RU2263485C2 - Method and device for controlling plasma flux at surgical influence onto body's tissues - Google Patents

Abstract

FIELD: medical equipment.

SUBSTANCE: method is based upon change in plasma generator's electric power at change in voltage supply to input of generator. Voltage is applied to input of generator and is subject to change smoothly and without delays due to applying and storing of electric signals of transient processes power in storage. Signals come from current and voltage detectors through corresponding rectifying-differentiating circuits and AND gate. Transient process energy discharge level is preset by means of introducing smooth changes in storage. Device for controlling plasma flux has high-frequency voltage generator with high-frequency voltage converter which has low-voltage electrode connected with plasma generator. The latter is provided with needle electrode. Device also has AND gate. Low-voltage output is connected with current and voltage inductance detectors which both are connected with input of AND gate through differentiating circuits. Output of AND gate is connected with storage provided with shunting variable resistor.

EFFECT: improved efficiency of operation.

2 cl, 2 dwg

Description

The invention relates to medicine and is intended for use in the surgical treatment of tissues of the human body and animals with a plasma stream.

SUBSTANCE: device comprises a voltage-controlled high-frequency generator connected to a low-voltage winding of a plasma torch, inductive current and voltage transient sensors in a generator-plasma torch circuit, a filtering pulse of transient processes and converting them into a generator control voltage. Technical result: a given level of control voltage of a high-frequency generator sets the balance of the number of transient pulses that occur during an electric discharge at the moment of dissection of the body tissue, i.e. removable electric power when cutting tissue.

The closest in technical essence to the present invention is a device for coagulation of tissues, containing a power source from a high-frequency voltage generator with an adjustable frequency and a high-frequency converter connected to it, the output of which is connected to a plasmatron in the form of a needle electrode (RF patent No. 2100013).

The disadvantages of this device include the inability to adjust the input electric power to the plasma torch, controlled by a change in frequency. In addition, the lack of a smooth inertialess adjustment of the plasma flow power at the time of coagulation and dissection of the tissue, depending on the energy delivered by the coagulator.

The objective of the invention is to develop a method and device for controlling the plasma flow during surgical treatment of body tissues.

As a result of the application of the invention, it becomes possible to use arising transients in the electric circuit in the control circuit and using the “I” coincidence logic — the inertialess control processes of the set or continuously adjustable power of the plasma torch.

The above technical result is achieved by the fact that in the method of controlling the plasma flow during surgical treatment of body tissues, including dissection and coagulation of tissues, the resulting transient processes in the electric network are removed by inductive voltage and current sensors, after conversion they are fed to the input of the coincidence logic circuit “I”, accumulate on containers and then use in the circuit for adjusting the power of the plasma flow on the needle electrode of the plasma torch with the possibility of smooth adjustment for controlling I have a plasma flow, moreover, by changing the voltage on the storage capacitor, the generator operating mode is smoothly changed and, accordingly, the electric power supplied by the plasma torch is applied, and to control the operation mode the voltage from the storage capacitor is supplied to the generator input, and the control voltage level on the storage capacitor is smoothly regulated with a shunt resistance and to the input of the generator supply voltage from the storage capacitance.

To perform smooth inertialess adjustment of the plasma flow power on the needle electrode in the proposed method for controlling the plasma flow during tissue dissection and coagulation, the energy of transient pulses in the coagulator’s electrical circuit is converted by a differential circuit and a matching circuit, stored on capacitors and converted to voltage, which is supplied to the generator input moreover, the control voltage level on the storage capacitance is smoothly regulated by a shunt variable resistance.

To control the operating mode, voltage is supplied to the generator input from the storage tank.

In the proposed method, the voltage at the storage capacitance is changed with the possibility of a smooth inertialess change in the operating mode of the generator and, accordingly, the electric power supplied by the plasmatron.

To implement the method, a device for inertialess control of a plasma flow during surgical treatment of body tissues is proposed, comprising a high-frequency voltage generator with a high-frequency voltage converter, connected to a plasma torch with a needle electrode, in which inductive voltage and current sensors are installed at the low-voltage output of the generator, there is also a converter connected with the input of the logical match circuit “AND” in the circuit for adjusting the power of the plasma flow on a needle the electrode of the plasma torch, and the output of the “I” matching logic circuit is connected to the storage capacitance with the possibility of supplying voltage from it to the generator input.

The technical result is achieved through the use in the feedback loop of the arising pulses of transients in the electrical circuit of the coagulator, fed to the input of the logic circuit “I” for further regulation of the power of the plasma torch.

Transient processes occur in the coagulator’s electric circuit, the power of which depends on the power of the plasma flow during a high-voltage spark discharge dissecting tissues, and a corona discharge during coagulation.

