SU1410959A1 - Electrosurgical generator - Google Patents

Abstract

The invention relates to electrosurgical apparatus and is intended to dissect and coagulate the soft tissues of the body. The purpose of the invention is to reduce injuries by preventing the outflow of deep tissue destruction during coagulation of large volumes. The generator contains power sources 1 and 2, a two-channel modulator 3, a summing diode 4, a power amplifier 5 of a key type on MOS transistors, and a leading generator. torus 6, output circuit 7, active 8 and passive 9 electrodes. During the operation, the voltage at the output of the power amplifier turns out to be amplitude-modulated pulses with a modulus cf depending on the coagulation depth set by adjusting the output voltage of the second channel of the modulator 3. The average power at the output of the device is set by adjusting the output voltage of the first modulator channel. 8 il. lO

Description

1

The invention relates to medicine, in particular to high-frequency electrosurgical generators with adjustable output power, and is intended to dissect and coagulate the soft tissues of the body, as well as to stop bleeding with high frequency currents.

The aim of the invention is to reduce patient injuries by preventing excessively deep tissue destruction during coagulation and large volumes of tissue.

The inputs of the power supply sources 1 and 2 are connected to the secondary windings of a power transformer (not shown) connected by the primary winding to an AC network of 220 V 50 Hz.

Sources 1. & 2 are designed to obtain instant and filtered voltages + 60V, with source 1 delivering a current of up to 5 A to the load,. and source 2 - up to 1 A.

The first channel of a two-channel modulator 3 is implemented on transistors 17-21 and resistor 22-regulator

Fig. 1 shows the function 5 of the output voltage of the first channel on the circuit of the device; in fig. 2 - modulator. Transistor 17 is a circuit diagram of the power supply source - CTBZOB along with transistors 18-20 or the first channel of the modulator; on type KT827A, a composite emitter is formed; 3 is a circuit diagram of a power source repeater of the above-mentioned power supply unit pitank of the second modular channel 20 with an adjustable voltage on paj in fig 4 is a circuit diagram of the modulator; in fig. 5 is a circuit diagram of a high frequency power amplifier; in fig. 6 - driving frequency generator; Figs 7-25, whereby the voltage drop across the power supply diagram of the terminals of these transistors is aligned with the high-frequency power amplifier stage; FIG. 8 is a diagram of the output high-frequency voltage of a high-frequency power amplifier often-30 transistor. Emitter follower, you. Capacitor 29 provides additional power. The device consists of power supply sources 1 and 2, the outputs of which are connected to the inputs of the first

the emitter of the transistor 20. A KT816G type transistor 21 with a chain of resistors 23-25 creates an automatic bias on the bases of transistors 18 and 19.

The first channel of the modulator can deliver a current of up to 5 A to the load. Resistors 26–28 ensure the normal operation of a hundred-fold filtering of the output voltage of the first channel. Resistor 30 -. bit. First channel output

and the second channels of the modulator 3, Per-, is the emitter of the transistor 20, the second and second channels of the modulator 3 connected to the anode of the summing diode 4.

the output of the diode are in series, the output of the first channel of the modulator 3 is connected to the anode of summing diode 4, and the output of the second channel of modulator 3 is connected to the cathode of summing diode 4. The cathode of diode 4 is also connected to the input V of amplifier 5 of power connected to the excitation inputs of the power amplifier 5; the high-frequency output of the power amplifier 5 through the output circuit 7 is connected to the active 8 and passive 9 electrodes

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45

connected to the anode of the summing diode 4.

The second channel of the modulator 3 consists of a modulating pulse generator made on a K155LAZ type chip 31, a power amplifier of pulses on a KT361B type transistor 32, a KT825G type switching transistor 33, a KT827A type emitter follower and KT827A type 35 emitter follower regulating the amplitude of the output voltage of the second channel.

Resistors 37 39 and capacitors 40 - 42 determine the time pair of the power supply 1 (Fig. 2) consists of modulating pulse meters. Output

from the rectifying bridge to the diodes of the pulse generator through the current of 10, - 13 type KD206A and the filtering tangent resistor 43 is connected to

the capacitor 14. base amplifier transistor 32.

