DE3502193A1 - ELECTROSURGICAL DEVICE - Google Patents

Description

Elektrochi rurgi see caution

The invention relates to an electrosurgical device for use in surgical diathermy.

Surgical diathermy is a procedure that uses heat to cut tissue and coagulate blood. This heat is developed by the passage of high-frequency electric current, which in the case of the monopolar Electrosurgery passes through the patient's body from the location of cutting or coagulation. This High frequency current, which is typically the order of magnitude from about 500 kHz to about 1 MHz with a power output of several hundred watts is provided by an electrosurgical device. The achieved surgical Effect, i.e. either cutting or coagulation, is determined by the waveform of the output current used.

In monopolar electrosurgery, electrosurgical Device connected to an "active" and a "plate" electrode. The active electrode has a very

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small surface area and is used for cutting and / or used to coagulate blood. The plate electrode, which is usually tied to the patient's thigh, has a much larger surface area and allows the active current to be passed to the electrosurgery Device flow back.

Given the high levels used in electrosurgery Performance levels can cause severe burns to the patient suffer when the plate electrode is not in good electrical contact with the skin or when the electrical Connection between this electrode and the electrosurgical device is poor or interrupted.

It is therefore extremely important that those of these The circuit formed by the two electrodes, and in particular the plate electrode, is constantly and reliably monitored and that the electrosurgical device is provided with suitable safety switches which act on this monitoring speak to.

Circuits that monitor the connection between the plate electrode and the electrosurgical device, are known and widely used, as are circuits that facilitate patient contact and monitor the plate electrode. To this end, such circuits generally monitor the flow of current and / or the voltage on the plate electrode.

In addition, the electrosurgical device itself should be as fail-safe as possible and automatic shutdowns provide if electrical / electronic failure appear. For this purpose the device must be self-monitoring.

In the prior art, these have been seen in electrosurgery Control and monitoring functions available to the devices by electrical or electronic Provided circuits that tubes, relays, transistors, and monolithic integrated circuits into Use connection with discrete components. The resulting devices are complex and expensive Manufacture and cannot easily be adapted to the increasing requirements in terms of security and flexibility.

In addition, the electrical gift is the current one available electrosurgical devices are limited in shape and height. The waveforms of the Operating voltages were determined based on crude and subjective observations of this limited range of possible waveforms selected. It is believed, however, that the optimal size and shape composition is not can only vary from operation to operation, but also during an individual cutting or coagulation process. Thus, there is a desire for an apparatus which is capable of generating a wide variety of output waveforms for the investigation and subsequent selection of improved surgical diathermy techniques.

The invention is based on the object sine electrosurgical To create device that is inexpensive to manufacture and more flexible security monitoring and Control functions and the delivery of a difference of outputs enabled.

To solve this problem, the invention proposes an electrosurgical one Apparatus for use in surgical diathermy which, according to the invention, comprises a micro-computer

for controlling the output of the device, the micro-computer for receiving one or more signals from an operator interface to select a desired one Output from the electrosurgical device and of a device for sample formation at one or more points of the electrical state of the electrosurgical Device and for outputting one or more control signals to a power generator circuit for Generating the power output of the electrosurgery Device and to one or more devices for ** delivery to see information about the state of el ektroc.i rurgi Device is connected to the user.

In a preferred embodiment, it is electrosurgical Device designed and arranged to have both monopolar and bipolar outputs depending on Selection generated by the user.

In a performance where the electrosurgical Device has a monopolar output, a safety circuit for monitoring a plate electrode circuit be provided, the micro-computer being connected to this circuit and by signals from this Circuit is addressable.

The safety circuit preferably monitors the connection between a plate electrode and the electrosurgical one Device, the voltage on the plate electrode with respect to earth and the electrical contact between them Electrode and the patient's body.

The waveform of the output of the electrosurgical device is preferably generated by the micro-computer.

The micro-computer can be connected to an external computer, for example via a telephone line. This enables the external computer to be in the micro-computer takes over stored operating data and also changes the program of the micro-computer. That kind of one Operating data obtained from a large number of electrosurgical devices can in this way be collated centrally and analyzed to obtain data relating to the optimal output of the electrosurgical device among different Conditions to maintain These data can then be updated when the program is changed and dated to the latest Prior to the operation of these same electrosurgical devices can be used.