The essence of the invention is illustrated by drawings.

1, conditionally shown on the sinusoids of a high-frequency generator of different capacities arising transient processes in voltage ΔU _{1,2,3, ... n} and current ΔI _{1,2,3, ... n} . The set quantitative level of impulses of emerging transients in the electric circuit of the coagulator is used as a way of controlling the power of the plasma torch during a surgical effect on the body tissue.

Figure 2 presents a General diagram of a device for controlling plasma flow during surgical exposure to body tissues.

The device contains a power source from a controlled high-frequency voltage generator 1 in the range from zero to its maximum power and a high-frequency transformer converter 10 connected to it, the low-voltage output of which is connected to the plasma torch 2, a voltage sensor 3 and a current sensor 4, rectifying-differentiating, are connected to the low-voltage output chains of voltage 5 and current 6, the logic circuit And 7, the storage capacitance 8, shunt variable resistance 9.

The device operates as follows.

During an electric discharge at the moment of dissection of the tissue, transient processes occur in the generator-plasmatron electric circuit. Depending on the discharge power (tissue dissection depth), a quantitative power of transient pulses arises. Transients in the electrical circuit are removed by voltage sensors 3 and current 4 through the rectifier-differentiating circuits 5 and 6 and are fed to the matching circuit And 7 and then to the storage capacitance 8, where they are converted to voltage. Scheme And 7 "catches" at the same time voltage dips and current spikes, i.e. transients in the electrical circuit, while other random changes in voltage and current through the AND circuit are not passed. Transients in the electrical circuit of the coagulator are “captured” by the circuit And both in stand-alone mode and in the network mode of supply of the coagulator. The electrical signals of the transient processes after the AND circuit are accumulated on the capacitance 8, where they are converted to the corresponding voltage level. The discharge time of the tank 8 is set by the shunt resistance 9. By smoothly changing the resistance 9, the necessary charge-discharge balance of the storage tank 8 is established, i.e. the control voltage level of the generator 1 supplying the plasmatron 2. By changing the control voltage level, the operating point shifts during generation, thereby changing the generation amplitude, i.e. by changing the operating mode of the generator, the power given to them changes, respectively, and the removed power from the high-frequency transformer converter 10, and then sequentially from the plasma torch 2.

An example of the proposed method.

In the case of the required level of plasma spark or corona discharge power established during surgical treatment in the area of the treated tissue, the operator, by changing the shunt resistance 9, sets the conditions for the required power of the plasma flow removed from the needle electrode of the plasma torch 2. The energy of the resulting transient processes in the coagulator electric circuit at the time of surgical treatment after differentiating chains 5, 6 through the coincidence circuit And 7 accumulates on the capacitance 8. Resistance 9 sets the discharge time yes capacity 8, i.e. the discharge voltage level of the accumulated transient energy at the capacitor 8. Thus, the charge-discharge mode of the accumulated capacitance 8 from the transient energy arising in the electric circuit is set, converted to a control voltage level supplied to the generator input, which gives the required power a low voltage, then transformed by the plasmatron into a high voltage of a given power on a needle electrode. The electrical energy from the needle electrode is removed in the form of a plasma stream during tissue processing.

In another case, when it becomes necessary to gradually increase or decrease the power at the moment the plasma stream is exposed to the treated tissue, the operator in a similar way from zero to maximum and vice versa gradually changes the plasma stream power on the needle electrode.

The dynamic process of controlling the removed power of the plasma stream is carried out in the inertialess mode of operation of the device, which is very important for surgical treatment of tissues. This method improves the efficiency and quality of the therapeutic effect during coagulation and allows the coagulator to be effectively used as a plasma scalpel.

Claims (2)

1. A method of controlling the plasma flow during surgical exposure of body tissues by changing the electric power of the plasma torch when changing the voltage supply to the generator input, characterized in that the voltage supply to the generator input is changed smoothly and without inertia by supplying and accumulating transient energy electric signals on the storage tank processes coming from current and voltage sensors, through the corresponding rectifier-differentiating chains and the coincidence circuit And, at m smooth variation of the shunt resistance is set the level of transient energy to discharge the storage capacitance. 2. A plasma flow control device for surgical exposure of body tissues, comprising a high-frequency voltage generator with a high-frequency voltage converter, the low-voltage output of which is connected to a plasma torch equipped with a needle electrode, and an I matching circuit, characterized in that additionally inductive sensors are connected to the low-voltage output voltage and current sensor through rectifier-differentiating chains connected to the input of the coincidence logic circuit AND, the output of which connected to the storage tank, provided with a variable resistance shunt.

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