DE3045996A1 - Electro-surgical scalpel instrument - has power supply remotely controlled by surgeon - Google Patents

Abstract

The electro-surgical scalpel has two switches on the hand held instrument which enable the surgeon to remotely increase or decrease the output of the power supply. This may be achieved by electro-mechanical or electronic means. When one of the two switches (K1, K2) on the hand held instrument is closed, a reversible motor (M) drives the slider of the potmeter (R) in the power supply forward or backward, thus controlling the current supply to the instrument. Alternately, closing one of the switches generates a ramp voltage which controls the internal resistance of a semiconductor device.

Description

ELECTRICAL SURGERY DEVICE

The invention relates to an electrosurgical device with a switch for the operating modes ~ monopolar "and" bipolar "and with another one in the operating mode "monopolar" effective switch between the operating modes "cut" and "coagulate", as well as with at least one adjustable resistor for setting the output power in the respective operating mode, with one output connection in the case of monopolar operation of the device via the plate electrode with the patient's body and the other Output connection with a so-called active electrode to be handled by the surgeon is connected and in bipolar mode both output ports with two of the Surgeons handle electrodes, preferably as forceps with one another isolated branches are formed, are connected.

Such electrosurgical devices, which are predominantly in semiconductor technology are built are known. They essentially contain a generator that Generates a frenzy of a few hundred kilohertz, usually only in the operating mode "coagulate" effective modulator, a power or final amplifier and various Safety and warning circuits to prevent operating errors. In the operating mode "Cut" is worked with a relatively high output power a constant arc transition between the active electrode and the tissue has the consequence, so that this with the correspondingly designed electrode as with can be severed with a scalpel. In the "coagulate" operating mode high-frequency output signal of the generator by means of the modulator in pulses with a duration for example 10 / t £ and a pause of for example 40 jts converted and at the same time the output power is reduced. These Operating mode is preferably used to close blood vessels.

If necessary, a mixed operating mode "cut / coagulate" is also possible possible with the one with a longer pulse duration, a shorter pulse pause and compared to the coagulate operating mode, increased output power is used.

As for the various possible uses of the electrosurgical device very different output powers are required, the power is between a minimum value close to zero and a maximum value that is several hundred watts can be adjustable. The setting is usually made for the individual operating modes Via separate potentiometers or step switches, for example the level of the supply voltage of the power amplifier. This supply voltage is used for this purpose in a power supply unit taken with adjustable or at least controllable output voltage. The circuit techniques for such network devices are known and therefore do not need any details here to be explained. To give just one example, the power supply unit can have a Phase control circuit with a thyristor or triac included, the firing angle depending on the setting of the potentiometer or step switch changes.

For safety reasons, especially to avoid burns, becomes the output voltage of the device to the electrode to be handled by the surgeon (in monopolar operation) or to the electrodes (in bipolar operation) only for so long created as it is actually needed. This can either be via a momentary contact trained foot switch to be operated by the surgeon or via a similar, built into the electrode holder and handle and used by the surgeon with the finger to be actuated button happen. Pressing the Foot switch or the finger switch then triggers via one contained in the electrosurgical unit Auxiliary circuit, the oscillation of the generator off or in another way leaves the high-frequency output voltage of the device reach the electrodes.

According to the different physiological effects of the between the electrodes in the operating modes "cut" and "coagulate" the flowing current there is often the need to switch between these operating modes several times. There are already double foot switches or double finger switches for remote controlled switching known that when one contact is actuated the device e.g. in the operating mode "cut" with the preset output power and when the other is activated Contact the device in the "coagulate" operating mode with the preset Activate performance. Receives the feedback about the respectively activated operating mode the surgeon optically through different colored signal lamps and / or acoustically in Form of different high notes.