Amplifier load serves as primary

Power supply 2 (FIG. 3) is made; the transformer winding 44, is complete in a similar pattern and consists of a rectifying bridge 15 of the type KTS405V and a filter capacitor 16,

ferrite core. Resistor 45 closes transistor 32 in the pauses between the modulating output voltage of the first channel of the modulator. The KTBZOB type transistor 17, together with the KT827A type transistors 18-20, form a composite emitter repeater of higher power with variable voltage. Due to this, the voltage drop across these transistors is evened out and the emitter follower repeater, the capacitor 29 provides an additional transistor. 21 types KT816G with a chain of resistors 23 - 25 create an automatic bias on the bases of transistors 18 and 19.

the output voltage of the first channel of the modulator. The KTBZOB type transistor 17, together with the KT827A type transistors 18-20, form a composite emitter follower with adjustable voltage and, as a result, the voltage drop across these transistors is evened out and the emitter follower voltage, the capacitor 29 provides an additional channel modulator load current up to 5 A. Resistors 26-28 ensure the normal operation of cell-wide filtering of the output voltage of the first channel. Resistor 30 -. bit. First channel output

is the emitter of transistor 20,

connected to the anode of the summing diode 4.

The second channel of the modulator 3 consists of a modulating pulse generator made on a K155LAZ type chip 31, a power amplifier of pulses on a KT361B type transistor 32, a KT825G type switching transistor 33, a KT82PO type transistor 34 and a KT827A type transistor 33 and a resistor 33. regulating the amplitude of the output voltage of the second channel.

Resistors 37 39 and capacitors 40 - 42 determine the timing parameters of the modulating pulses. Output

the winding of the transformer 44 is complete

ferrite core. Resistor 45 provides the locking of the transistor 32 in the pauses between the modulating pulses. The secondary winding of the transformer 44 through the current-limiting resistor 46 is connected to the base transition of the switching transistor 33. Resistors 47 - 49 ensure the normal operation of the composite emitter follower on transistors 34 and 35. The capacitor 50 provides additional filtering of the voltage on the emitter of transistor 35. Resistor 51 - bit.

The second channel is connected in series with the first path through the emitter of the transistor 20 with the lower ends of the resistors 36 and 51 according to the scheme. Thus, the voltage at the output of the second channel is not regulated from zero, but from the value of the voltage across the transistor 20, i.e. on the voltage value at the output of the first channel.

Dual switch 52 serves to connect the slider of resistors 36 and 22 to the bases of transistors 34 and 17, respectively.

The modulator 3 is designed to receive independently controlled voltages of the first and second channels, which, after adding on the summing diode 4, form the supply voltage Vfjj of the terminal stage of the power amplifier 5.

The power amplifier 5 (Fig. 5) consists of a transistor 53 and 54 pre-amplifier type KG 361B and 55 and 56 type KG 921 B, connected according to a two-stroke amplification circuit with a load in the form of the primary winding of the transformer 57. The preamplifier inputs are connected with antiphase .coding master oscillator 6. Resistors 58 and 59 together with capacitors 60 and 61 form the input differentiated control circuit. Resistors 62 - 64 set the operating mode of the first cascade of the preamplifier, and resistors 65 67 - the operating mode of the second cascade of the preamplifier. Resistors 68 - 69 are modal in the base circuits of transistors 55 and 56. Capacitor 70 is a preamplifier that filters in the power supply circuit.

The secondary windings of a transformer 57, made on a ferrite core, are connected via gate resistors 71 g 74 between the gates and sources of transistors 75–78 of type K11904A

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terminal amplifier power performed by the key scheme. Resistors 79 - 82 balance the input resistance of field-effect transistors 75 - 78. The load on the terminal stage is the transformer primary winding.

83, ferrite on ferrite core. The secondary winding of the transformer 83 through the output circuit 7 is connected to the active electrode 8 and the passive electrode 9. The cathode of summing diode 4 is connected to the input of the final power amplifier.

The power amplifier 5 is designed to obtain a high-frequency voltage IJgbijc modulated in amplitude in accordance with the law of voltage variation of the power supply of the terminal stage of the power amplifier U.

The master oscillator 6 high frequency (Fig.6) consists of a quartz oscillator frequency 1760 kHz, performed on the chip 84 type K155LAZ. Quartz 85 stabilizes the oscillation frequency of 1760 kHz. Resistors 86 88 and capacitor 89 ensure the normal operation of the generator on the f-microcircuit

84. In order to obtain a good duty ratio of the excitation voltage and to obtain an antiphase voltage, the exciter is connected to the output of the quartz oscillator and a frequency divider 90 is connected to A, which is light-duty on two D-triggers of the K155TM2 type microcircuit.

 To the anti-phase outputs of the divider 90 is connected to the inputs of the pre-amplifier 5 power.

The master oscillator 6 is designed to receive two anti-phase voltages of frequency 440 kHz for driving power amplifier 5.