In a preferred embodiment of the invention the micro-computer is directly programmable by the user, which makes it possible to use the device available Tailor the outputs provided to the user and / or the surgical procedure being used. The modification or rewrite the micro-computer program preferably achieved by replacing a preprogrammed plug-in storage device.

In another embodiment, the micro-computer programmed so that the electro-surgical device a test routine of a self-diagnostic circuit when switched on and / or when it is requested to do so by actuating a manually operated switch. This option offers considerable advantages in terms of overall security and error detection.

Further features, details and advantages of the invention emerge from the claims and the following description preferred embodiments and based on the drawing.

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AO show:

1 shows a block diagram of the operation of an embodiment of an electrosurgical device according to the invention Contraption;

Figure 2 is a block diagram of a preferred embodiment of the invention;

3 is a block diagram of an embodiment of a monopoiaren Lei stungssi "^ uerungs- and amplifier circuit; and

Figure 4 is a block diagram of an embodiment of a bipolar power amplifier circuit.

In Fig. 1, the electrosurgical unit includes one Micro-computer 1, the instruction signals A from a User interface, from through security monitoring circuits generated signals B and signals C is addressable to be seen by other parts of the electrosurgical Device and indicate the condition of these parts. The micro-computer processes the received signals and generates control signals D for controlling the type, shape and level of the output power of the electrochemical device and for switching this output power on and off, as well as signals E for controlling visual displays and audible ones Devices that provide information on the state of the electrosurgical Make the device available to the user.

Fig. 2 shows an electrosurgical device used for Delivery of both a monopolar and a bipolar output waveform formed at a respective output is. Unlike the monopolar modes of cutting

and coagulation uses bipolar electrosurgery not a plate electrode with a large area. In this Case, the diathermy flow between two peaks becomes one Scissors formed. This is used for the coagulation of blood vessels and has its special application in difficult Procedures that require localized and precisely controlled coagulation, e.g. neurosurgery, plastic Surgery and 1aparoscopic sterilization. Bipolar Electrosurgery only requires low power outputs in the range of 50 watts compared wit the 400 watts that generally used in monopolar electrosurgery and therefore, unlike monopolar electrosurgery, does not in itself pose a major potential hazard for the patient.

In this embodiment, the micro-computer 1 includes a pulse pattern generator 2 in addition to those devices which usually constitute a micro-computer, namely one Mikro-Prozesso ", program and data memory, address decoder, a clock generator, BUS driver, a monitoring time device and other peripheral devices. The program memory contains the program instructions and data for the overall operation of the microprocessor, while the data memory for the temporary storage of data regarding the status various parts of the electrosurgical device is available. In the illustrated embodiment the micro-computer is from the NSC 800 family of microchips educated.

The pulse pattern generator 2 is a clock whose output from the microprocessor in accordance with pre-set waveforms for monopolar and bipolar operation is determined, which are stored in the program memory. The output of this generator 2 determines the

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gi? η outputs of the device obtained waveform as it will be described in detail later. In this embodiment, the generator 2 is formed by counter-clock generator chips.

The micro-computer 1 is programmed to be 1-bit broad binary input signals from ten two-position switches 3a to 3j receives via suitable interface devices for the selection of operating modes, for example Schmitt trigger, Potential divider and low-pass filter. Of these are three Finger switch provided for selecting one of the three basic operating modes, namely cutting, coagulation and bipolar. Three electric foot switches each duplicate the action of these finger switches, and one more Pneumatically operated foot switch creates an additional facility for selecting the bipolar mode of operation.

Three more two-position switches are on the electrosurgical Device provided. A lock switch 3j allows the three bipolar select switches to be locked 3c, 3d and 3g, so that a surgeon can use any or all of these switches during a single operation can use. The switch 3h enables the selection of the monopolar operation without the indication of "cutting" or "coagulation", and the switch 3i e enables switching from monopolar to bipolar operation or vice versa.

The micro-computer 1 also receives 1-bit wide binary signals from two other switches 4a and 4b that are on the electrosurgical device to select certain Secondary modes of operation are provided. Switch 4a is a two-position switch that can be used to select one of two voltage levels, high and low, which is used for bipolar operation. Switch 4b is on the device

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and has four positions for the selection of one of four preprogrammed waveforms contained in the program memory. Again, these are binary signals the micro-computer 1 via suitable interface devices fed.