During an operation in which a wide variety of tissues are severed must, however, not only have to be repeated several times between the two operating modes mentioned to be switched, but it is often used for best results as well it is necessary to change the output power set in the respective operating mode. In the previously known devices this requires an ilfserso, which according to Instruction of the surgeon the output power of the device in the respective operating mode changes. Direct operation of the device cannot be expected of the surgeon himself as the operating field requires his full attention. Independent of From this point of view, however, the surgeon is also keen to operate the device not possible because the electrosurgical unit is normally used during an operation is in the non-sterile area. The fact that, therefore, solely for the setting the Output power of the electrosurgical unit partially uninterrupted over several An operator is required for hours, to whom the surgeon continuously instructs grant and the execution of which he has to supervise, proves to be extraordinary unsatisfactory, especially as this also increases the surgeon's ability to concentrate is used.

The invention is therefore based on the object of an electrosurgical device of the type mentioned at the outset to create its output power from the surgeon is remotely controllable.

This object is achieved according to the invention in that the value of the the output power of the device determining resistance by actuating a first, placed in the handle of the electrode (s) to be handled by the surgeon and with the device electrically connected contact can be enlarged and operated a second, similar contact can be reduced in size.

This solution has the advantage of providing the previously necessary helper Adjustment of the output power of the device to make unnecessary, so that the output power of the electrosurgical device can be set remotely directly by the surgeon.

This also eliminates the previously unavoidable time delays and operating errors due to hearing impairments or other misunderstandings between the surgeon and the assistant.

The claims 2 and 3 relate to developments of the device that the Surgeons can immediately see which output power has been selected or set Has.

The basic idea of the invention can be both electromechanical as well as electronically, in the latter case either in analogue or in digital Realize circuit technology.

Claims 4 and 5 relate to electromechanical solutions.

Claim 6 relates to an embodiment in analog circuit technology.

Claim 7 relates to an embodiment in mixed form digital / analog circuit technology.

A particularly preferred embodiment in purely digital circuit technology is specified in claim 8.

Claims 9 to 15 relate to further developments and advantageous refinements directed to these embodiments.

The electrosurgical device according to the invention is based on the following the drawing explains in the various embodiments in the block diagram are shown. It shows: FIG. 1 - a simplified representation of an electrosurgical device according to the prior art Figure 2 - a circuit diagram to explain the basic idea of the invention, Figure 3 - a first embodiment of an electromechanical remote control circuit, Figure 4 - an embodiment of a circuit for acoustic signaling and for the visual display of the set output power, Figure 5 - a second Embodiment of an electromechanical remote control circuit, Figure 6 - an embodiment an electrical remote control circuit that works essentially analogously, FIG 7 - an embodiment of a digital / analog operating remote control circuit figure 8 - another embodiment of an essentially digital remote control circuit, FIG. 9 - an embodiment of the digital circuit according to FIG. 8 in connection with an optical and an acoustic display, Figure 10 - a simplified circuit diagram a digital circuit for the remote control of an electro-surgical device with rnehrercn fletriebqnrten.

The electrosurgical device shown in Fig. 1 according to the prior art Technology essentially consists of a high-frequency vibration generating Generator 1, which is followed by a controllable modulator 2, to which a likewise controllable final or power amplifier 3 follows. At the outputs 4, 5 are different, Treatment electrodes, not shown, can be connected.

Such an electrosurgical device is usually between the modes of operation monopolar and "bipolar" switchable as well as in the operating mode "monopolar" between the operating modes cut and "coagulate" switchable. In every operating mode the output power of the device can be set separately.

For switching between monopolar and bipolar operating modes A switch S 1 is used to switch between the operating modes and cut A switch S 2 is used to "coagulate". The switch S 2 can not be shown in any more detail Can be operated by the surgeon via a foot switch or a finger switch. The contacts of the switches S 1, S 2 are interconnected in such a way that on the one hand the modulator 2 via its control inputs 2a and 2b that of the respectively selected operating mode receives corresponding control signal and that on the other hand for each operating mode separate potentiometer Rs, Rk, Rb for setting the output power of the device works effectively. In the present case is the respective potentiometer according to the position of switches S1, S2 at the control input of a power supply unit 6, which supplies the supply voltage for the output amplifier 3 via its output 6a, so that the amplitude of its high-frequency, possibly pulse-modulated by the modulator 2 Output signal at the outputs 4.5 approximately proportional to the output voltage of the Power supply 6 is. The output voltage of the power supply unit 6 is for its part approximately proportional also on the relevant potentiometer, in the illustrated case on the potentiometer Rs, set resistance value.