The output circuit 7 is, for example, an upstream output transformer and separation capacitors, which ensure that the output of the power amplifier 5 is matched to the load and that the active 8 and passive 9 electrodes are electrically separated from the circuit of the device.

The power supply to the microcircuits 31 of the modulator 3, 84 and the divider 90 of the generator 6 is carried out from a source of stabilized voltage of +5 V (not shown).

The power supply of the preamplifier 5 power is carried out from a source of unstabilized voltage of +20 V (not shown).

Before working with the device, the resistor 36 and 22 sliders are installed in the lower position according to the scheme

The passive electrode 9 is placed on the patient's body as close as possible to the surgical area. The surface of the passive electrode 9 should fit snugly to the patient's skin.

When the device is switched on, the voltages of +60 V are applied to the inputs of the first and second channels of the modulator 3, and the master oscillator 6 and the modulating pulse pulses of the second channel of the modulator start to work. 3, Antiphase excitation signals with a frequency of 440 kHz from the output of the master oscillator 6 are fed to the amplifiers of power bodies 5. The excitation signal is amplified by a push-pull amplifier at transistors 53-56 and located on the secondary windings of a transformer 57. The amplitude of the excitation voltage at the gates of transistors 75-78 is 20-25, which is enough to saturate these transistors and the terminal power amplifier B in key mode . The power supply of the final stage of the power amplifier is carried out by the modulated current pigment C1 from the cathode of summing diode 4,

To turn on the current at the output of the device, double the switch 52 is pressed. At the same time, from the output voltage regulator of the first channel of the modulator 3 - resistor 22, the voltage is applied to the base of transistor 17 and from its emitter load (resistor 28) to the base of transistor 20, Thus, at the emitter of the transistor 20, t, e, at the output of the 1st, th channel, for example -) |: This corresponds to the voltage taken from the slider of the resistor regulator 22,.

At the same time, pressing the pedal of the switch 52, the voltage from the regulator 36 is supplied to the base of the transistor 34 and from its emitter load to the base of the transistor 35. Thus, on the emitter of the transistor 35, the voltage will correspond to the voltage removed from the slider of the regulator of the resistor 36, From the generator of modulating pulses (from 8 of the microcircuit 31), with a duration of 10 µs, a repetition period of 1000 ISS, is sent to

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the current amplifier on the transistor 32 and from the secondary winding of the transformer 44 to the switching transistor 33. For the duration of the modulating pulse, the transistor 33 enters saturation and the voltage from the emitter of the transistor 35 is applied between the cathode and the anode of the summing diode 4. Thus, the diode 4 for a time the action of the modulating pulse is locked and the power of the power amplifier 5 is powered only by the voltage from the emitter of the transistor 35, t, eo from the output of the second channel; In the pause between the modulation and 1F1 pulses, the transistor 33 is closed, di 4 is opened directly by the applied voltage from the emitter of the transistor 20 tons, e, from the output of the first channel, and power amplifier 5 is powered only from the output of the first channel. la In this case, the form of the supply voltage of the terminal stage of the power amplifier 5 is obtained in general form, shown in Fig. 7, corresponds to the output voltage of the second channel of the modulator 3 and is controlled by a resistor 36 in the range from the voltage value at the output of the first channel to the voltage value the output of the first channel plus 60 V, and ".., respectively, fV t N

The output voltage of the first channel is controlled by the resistor 22 in the range from 0 to 60 V. Thus, the voltage U is projected by amplitude-modulated pulses with a modulation factor depending on the relative position of the resistor motors 36 and 22,

Voltage Uj ,,. modulates the output high-frequency current of the device and at the output the form has the general form shown in FIG. 8,

The amplitude of the output current in radio pulses, which determines the depth of the breakdown of the cell membranes of the tissue, and hence the depth of coagulation, is determined by the resistor 36, which controls the output voltage of the second channel of the modulator 3,.

The amperage of the output current in the pauses between the radio pulses, which determines the average power at the output of the device, is determined by the resistor 22 regulating the output voltage of the first channel of the modulator 3. Since the pulse ratio of the radio pulses is large, their power, with a modulation factor less than 90%, is less than 3 % of

impulses with big with

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the average output power of the device, t „e, the power of the radio pulses can be neglected. Thus, the average output power of the device is controlled only by the resistor 22, and the depth of coagulation and tissue destruction is regulated only by the resistor 36.