The micro-computer 1 is also addressable by an 8-bit wide binary coded signal from three digital power level control switches 5a to 5c, respectively for the pre-selection of the The level of benefit provided for each of the three main operating modes is.

As mentioned above, the output waveform of the electrosurgical device is controlled by means of the pulse pattern generator 2. At the suggestion of the microprocessor, this generator delivers two 1-bit wide signals to two Lines 19, one of which has two power amplifiers 7m and 7b and the others only with the power amplifier 7m is connected to control the pulse pattern of the output current waveform.

Monopolar or bipolar output selection is achieved with the aid of a signal received from the microprocessor one of two "inhibit" lines 8m and 8b sent which are connected to a monopolar power control device 10 or the bipolar amplifier 7b. This Signal prevents the power supply of the output which is not selected by the user.

To generate a monopolar output, the microcomputer 1 supplies an 8-bit wide signal via a digital / analog converter 9 for setting the output voltage of the High-performance control device 10, which the monopolar amplifier

ker 7m supplied. This control device 10 provides a supply with a continuously variable power a set voltage available that depends on the Voltage level signal is determined, which is provided by the micro-computer available. With the present Embodiment, the voltage can be any value between Accept 0 and 150 volts.

The control device 10 is formed by a switching regulator, which are known per se, and contains in this embodiment, see FIG Inductance Ll loads. A diode D2 keeps the current flowing the inductance Ll upright during the periods when the transistor FETl is not conductive. A voltage feedback circuit made up of a power control amplifier 22 and associated components, including a switching controller 25, ensures that the output voltage the control circuit 10 follows the input of the power control amplifier 22. This input is derived from the microprocessor via the analog / digital converter 9. The entire switching regulator is fed by a conventional DC voltage power supply 21.

The voltage ^{output of the control circuit '1} D is fed directly to the monopolar power amplifier 7m. As can be seen in Fig. 3, this circuit includes two high power MOSFET switches FET2 and FET3 which are arranged to operate in push-pull and which are connected to one end of each of the two parallel primary windings of an output transformer T _M , the other Ends are connected to the output of the power control device 10. The pulse pattern derived from the micro-computer is linked to the gates of the MOSFET switches FET2 and FET3 by suitable high-gain buffer circuits, which generate a pulse

generator circuit 24 known type form to a fast Ensure switching with a rise time of less than 100 nano-seconds. In the cutting mode delivers this generator circuit generates pulses of constant width and constant spacing in response to a signal from the pulse pattern generator 2, while this circuit generates a waveform in the connection and coagulation modes which has a pulse group pattern generated by the generator 2. This combination of tension and Pulse pattern control allows any desired pulse pattern to be generated at any voltage level up to about 3 kV peak to peak at the secondary winding of the transformer L ·.

To the power generator circuit 24 against overloads and to protect too high current, the voltage across each transistor FET2 and FET3 is measured during the conductive period. This voltage becomes one through diodes D5 and D6 Current limit trigger circuit 23 transmitted. When the voltage at the input of the circuit 23 has a predetermined Value is exceeded, a signal is sent to the pulse generator to thereby cause the pulse spacing to approach hundreds of times its normal value enlarge. This ensures that no excessively high currents flow through the transistors FET2 and FET3.

The bipolar amplifier 7b is connected to a fixed voltage rail, and the voltage level selection between "high" and "low" is achieved with the aid of a 1-bit wide signal that is sent by the microprocessor via the line 11 connected to the bipolar amplifier 7b is supplied. The fine control of the output power level of the bipolar amplifier 7b is achieved with the help of a pulse group modulation as provided by the micro-computer via the output of the pulse pattern generator 2 in response

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on setting the bipolar power level control switch 5c.

As shown in Fig. 4, the bipolar power amplifier 7b includes two MOSFET switches FET4 and FET5 of medium power which operate in push-pull and are connected to one end of each of the two parallel primary windings of an output transformer Tp. The pulse pattern derived from the micro-computer is linked to the gates of the MOSFET switches FET4 and FET5 with the aid of suitable high-gain buffer circuits which form a pulse group generator 20 in order to ensure fast switching with a rise time of less than 100 nano-seconds. The high / low voltage level is applied to the other ends of the primary windings of the transformer T _ß . This combination of pulse pattern control and high / low voltage level allows any desired pulse pattern to be generated at either 400 V peak to peak (high power) or 200 V peak to peak (low power) on the secondary winding of the transformer T _R , where the variation of the pulse pattern controls the total output power.