The control of the output power can of course also be 1 ri realized in another way, zzr. also replaced by an appropriate regulation at which the resistance value set on the relevant potentiometer works as a setpoint encoder. The input variable controlling the power supply unit 6 can both directly the resistance value as well as one proportional to the set resistance value Be a current or a proportional voltage.

The control of the modulator 2 is only shown schematically here and can be designed, for example, so that the modulator 2 then if Control input 2a in the operating mode corresponding to the switch position shown "cut" is placed on ground, is ineffective, so the high-frequency generator signal no modulation is impressed, that the modulator 2, however, a pulse modulation generated in any other operating mode, namely when its input 2b is at ground lies.

The modulator 2 can of course also have additional control inputs have, e.g. mix for an operating mode that basically corresponds to the "cutting" operating mode corresponds, however, the high-frequency signal is also pulse-modulated, with a longer pulse duration than in the coagulate operating mode.

Because of the strict safety regulations applicable to electrical medical devices, but also because an unintentional activation of the outputs 4,5 connected Electrodes or an activation in one for the concerned Use case unsuitable mode of operation to severe burns to the patient or the surgeon, the usual electro-surgical devices contain one Series of safety and indicator circuits, with the exception of switch S3 are not shown in the control line of the output amplifier 2. When the Switch S3 has no signal at outputs 4, 5.

The switch S3 is usually operated remotely by the surgeon, and either via a foot switch or a finger switch, each are designed as momentary contact. The momentary contact can also be made with the remote control for S 2 be combined to a double foot switch or a double finger switch, one switch of the "cut" mode and the other switch is assigned to the operating mode coagulate and each time the one is actuated or the other switch at the same time the switch S 3 is closed.

In addition to this remote-controlled operating mode switchover and Activation of the electrodes, for the reasons given in the introduction, it is desirable to be able to adjust the output power of the device remotely. In turn for safety reasons, however, the relevant potentiometer Rs, Rk or Rb set, upper limit value of the output power not exceeded can be. According to the basic concept of the invention shown in FIG. 2 the surgeon does this via two momentary contacts K 1 and K 2, which are also used as foot switches or designed as a finger switch and via a line L with a circuit 7 are connected within the electrosurgical device, which at their outputs 8,9 supplies a resistance value R which increases continuously or gradually as long as the contact K 1 is closed, but decreases as long as the contact K 2 is closed is and remains constant as long as both contacts are open, and preferably and for safety reasons remains constant even if both contacts are at the same time be pressed. The resistance value appearing at the outputs 8 and 9 of the circuit 7 is then used to control the output power of the electrosurgical unit used. For the following description, it is assumed that this control according to the embodiment is realized in FIG. Provided that the output power increases with The value of the potentiometer Rs, Rk or Rb that is active in each case increases, the condition is that the output power is that preset on the potentiometer in question Value must not exceed, fulfilled by the fact that the output 8 of the circuit 7 is connected to the control line of the power supply unit 6 in Fig. 1 at point I and the output 9 of the circuit 7 is connected to ground. Provided the reverse is true between the resistance value set on the respective potentiometer and the Output power, a series connection is used instead of this parallel connection used so that R then between points I and II in the control line of the Power supply unit 7 is.

Fig. 3 shows a first embodiment with a direction reversible Servomotor M, which adjusts a potentiometer R. The two fixed contact pieces the contacts K 1, K 2 are connected to one terminal via an alternating voltage source 10 of the motor M connected, the other connection via two oppositely polarized diodes D 1, D 2 with the two movable contact pieces of the contacts K 1, K 2 in connection stands. When the contact K 1 is actuated, the motor M receives the positive half-waves the voltage supplied by the voltage source 10 and rotates in one direction, when contact K 2 closes, the motor is operated with the negative half-waves and runs in the opposite direction of rotation.