The proposed device allows to obtain a modulation factor of the output current within the range of O - 100%. For example, when adjusting the output current only by the resistor 22 (the slider of the resistor 36 is in the lower position), the output average power of the device changes from 0 to the maximum value, and the modulation coefficient is zero. This mode corresponds to the cutting mode used for electrosurgical effects.

When adjusting the output current only by the resistor 36 (the slider of the resistor 22 is in the bottom

position) the modulation factor is adjusted; the amplitude of the input current is 100%. the shape of the current is similar to the shape of the output current of the known device, which corresponds to the coagulation mode. By changing the position of the slider of the resistors 36 and 22, it is possible to change the modulation factor of the output current within O - 100%, thereby making a smooth transition from cutting mode to cutting with hemostasis and coagulation, which is sometimes necessary when performing accurate dosing. electrochemical influences.

Thus, the proposed device makes it possible to independently regulate the modulation coefficient of the output current and the average output power while retaining all the advantages of the known device (high efficiency, good

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thermal regime), which is due to a number of cases

moreover, since both tori have an independent and each of them feeds the yitani source, we can regulate the maximum levels of the voltage amplifier itself and decrease the modulus of the high-frequency current

Coefficient of modulus of high frequency current is the ratio between the amplitude current in the radio frequency of the high frequency between radio pulses. radio modulation impulse modulation large radio impulses of no effect on the average power, so the pulse can be neglected

With the help of one

the sub-frequency current between the radio pulses from the output of the second capacitor and the sum of the second channel is modulated by the modulating current of the device, in addition to the sum of the output voltage of the device.

This, in turn, is about the possibility of both changing the output power level in a large range of the current amplitude in pa and the change in current amplitude in the radio fixed level of the device's power

with n

a change in the power amplifier of a key generator on MOS transistors and a master oscillator with a fixed amplitude of the excitation voltage.

Due to the introduction of a modulator into the power supply circuit of the power amplifier and the implementation of its two-channel with individual power sources of the channels, it is possible to obtain at the output of the modulator a voltage modulated in amplitude periodically following rectangular

pulses with high duty cycle.

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about

5 adjustable amplitude

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moreover, since both channels of the modulator have independent adjustment and each of them is powered from a separate yitani source, the maximum and minimum power supply voltage levels of the power amplifier can be independently controlled and thereby the modulation cycle of the device's output high-frequency current can be changed.

The modulation factor of the output high-frequency current determines the ratio between the amplitude of the high-frequency current in the radio pulse and the amplitude of the high-frequency current in the pauses between the radio pulses. With a high duty cycle of radio pulses and a modulation coefficient of more than 10%, the power of radio pulses does not have a significant effect on the average output power, therefore the power of radio pulses can be neglected

Using one modulator channel

the output high-frequency current of the device in the pauses between the radio pulse and the voltage from the output of the second channel 1 of the controller, adding to the summation diode with the output voltage of the first channel, determines the amplitude of the output current of the device in the radio pulse and the second channel mod the torus is connected to a smart diode only for the duration of the modulating pulse

This in turn makes it possible to both change the average output power level of a device in a large range with a fixed current amplitude in radios, and changes in the current amplitude range in radio pulses at a fixed level of average output power of the device 5, which is practical

using the device, in particular, when using the device for carrying out, high-frequency electrocoagulation of tissues separate regulation

The above parameters determine the possibility of adjusting in a wide range of electrosurgical effects when cutting or coagulating, causing

the most secure coagulation process in various practical situations due to the separate adjustment of the coagulation depth and the average power level, which ensures the processing of the required tissue volume.

During coagulation, the energy of the radio pulses provides only an electrical breakdown of the cell membranes of the tissue to a depth determined by the amplitude of the radio pulses, and homogenization of the tissue structure, and the main heating of the tissue to coagulate it is caused by high-frequency current in the pause between radio pulses.

Claims (1)

Invention Formula An electrosurgical generator containing a high frequency master oscillator, a high frequency power amplifier of a key type on MOS transistors, an output circuit, a modulator, a power supply voltage of about 10 and FIG 2 A power amplifier cascade and electrodes connected to the output of a high frequency power amplifier through an output circuit, characterized in that, in order to reduce injuries by preventing excessively deep tissue destruction during coagulation of large volumes, it is equipped with a two-channel with independent adjustment of the output voltage of each channel and connected to the power supply circuit of the power amplifier, the inputs of the modulator channels are connected to their own voltage source, and the output through summing diode - to the power amplifier, the inputs of which are connected to the excitation oscillator You are a hydami. sh / V 608 IS 3 Sltm ftoroy MML Have sweat D  min - Woo pc with Time Fig Time