The output of the amplifiers 7m and 7b is applied to the corresponding output of the unit via the respective transformer T _M , T _ß and insulating capacitors C and C.

A safety circuit 12 is provided which monitors the plate electrode when the electrosurgical device is used in the monopolar mode. In the case a failure in the connection between the platen and the electrosurgical device becomes 1-bit wide Binary signal sent to the micro-computer 1, which in turn sends out signals to prevent an output from the monopolar amplifier 7m, and actuates the alarm signals.

does. During the surgical operation, the Safety circuit the voltage on the plate electrode to earth, compares this to a voltage reference level and sends if this value is a safety range exceeds, a 1-bit wide signal to the micro-computer, which switches off the amplifier 7m and / or switches on alarm signals. The safety circuit also monitors isolating the patient by measuring the impedance between the plate circuit and ground. If the established Impedance indicates the possibility of a too large line through the patient to earth, wit J again a 1-bit signal sent to the micro-computer to prevent line surrender and turn on alarms.

Operating states of the electrosurgical device itself are also monitored. A 1-bit signal that is one to Indicates high output voltage at the output of the power control unit 10 is fed to the micro-computer 1 via a power detection line 13, and the microprocessor causes the power output accordingly is switched off and the alarm signals are activated.

The programming of the computer ensures that an "unsafe" or "illegal" combination of selected Parameter is fed to the rest of the device and that an alarm condition is appropriately indicated.

In the present embodiment, the booster circuits 7m and 7b are inherently against an overcurrent protected, and this eliminates the need for a thermostat to maintain the temperature reached by these amplifiers supervised.

The electrosurgical device is various provide audible and visible indications with corresponding

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The corresponding outputs of the micro-computer are connected in order to transmit information to the user about the state of the device and to provide alarm signals. In the device shown in FIG. 2, the microcomputer 1 supplies a 1-bit output signal via respective current buffers for switching on one of three optical display devices 14a to 14c to display which of the three basic operating modes is active. Nine light emitting diodes 15a to 15h indicate which has been selected to the available SE ¹ jndären modes as well as other "Statuainformationen, broad in response to a respective 1-bit signal from the micro-computer.

The power output setting selected by means of the power level switches 5a to 5c is controlled by the micro-computer is read and displayed by one of three bar display devices 16a to 16c, respectively. Each tick mark is through an 8-bit signal is operated from the micro-computer 1 via a respective digital / analog converter 17a to 17c.

The micro-computer is also programmed to display those operating to the user via the optical display devices to communicate parameters that are available prior to selection. Accordingly, at any point in time during startup of the devices, one or more of a set of causes optical displays 14a to c, 15a to 15h and 16a to 16c to flash to indicate those available choices and therefore direct the user to one appropriate combination.

In the event of an error or alarm condition, the micro-computer will send a 1-bit signal at the same time as an audible signal and optical display device 18 via a current buffer and via both "inhibit" lines 8m, 8b for switching off the Supply of the monopolar and bipolar output.

In a further embodiment, if a fault odor If an alarm condition occurs, the Mi la o-Computer 1 also sends an 8-bit signal to the optical alarm code display device, the type of error or alarm condition detected to display.

In yet another embodiment of the present Invention is the 8-bit binary signal that indicates the type of alarm or error condition that has occurred from the Micro-computer 1 supplied to an integrated circuit for speech synthesis to the appropriate information audibly available to the user.

As an alternative to the line display devices 16b-c, the device can use a seven-segment digital display for displaying the selected level of benefits.

In another embodiment, the micro-computer programmed so that the device performs a self-diagnostic test routine at power-up and / or when it is made to do so by operating a manual switch. In this routine, for example all optical and acoustic display devices 14a-c; 15a - h; 16a-c and 18 in a previously specified sequence is activated, and a failure of any of the components or subsystems of the device sending information to the User supply can be identified before the electrosurgical device is used.

In yet another embodiment, the voltage between the active electrode and the plate electrode periodically monitored by the micro-computer along with the output current, and the output current from the device

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actual performance is calculated and compared with that of the User selected output power compared. if a discrepancy between these values occurs which exceeds a predetermined limit, the micro-computer activates alarm signals and / or switches the power output away.

In another embodiment, the micro-computer passes the ausgedrür by the quotient peak voltage / voltage ^RMS: th crest factor of the appearing at the active electrode voltage and current values and regulates this to ensure a high crest factor, and therefore an optimal coagulation.