In the event of a remote-controlled change in the output power of the device is at least qualitative, but preferably also quantitative at the same time The surgeon is required to display the output power that has just been set. A direct tap from the output of the electrosurgical device is not straightforward possible, since this output via the switch S 3 (Fig. 1) only briefly is activated. An acoustic and visual display circuit that has a constant Information about the provides the set output power is shown in FIG.

This is based on an analog signal that is proportional to the remote-controlled set resistance value R. One easy way To obtain such an analog signal, there is the one shown in FIG. 3 Circuit then that. the motor M in addition to the potentiometer R. and synchronously with this another R 'adjusted, its connections between ground and a voltage + U lie and its wiper thus corresponds to the set resistance value R supplies proportional voltage uR. This voltage uR is the control input of a voltage controlled oscillator 11 and the first input of an analog multiplier 12, the second input of which is connected to the output of a tone generator 13 is.

A loudspeaker 14 is either connected to the output via a switch S 4 of the voltage controlled oscillator 11 or the output of the analog multiplier 12 connectable. In the first case, the loudspeaker 14 delivers an acoustic signal, whose pitch changes proportionally to the set output power, in the second If the loudspeaker 14 emits a sound signal, the volume of which is proportional to Output power of the device is.

The input power is still on a 7-segment display 15 digital as well as via a line of LEDs 16 analog in dimensionless units, e.g. from 0 - 10, can be displayed. The voltage continues to be parallel to the inputs on the one hand a decoder and driver circuit 17 for the 7-segment display and on the other hand a decoder and driver circuit 18 for a so-called bar graph, i.e. a line of LEDs that look like the known LED level indicators works, fed. The corresponding circuits are known to the person skilled in the art.

In Fig. 5 is another electromechanical solution for the remote control shown. The contacts K 1 and K 2 are connected to the relay windings A 'and A des Relay of a reversible stepping mechanism connected, between its fixed contact pairs aO up to an * 1 a moving contact a step by step movable is, each actuation of the contact K 1 a displacement step in one Direction, each actuation of the contact K 2 a shift in the other direction causes.

The contact pairs aO to an + 1 are parallel between ground and the Partial resistors R 1 to Rn of a resistor chain, the first resistor R 1 with point I of the circuit according to FIG. 1 and its last resistor Rn with ground connected is. The adjustable resistance value is therefore the sum of the respective Partial resistances are formed in the cable run. The described stepper mechanism thus plays the role of circuit -7 in FIG. 2.

Fig. 6 shows a further embodiment of the circuit 7 according to Fig. 2. The contacts K 1 and K 2 control a staircase voltage generator 19, whose output is connected to the base of an npn transistor 20, whose Collector / emitter path has the role of - in this case gradually - changeable Resistance value R plays. Functionally corresponds to the staircase voltage generator 19 the stepping mechanism according to FIG. 5, the collector / emitter path of the transistor 20 of the resistance chain in Fig. 5. The relationship between the passage resistance of the transistor 20 and the step-shaped control current applied to its base can be linearized by known circuit measures. Instead of the bipolar Transistor 20 can also be a field effect transistor used directly is controllable with the output voltage of the staircase voltage generator 19 and the Advantage of a higher linearity of the relationship between the control voltage and the forward resistance of its source-drain path. The staircase voltage generator 19 contains a clock that the output voltage step by step in the specified Cycle increased by a fixed amount as long as contact K 1 is pressed, however, reduced as long as the contact K 2 is pressed.

While the circuit shown in Fig. 6 works largely analog, 7 shows an embodiment with largely digital operation. The contacts K 1 and K 2 are here with the control inputs one Digital circuit 21 connected, which än its output a digital, e.g. BCD-coded Signal or data word generated, the value of which increases as long as contact K 1 is pressed the value of which, however, decreases as long as contact K 2 is pressed. This Data signal is fed serially or in parallel to a digital / analog converter 22, whose output signal is the forward resistance of a semiconductor 23, in the exemplary embodiment again an npn transistor, controls.

