switch
198 is turned to its other position, while the switch 196 remains
in the position shown, the lead 194 is connected to lead 200. If
the switches 196 and 198 are both turned to their other position,
the lead 194 is connected to the lead 199, and it is impossible to
connect both the leads 199 and 200 to the lead 194 at the same
time. The lead 199 is connected to one side of a potentiometer 201.
The other side of the potentiometer 201 is connected to ground
through an adjustable resistor 202. In a similar manner, the lead
200 is connected to one side of a potentiometer 203. The other side
of the potentiometer 203 is connected to ground through an
adjustable resistor 204. Thus, when the switch 196 is advanced to
its other position, a selected DC voltage is impressed across the
potentiometer 201 and when the switch 198 is advanced to its other
position while the switch 196 remains in the position shown, a
selected DC voltage is impressed across the potentiometer 203.
A voltage between zero and the selected voltage is impressed upon a
lead 206 connected to the tap of the potentiometer 203 when the
switch 198 is in its other position and the switch 196 is in the
position shown. The lead 206 is connected through an inductance or
choke 207 to the collector of a transistor 208, which is a part of
the oscillator circuit 186. The emitter of the transistor 208 is
connected to ground. The lead 206 is also connected through
resistors 209 and 211 and a rectifier 212 to one side of a tickler
coil 213. The rectifier 212 functions to reverse bias the base of
the transistor 208 and is connected to one side of the tickler coil
213, which is excited by a tank circuit consisting of an inductance
214 and a condenser 216 coupled to the transistor 208 in which
continuous oscillation is set up by the tank circuit. The other
side of the tickler coil 213 is connected to the base of the
transistor 208. The rectifier 212 establishes the reverse bias
required by the base of the transistor 208 and is also connected to
ground through a condenser 217 which establishes the bias network
circuitry. A bias rectifier 2171 is connected between ground and a
junction between the resistors 209 and 211. The tank circuit is
connected with the collector of the transistor 208 through a
coupling condenser 218. A condenser 219 is connected between the
emitter and the collector of the transistor 208 to shunt out radio
frequency potentials. A capacitor 777 acts to provide a bypass to
ground shunt for attenuating radio frequency feed-back into the
line 206 when the oscillating circuit 186 is in operation. The tank
circuit can be tuned to oscillate at a rate of approximately 1.8
megaHertz. The oscillation is picked up by the transformer winding
1762 and the voltage thereof is multiplied by the transformer
winding and impressed by way of the lead 179 on the control grid
168 of the tetrode 136 to provide an amplified output by the
tetrode 136 of that frequency. The output of the tetrode 136 is
impressed by way of a lead 220 on an output circuit which is
coupled through condenser 221 to a tuned pie network which includes
condensers 222 and 225 and inductances 223 and 226. Right-hand ends
of the inductances 223 and 226 are connected to ground so that, if
there should be failure of the condensers 221 and 222, the direct
current output of the tetrode 136 would be drained off to ground
without danger to the patient. A take-off lead 224 which is
connected between the condenser 222 and the inductance 223 extends
to one side of a condenser 225. The other side of the condenser 225
is connected to the central lead 63 of the coaxial cable 18 and
through the cable end assembly 53 to one end of the second coil 28.
The annular conductor 68 of the coaxial cable 18 is connected to
ground. The passive electrode 22 is connected to one side of a
condenser 227. The other side of the condenser 227 is connected to
ground. Thus, a continuous radio frequency oscillating potential is
set up in the first coil 26 and in the electrode 19.
When the switch 198 is moved to its other position and the switch
196 remains in the position shown and a single pole double throw
blend switch 2341 is in the off position shown, a continuous
oscillation is impressed on the coil 28. When the switch 196 is
moved to its other position and while the single pole double throw
blend switch 2341 is in the off position shown, the oscillating
circuit 184 is energized to produce an interrupted oscillation in
the driver coil 28. The oscillating circuit 184 is generally
similar to the circuit 186 already described and includes a
transistor 237, a tank circuit inductance 238, a tank circuit
capacitor 239, and a tickler coil 240 and associated elements. A
lead 241, which is connected to the tap of the potentiometer 201,
is connected through a choke 242 to the collector of the transistor
237. Moving of the switch 196 to its other position impresses a
selected DC voltage across the potentiometer 201 and a DC voltage
between zero and the selected voltage is impressed upon the lead
241. The emitter of the transistor 237 is connected to ground. The
oscillating circuit 184 is set in operation to deliver an
oscillator frequency of approximately 1.8 megaHertz on the control
grid of the tetrode 136. The lead 199, which is connected to the
high side of the potentiometer 201, is also connected through the
pole of the blend switch 2341 to a lead 245, which is connected to
base leads of transistors 244 and 246, which form a multivibrator
circuit, through resistors 247 and 248, respectively. The collector
lead of the transistor 244 is coupled through a condenser 249 to
the base of the transistor 246 and the collector of the transistor
246 is coupled through a condenser 251 to the base of the
transistor 244. The collectors of the transistors 244 and 246 are
connected to the lead 245 through resistors 2511 and 2512,
respectively. Emitters of the transistors 244 and 246 are connected
to ground. The multivibrator circuit can be arranged to oscillate
at a rate of approximately 7000 Hertz. A lead 252 from the
collector of the transistor 244 is connected through a coupling
condenser 253 and a rectifier 2531, and a resistor 2532 connected
in parallel with the rectifier 2531, to the base of the transistor
237 so that the operation of the oscillating circuit 184 is
interrupted at a rate of 7000 Hertz to put an interrupted
oscillating potential on the control grid of the tetrode 136 and to
supply an interrupted radio-frequency oscillating potential at the
electrode 19. The rectifier 2531 and the resistor 2532 connected in
parallel with the rectifier 2531 forms a network which preserves
the wave form generated by the multivibrator circuit as it is
transmitted to the oscillator circuit 184.