In another embodiment, the microprocessor monitors the resistance on the active electrode during a Cutting or coagulation process and controls the output current to ensure that it is completely at an optimum value.

Since both the shape and the level of the output voltage of the electrosurgical device can be controlled directly by the microcomputer, an infinite number of such combinations can be achieved in practice. These Flexibility means that the device is particularly suitable for use as a research tool in the refinement of diathermy surgical techniques.

Furthermore, the device according to the present invention can be used in connection with additional devices for sensing the physiological state of the patient and / or the tissue at the point of diathermy can be used, with the output of these devices directly via an input

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entities of the micro-computer is kept where it is collected and is saved with the corresponding operating conditions for subsequent analysis. The micro-computer can also use these incoming physiological data as an indication of undesired physiological effects monitor so that, if necessary, appropriate signals can be sent out by the microprocessor to indicate the power output switch off and / or activate alarm signals.

As already explained, the overall operation of the micro-computer, and therefore the output of the device, is controlled by the program determined in the program memory consisting of, for example, a ROM, PROM, EPROM or similar device can. Therefore, by simply replacing the relevant integrated circuits, the operation of the electrosurgery can be seen Device to be adapted to the individual case. Furthermore, in a preferred embodiment, the device designed in such a way that der.Benutzer the operating program can change even by replacing a preprogrammed storage device. This enables any user to access the Adapt the output of an electrosurgical device to a specific selection of output waveforms and power levels according to his preference and / or the surgical procedure to be performed to deliver.

In another embodiment, the micro-computer with the help of a BUS with an external computer for data acquisition and connectable for changing the program of the electrosurgical device by this computer.

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Claims (13)

EXPECTATIONS surgical diathermy, characterized by a Micro-computer to control the output of the device, the a) for receiving one or more r signals (A-C) from a user interface for selecting a desired one Output from the electrosurgical device and means for checking the electrical condition of the electrosurgical device one or more places and b) for outputting one or more control signals (E, D) to a power generator circuit for generating the Output power of the electrosurgical device and to one or more devices for providing information on the state of the electrosurgical vision Device is connected to the user. A 21 881/2 - 2 - 2. Device according to claim 1, characterized in that that the waveform pattern of the output of the device generated by the micro-computer. 3. Apparatus according to claim 1 or 2, characterized in that the waveform pattern is generated with the aid of counter-clock chips. 4. Device according to one of claims 1 to 3, characterized in that ^c ie has a monopolar output and the Lei stui.gsgeneratorschal device a power control device (10), the output voltage of which is determined by the micro-computer (1), and a power amplification circuit for supplying the monopolar output with a selected output, and wherein the output voltage of the power control device (10) and a waveform pattern of the micro-computer are applied to the power amplification circuit. 5. Device according to one of the preceding claims, characterized in that it has a monopolar output and a safety circuit for monitoring a having a plate electrode circuit connected to the monopolar output and having a micro-computer connected output. 6. Device according to one of the preceding claims, characterized in that it has a bipolar output and the power generator circuit comprises a power amplification circuit for outputting power to the bipolar output, and wherein a voltage and a waveform pattern determined by the micro-computer are applied to the power amplification circuit respective entrances are made available. 7. Device according to one of the preceding claims, characterized in that it has a bipolar output and the control of the power supplied to this bipolar output by means of pulse group modulation is reached. 8. Device according to one of the preceding claims, characterized in that it is used to deliver power to the monopolar or bipolar output as desired is formed, whereby ° i the monopolar and bipolar output power in each case one of two mutually isolated circuits is generated. 9. The device according to claim 8, characterized by means for preventing the output of power to the monopolar output during a bipolar output and to the bipolar output during a monopolar | polar power output. * 10. The device according to claim 9, characterized in that that when a faulty or alarm condition is displayed by one or more signals received from the micro-computer, the preventing means of the micro-computer for preventing the output of power at least can be operated on the monopolar output. 11. Device according to one of the preceding claims, characterized in that the micro-computer is reprogrammable. 12. Device according to one of claims 1 to 10, characterized characterized in that the micro-computer has a program memory in the form of a plug-in preprogrammed Has device that can be replaced by the user is. 13. Device according to one of the preceding claims, characterized in that the micro-computer is used to carry out programmed into a self-diagnostic test routine is.