When the contacts K 1, K 2 are open, the corresponding inputs are located the digital circuit 21 via the resistors r to the voltage + U, thus obtained the logic level H. When one of the contacts closes, the relevant input connected to ground and is therefore at the logic level L.

Fig. 8 shows a modification of this embodiment in which the digital circuit 21 is followed by a decoder 23, which is that of the digital circuit in the BCD code with 8 it delivered data word decoded and one to the respective digital value at its input corresponding signal distribution at its outputs B 1 to B 8 supplies. Each of these outputs is connected to the base of an associated transistor T. 24 to T 32 connected. Each of these transistors controls a relay A1 to A8. the associated relay contacts a1 to a8 are parallel to the partial resistors R1 to R8 of a resistance chain, the base of which is on ground, while its upper Terminal is connected to point I of the circuit of FIG. The values of the Partial resistances follow the geometric series 2, 4, 8 ..., 2n> so that the relationship the following applies: R8: 2 # x R7; ...; R2 = 2 x R1. The decoder 23 thus sets that of the digital circuit 21 delivered 8-bit data word, which can therefore assume 256 values, in this Data word corresponding resistance value, namely by composing this Resistance value from the relevant partial resistances R1 to R8.

In principle, the transistors T 24 to T 32 and the associated Relays A1 to A8 with contacts ° -1 to o8 can also be replaced by optocouplers. The latter, however, are opposite EIF irradiation and others, in Interference voltages generated by the electrosurgical unit are more sensitive than relays.

9 shows an exemplary embodiment for the digital circuit 21.

It consists of an 8-bit up / down counter that is attached to his The output supplies a BCD-coded data word corresponding to the count reached, via a data bus DB on the one hand to the decoder 23 (see FIG. 8) and on the other hand the D / A converter 22 (see. Fig. 7) is fed, its analog, the set Resistance value corresponding output voltage uR of an optical display 25 and an acoustic display 26 is supplied. Both displays can be used accordingly Fig. 4 be executed. Alternatively, the visual display can also be used directly be connected to the data bus DB, for a display in dimensionless Relative values e.g. from 0 to 10 an evaluation of the more significant nibble as well as the use of a 1 1/2 digit 7-segment display is sufficient. Corresponding integrated Circuits are customary in the trade.

The reset input of the counter 24 has a not shown in detail Circuit connected with each change in the operating mode of the electrosurgical unit a reset pulse R delivers.

The clock input of the counter 24 is connected to a clock generator 27. The "up" input for the "up" counting direction is connected to contact K 1. The down input for the "down" counting direction is connected to contact K 2. The clock input is enabled when either the input is up or the input down when the assigned contact K 1 or K 2 is closed, assume the L state. The counter then counts from the last reached and saved counter reading up or down until the relevant contact opens again. The counter reading reached is consecutive as a data word in BCD code or in any other suitable code delivered to the data bus DB. Resetting the counter 24 to 0 with every change operating mode prevents the electrodes from being unintentionally applied with too high a namely / the count reached in the previous operating mode appropriate Output power can be activated. This case can happen very easily, though the cutting mode is switched to the coagulating mode, because in the first case it is regularly with a considerable, possibly more worked as twice the output power than in the latter case. However, resetting the counter each time the operating mode is changed has the Disadvantage that the output power through each time in the new operating mode Actuation of contact K 1 from a value close to zero to the required one Operating value must be brought.

The circuit shown in FIG. 10 avoids this disadvantage.

They are attached to their remote control inputs E 1 and E 2 for reasons of space Contacts K 1 and K 2, no longer shown, are connected, in the actuated state connect the relevant input to ground, i.e. the one generated via the resistors r Change idle state H to state L. To the operating mode message inputs E3 to ES switches S1 and S2 (Fig. 1) are connected with auxiliary contacts (not shown), which change the state of the relevant input from H to L if the associated: #operating mode is switched on or switched to this.