An adjustable capacitor 1765 is connected between the lead 179 and
ground and can be adjusted so that it tunes with the transformer
secondary coils 176 and 1762 and with the capacitor 2172 so that
the grid input is tuned with the plate series tuned circui 222,
223, 225, and 226. Both of these circuits are tuned with the driver
input oscillating circuits 184 and 186 at approximately 1.8
megaHertz.
When the blend switch 2341 is disposed in its other or "on"
position, moving of the switch 198 to its other position while the
switch 196 is in the position shown energizes both of the
oscillating circuits 184 and 186. The oscillating circuit 186 is
energized in the same manner as already described. The lead 200,
which is connected to the switch 198, is connected through a lead
256, a rectifier 257, the blend switch 2341, the lead 245, and an
adjustable resistor 2572 to the lead 199, which is connected to the
right hand end of the potentiometer 201. The rectifier 257 prevents
unwanted cross feed between the leads 199 and 200. Both the
oscillating circuit 184 and the oscillating circuit 186 are set in
operation and an output is provided from the tetrode 136 for
energizing the electrode 19 which combines the interrupted
oscillation of the circuit 184 with the uninterrupted oscillation
of the circuit 186.
The lead 199, which is connected to the high side of the
potentiometer 201, is also connected to a sonic signalling device
271, which is constructed to produce a sound signal of a selected
frequency, which can be 2900Hz. The sonic signalling device 271 is
connected to ground through a pole 2721 of an on-off switch 272 and
a resistor 273. Similarly, the lead 200, which is connected to the
high side of the potentiometer 203, is also connected to a second
sonic signalling device 274, which is constructed to produce a
sound signal of a second selected frequency, which can be 4500 Hz.
The sonic signalling device 274 is connected to ground through a
pole 2722 of the on-off switch 272 and a resistor 276. The sonic
signalling device 271 sounds when the potentiometer 201 is
energized to energize the oscillating circuit 184 to produce a
sound signal which indicates to the user of the device that the
oscillating circuit 184 is operating. The sonic signalling device
274 similarly produces a sound signal when the oscillating circuit
186 is energized to indicate that the oscillating circuit 186 is
operating. When both the oscillating circuits 184 and 186 are
operating, i.e., when a blended current is being produced, a sound
signal is produced which is a blend of the selected frequencies. If
the user does not want sound signals, the on-off switch 272 can be
opened. The size of the resistors 273 and 276 determines the
loudness of the sound signals.
When the device is to be used, an appropriate electrode 19 is
mounted in the chuck jaws 37 (FIG. 5). The blend switch 2341 (FIG.
10) is disposed either in its other position at which a blend of
interrupted and uninterrupted oscillations is produced, or in the
"off" position shown at which only one of the oscillating circuits
184 and 186 can be used at one time. The output range switch 191 is
placed in either the position shown or in its other position. The
cable end assembly 53 (FIG. 2) is mounted inside the cable
connector receptacle 42. The main on-off switch 126 is turned on,
and the electrode 19 is moved to a position adjacent or touching
tissues of the patient 21 (FIG. 1) at a point where electrosurgery
is to be performed. The appropriate one of the foot operated
switches 196 and 198 (FIG. 9) is moved to its other position to
provide a radio frequency current flow in the coil 28 which induces
a like radio frequency oscillation in the coil 26. As the electrode
19 touches or approaches the body of the patient, an
electrosurgical action is provided at the electrode, and a return
electrical path is provided through the ancillary or passive
electrode 22.
When the electrosurgical operation is to be an ordinary or usual
cutting action, the blend switch 2341 is disposed in the position
shown (off position), and the foot operated switch 198 is moved to
its other position to set the oscillating circuit 186 in operation
and to provide an uninterrupted oscillation. If a coagulating,
dessicating, or fulgurating action is desired, the foot operated
switch 196 is moved to its other position to cause operation of the
oscillating circuit 184 and the multivibrator circuit of the
transistors 244 and 246 providing an interrupted oscillation. If a
blend of interrupted and uninterrupted oscillations is required, as
where very substantial tissue destruction is desired as in some
cutting operations, the blend switch 2341 is moved to its other or
on position, and the switch 198 is moved to its other position to
cause delivery of a blending of interrupted and uninterrupted
oscillations.
The power delivered by the oscillating circuit 184 can be adjusted
by movement of the tap of the potentiometer 201. The power
delivered by the oscillating circuit 186 can be adjusted by
movement of the tap of the potentiometer 203. The condenser 227
(FIG. 10), through which the passive electrode 22 is coupled to
ground, permits passage of radiofrequency current to permit
electrosurgical action but limits passage of lower frequency
current which might shock the patient. The condenser 49, through
which the driver coil 28 is coupled to ground, similarly permits
passage of radiofrequency current but prevents passage of lower
frequency current generated as a sub-harmonic of the radiofrequency
current to isolate the coils 28 and 26 from such lower frequency
current. The condenser 49 is disposed in the handpiece to isolate
the driver coil 28 from the outer conductor 68 of the coaxial cable
18 shield, which is at ground potential.
With the structure of this invention, a number of probe or
handpiece elements can be employed with a single power unit and
cable 18, and change of handpiece elements can be rapidly and
conveniently effected.
The electrosurgical device described above and illustrated in the
drawings is subject to structural modification without departing
from the spirit and scope of the appended claims.
* * * * *