The circuit essentially comprises a # 8-bit counter Z and for each operating mode has a D flip-flop FF1 to FF3 and an associated data memory M I to M III. Depending on the logic state at its controlling inputs the counter counts the pulses of the clock generator 27 and gives the respective reached Counter reading via its output Dout as a data word on the data bus DB 1. With On the one hand, a counter end value logic 28 is connected to the data bus, which prevents that the maximum possible count of 256 with an 8-bit counter has been exceeded and the counter Z thus works as a ring counter; still has the data bus DB 1 a connection for the decoder 23 (Fig. 8, 9) and possibly for the D / A converter 22 (Fig. 9) and is with the data inputs D n of the memory M T bis M III connected. Their data outputs are there via a further data bus D13 2 with the Data input Din of meter Z connected. The memory When changing to a new operating mode, M I to M III save the one in the previous operating mode, last counter reading reached in the form of the corresponding Data word that the counter when switching back to the previous operating mode Z is preset to the previously reached value via the data bus DB II. An incoming inspection 29 checks the logical status of the operating mode message inputs E3 to E5 for plausibility.

The circuit works as follows, assuming positive logic is and L the binary value 0, H the binary value 1: The counter Z dominates the preset condition. For Preset = H, the Up / Down input and the clock input are locked. The data word on the data bus DB2 is accepted via Din.

Preset = L locks Din and gives DoUt as well as the clock input and the Up / down input free. In the latter case, L means counting up, H means counting down. In the memories M I to M III, L leads to the release of Dort, M at input Dis to Dis to block Dout L at input St blocks D / Din, H to St leads to takeover of the data word via Din in the memory.

L at one of the inputs of the input control 29 leads to H at the associated output Q2 to Qq. Output Q1 is only high when no more than one input is on L. All other input states lead to L at Q1 In the following it is now assumed that L at E3 is the operating mode "bipolar", L at E4 mean "cut" mode and L at E5 mean "coagulate" mode. It is also assumed that the "cutting" mode was initially selected and the counter Z has reached a certain count. Now go to the mode of operation "bipolar" changed. E4 then changes from L to H, E 3 by H According to L. Since this state, like the previous state, is plausible or permissible Q1 remains at H. The AND gate connected downstream of Q 1 receives G 1 from the output Q of the unset monoflop MF at its further catch also H and leaves hence the clock signal of the clock generator 27 present at its third input through, which is thus on the clock inputs of the flip-flops FF1 and interest here FF2 reached.

Since the output Q3 of the input control 29 changes from H to L, will FF2 reset, while FF1 receives a H at its input from Q4 and is therefore set will. Its output Q changes from H to L, while at the same time the output Q changes from FF2 changes from L to H. As a result, the further data output is via Dis of M II locked. The H signal triggers via a pulse gate IG? and an OR gate G2 the monoflop MF, so that its output Q changes from H to L and thus G1 for blocks the duration of the set time for further clock pulses, while Q of MF goes to H at the same time. The output Q from MF is on the one hand via an OR gate G6 connected to the preset input of the counter Z, so that it can be used for the duration the operating mode switchover and the subsequent time until tilting back MF remains blocked for counting commands; Q from MF is still with the first inputs connected by three NOR gates G3 to G5, each of which is connected to the store input St Memory M 1 to M ITT connected upstream and with its second input with the! \ Usg.nng q of the hetrer fenden flip-flop FF1 to P7 is connected. Since the NOR gate G4 of Q now receives H from FF2, i.e. after FF2 tilts back, becomes independent of the last entered data word according to the status present at its first input saved and further data entry blocked while the same value H is on the input Dis blocks further data output.

The last counter reading in the cutting mode is thus in M II saved.

The memory M 1 assigned to the new "bipolar" operating mode receives on the other hand, a signal L now from O of FF1 at its input Dis, so that Dout is released and the stored data word via DB2 to which is in the preset state located counter Z is transferred to its presetting. Until you tip back From MF, D. from MI remains blocked, since the associated Storein input St only then changes from L to H and thus releases Din when MF tilts back and with it the level L is present at both inputs of the NOR element G3. With the tilting back of MF the presetting of Z is thus completed on the one hand and on the other hand the MI is ready to store a new data word.

Undefined or impermissible operating states with regard to the selected Operating mode closes the circuit on the one hand via the input control already mentioned 29 and on the other hand via a U2JD element G7, its three inputs with the Q outputs connected from FF1 to FF3. The output of this AND gate G7 is over the OR gate O6 is connected to the preset input of Z, so it brings the counter into the preset state when all outputs Q from FF1 to FF3 are high. This state, which does not normally occur, can, for example, after Turning on the operating voltage or due to any interference pulses. Provision has also been made that the counter reading cannot change for as long the state L does not prevail either at the input E1 or at the input E2. An exclusive NOR element G8 is used for this purpose, with inputs E1 and E2 as well as with its output is connected to the preset input of the counter via G6. Both the State H on both inputs Ei, E2 as well as state L (i.e. both contacts Kl, K2 from the previous figures accidentally pressed at the same time) change the output of G8 from L to H. The input E2 is on the one hand with the Counter end value logic 28, on the other hand connected to the up / down input of the counter Z. The counting direction "upwards" is recognized by the fact that when the preset condition is canceled E2 remains on 1I. This state is only possible when the contact Kl is pressed, i.e. with El on L, possible. The "down" counting command is reversed when it is canceled the preset condition and the state L recognized at E2.

The counter end value logic 28 compares that received from the data bus DB1 Data word with the specified lower and upper limit value and blocks when it is reached of the lower limit value and a further "downwards" counting command as well as when it is reached of the upper limit value and a further command "outwards" via an AND element G9 the clock input of the counter Z for the further clock pulses.

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Claims (15)

PATENT CLAIMS 1. Electrosurgical unit with a switch for the operating modes "monopolar" and "bipolar" and with another one in the operating mode "monopolar" effective switch between the operating modes "cut" and "coagulate", as well as with at least one adjustable resistor for setting the output power in the respective operating mode, with one output connection in monopolar operation of the device via a plate electrode to the patient's body and the other Output connection with a so-called active electrode to be handled by the surgeon is connected and in bipolar mode both output ports with two of the Surgeons handle electrodes, preferably as forceps with one another isolated branches are formed, are connected, characterized in that the value (R) of the resistance determining the output power of the device Actuation of a first electrode (s) to be handled by the surgeon in the handle housed and electrically connected to the device contact (Kl) can be enlarged and can be reduced in size by actuating a second, similar contact (K2). 2. Apparatus according to claim 1, characterized in that the resistance value (R) via an optical, digital or analog display device (15, 16) in dimensionless Units can be displayed. 3. Apparatus according to claim 1 or 2, characterized in that the set Resistance value via an acoustic, variable in pitch or volume Device (11 to 14) can be displayed. 4. Device according to one of claims 1 to 3, characterized in that that the contacts (K1, K2) in the circuit of a reversible servo motor (M) which changes the resistance value (R) by turning a potentiometer. 5. Device according to one of claims 1 to 3, characterized in that that the contacts (K1, K2) control a reversible stepping mechanism (A ', A? t), whose contacts (aO to an + i) are connected to a resistor chain (R1 to Rn) and at its output connections the resistance value dependent on its position (R) returns. 6. Device according to one of claims 1 to 3, characterized in that that the contacts (K1, K2) control an analog circuit (19) at their output supplies a DC voltage signal, the level of which increases continuously as long as the one contact (K1) is actuated, the level of which decreases continuously as long as the other contact (K2) is actuated and its level when both contacts are actuated and remains constant with non-actuated contacts, and that this analog circuit (19) a semiconductor (20) is connected downstream which the DC voltage signal at a control electrode and the one on the level of the DC voltage signal dependent on resistance which forms the adjustable resistance value (R). 7. Device according to one of claims 1 to 3, characterized in that that the contacts (K1, K2) control a digital circuit (21) at its output supplies a digitally coded signal, the value of which increases gradually as long as the one contact is actuated, the value of which decreases gradually as long as the other Contact is actuated and its value when actuating both contacts (K1, K2) and with non-actuated contacts (K1, K2) remains constant, and that this Digital circuit a digital / analog converter (22) is connected downstream, the output signal of which controls the on-resistance of a semiconductor (23) whose on-resistance forms the adjustable resistance value (R). 8. Device according to one of claims 1 to 3, characterized in that that the contacts (Kl, K2) control a digital circuit (21) at their output supplies a digitally coded signal, the value of which increases gradually as long as the one contact (K1) is actuated, the value of which decreases gradually as long as the other Contact (K2) is activated and its value when both contacts (K1, K2) are activated and with non-actuated contacts (K1, K2) remains constant, and that of the digital circuit (21) a decoder (23) is connected downstream to the partial resistors (R1 to R8) a resistor chain parallel switches (al to a8) controls, the Resistance chain the adjustable resistance value (R) in the form of resistance steps supplies. 9. Apparatus according to claim 8, characterized in that the digital circuit contains an up / down counter (2in), the counting input of which is connected to a clock (27) is connected, its input (Up / Down) for the counting command and the counting direction is connected to the contacts (K1, K2) and the digitally coded at its output Signal - preferably in the form of BCD data - delivers #. 10. Apparatus according to claim 9, characterized in that the counter (24) emits the digitally coded signal via a data bus (DB), which on the one hand with the decoder (23) to control the switches of the resistor chain and on the other hand is connected to a digital / analog converter (22), which is a digital or analog optical display (25) for the meter reading in dimensionless Values and a circuit (26) controls which a corresponding to the count in his Provides an acoustic signal that varies in amplitude or frequency. 11. Apparatus according to claim 9 or 10, characterized in that for Each operating mode of the device - a separate output is provided, which when selected of the operating mode concerned, a signal is sent to a corresponding message input (E3 to E5) of the digital circuit and that the digital circuit has a control logic contains an operating mode memory (FF1 to FF3) and a data memory associated therewith (MI to MIII), the Data inputs (Din) of all data memories (MI to MIII) with the data bus (DB1) and the data outputs (Dout) of all data memories (MI to MIII) with another, with a preset input of the counter (Z) connected to the data bus (DB2) and the operating mode memory activated in the selected operating mode is the consecutive Transfer and storage of the output data of the counter from the first data bus (DB1) into the assigned data memory as well as the continuous output of the stored Controls data via the second data bus (DB2) when changing to a new operating mode the data input and output of this data memory is blocked and if the choice is made again the same operating mode enables the output of the last saved data and at the same time the transfer of this data to the counter (Z) by brief activation whose preset input controls, as well as during the activation of the preset input keeps the data entry of the data memory blocked. 12. Apparatus according to claim 11, characterized in that the operating mode memory (FF1 to FF3) the preset input of the counter (Z) via a common monoflop (MF) drive. 13. Apparatus according to claim 11 or 12, characterized in that the Contacts (K1, K2) via an EXCLUSIVE-NOR element (G8) with the preset input of the meter are connected. 14. Device according to one of claims 11 to 13, characterized in that that the operating mode message inputs (E3 to E5) with the operating mode memories (FF1 to FF3) are connected via a plausibility check (29) which, if there is no Activation or, if more than one operating mode is activated, all operating mode memories (FF1 to FF3) resets to the initial state. 15. Device according to one of claims 11 to 14, characterized in that that the operating mode memories consist of flip-flops (FF1 to FF3), and that their Outputs (Q) via a common AND element (G7) the preset input of the counter (Z) Activate as long as none of the operating mode alarm inputs receive an operating signal (L) receives.