Electrosurgical generator with improved inverter control and method of operation - Patents.com

Abstract

To output a high-frequency AC voltage to an electrosurgical instrument.SOLUTION: An electrosurgical generator includes an inverter that generates a high-frequency AC voltage having variable frequency and amplitude. The high-frequency AC voltage is fed to an output socket for the electrosurgical instrument. The inverter is a multi-level inverter controlled by a reference signal defining the waveform of the generated HF AC voltage. The reference signal is defined by a datagram including a finite series of amplitude and frequency data vectors arranged in prescribed order for a defined number of periods. By such datagrams including descriptive data for a desired HF sinusoidal curve, the data amount and bandwidth required can be reduced. Thereby, a variety of modes can be described using a minimum of data which can be as short as just a few dozen bytes long. This allows efficient control even of complex modes.SELECTED DRAWING: Figure 3a

Description

[Technical Field]

[0001] The present invention relates to an electrosurgical generator configured to output a high frequency alternating voltage to electrosurgical equipment, and a method of operating the same. The electrosurgical generator comprises a control unit and a high voltage inverter, which generates a high frequency alternating voltage of variable frequency and amplitude, which is supplied to an output socket for connection to the electrosurgical equipment. [Background technology]

[0002] Electrosurgical generators typically feature somewhat complex functionality with a large set of functions, allowing them to address a variety of applications. These functions differ in the way they power the electrosurgical equipment. The different ways of powering the electrosurgical equipment are typically referred to as "modes." If simple tissue cutting is to be achieved, the cut mode is selected, providing a moderate voltage continuously to the electrosurgical equipment. If coagulation is more important, a different mode is selected, such as the spray or coagulation mode, which uses a slightly higher voltage with a low duty cycle. Many more different modes exist for other types of applications. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] European Patent Application Publication No. 3248560 Summary of the Invention [Problem to be solved by the invention]

[0004] Currently, electrosurgical generators include high-voltage generators, most of which are formed by resonant converters. This is a highly reliable and proven technology. However, it has the drawback that the frequency is not reliably controllable, and the amplitude can only be adjusted by changing the voltage of the DC power supply of the resonant converter. Any change in frequency and / or amplitude leads to rather awkward handling.

[0005] To improve adjustability, it is known to provide electrosurgical generators with inverters configured as H-bridges (see patent document 1), however, special control methods must be used to avoid excessive harmonic formation.

[0006] Furthermore, the present applicant has developed an electrosurgical generator equipped with a multilevel inverter having a cascaded topology. This significantly improves the adjustability of the output signal. It is possible to rapidly change the amplitude and frequency. Furthermore, in principle, it is possible to change the output voltage curve into a random shape. However, doing so requires a dedicated, high-performance controller, such as an FPGA, capable of driving the inverter current at a frequency much higher than the output frequency of the generated high voltage. A typical driving frequency is 200 MHz, with an output voltage alternating at a frequency of 400 kHz. While this is feasible, providing such a high driving frequency to the reference signal requires a large number of data points in rapid succession, thereby necessitating a costly, high-speed controller.

[0007] It is an object of the present invention to provide an electrosurgical generator and improved inverter control which reduces the above-mentioned drawbacks. [Means for solving the problem]

[0008] The solution according to the invention is characterized in the independent claims. Advantageous embodiments are the subject of the dependent claims.

[0009] In an electrosurgical generator configured to output a high frequency AC voltage to an electrosurgical instrument, the electrosurgical generator comprises a control unit and a high voltage inverter, which generates a high frequency AC voltage of variable frequency and amplitude, which is supplied to an output socket for connection to the electrosurgical instrument. According to the invention, the inverter is a multilevel inverter controlled by a reference signal defining the waveform of the generated high frequency AC voltage, the reference signal being defined by a datagram containing a finite sequence of amplitude and frequency data vectors arranged in a predetermined order for a defined number of periods.

[0010] First, some terminology will be explained.

[0011] A multilevel inverter is an inverter that is capable of producing output voltages at various levels, as opposed to providing only on / off outputs with positive and / or negative polarity. Typical topologies include, but are not limited to, cascaded H-bridge, neutral point clamp, and flying capacitor.

[0012] A datagram is understood to be a data packet of finite length. It typically has a small size of up to 256 bytes, especially 50 bytes or less. It may optionally comprise source and destination identification information, but this is not required.

[0013] The term "period" is used herein to refer to the time it takes to complete one full cycle of a waveform, typically a high frequency AC voltage waveform such as that produced by an inverter.

[0014] Controlling an inverter and providing its reference signal in accordance with the present invention avoids the need for expensive high-speed controllers, such as FPGAs. The present invention provides a different approach to creating the reference signal, specifically, based on a datagram, which provides a flexible and concise description of the reference signal to be generated. To this end, a special data format has been developed that includes a finite sequence of amplitude and frequency data vectors arranged in a predetermined order for a defined number of periods. The datagram describes the reference signal to be generated using minimal information.

[0015] Electrosurgical generators provide their high-frequency AC output voltage in various modes. Simple modes are provided, such as the "PureCut" mode, as a continuous, oscillating voltage. Additionally, there are several more complex modes configured to vary the output voltage over time in terms of frequency, amplitude, duty cycle, and / or crest factor. One example is the "SprayCoag" mode, which has very high voltage in a spike-like manner for a very short time, e.g., one or two oscillations, followed by a much longer pause of very low or no voltage. The duration of the pause is at least one order of magnitude (10 times) longer than the spike, e.g., 20 times longer.

[0016] Providing reference signals for multilevel inverters to be able to generate output voltages according to rather complex modes can be very data intensive. Multilevel inverters that generate high frequency AC output voltages up to 500 kHz are usually driven by much higher frequencies, typically in the range of about 200 MHz. Depending on the number of levels, ½ byte, 1 byte, or even 2 bytes may be required for each data point. This results in rather high bandwidth requirements, which are demanding and costly.

[0017] The present invention realizes that by providing datagrams containing descriptive data for a desired high-frequency sinusoidal curve of the output voltage, rather than a bulk stream of data points, the amount of data, and therefore the required bandwidth, can be significantly reduced. This would be obvious if the desired output voltage were a continuous voltage and the datagrams would require only two digit bits. Surprisingly, however, when datagrams according to the present invention are used, specifically datagrams containing a finite sequence of amplitude and frequency data vectors in a predetermined order for a defined number of periods, more complex modes also require only small amounts of data. Various modes can thereby be described using a minimum amount of data that can be as short as just a few dozen bytes in length. Clearly, this is a significant reduction in bandwidth requirements.

[0018] Preferably, the reference signal is generated by a reference signal generator configured to generate a reference signal defined by a datagram. More preferably, the reference signal generator comprises a receiver configured to receive a data record describing the reference signal. The reduced bandwidth requirements of the datagram according to the present invention thereby allow for increased flexibility in locating the reference signal generator within the electrosurgical generator, without being restricted to proximity to the source of the datagram.

[0019] The present invention preferably enables efficient generation of a reference signal by using a synthesizer. For this purpose, the reference signal generating device preferably comprises a decoder configured to decode the data record received by the receiver and extract a data vector for each period, a sequencer configured to output a signal related to the amplitude and frequency from the extracted data vector for each period in a sequence defined by the data field and to repeat this sequence, and a synthesizer configured to generate, for each data vector, an oscillating wave having an amplitude and frequency according to each data vector, the series of oscillating waves forming a reference signal, which is supplied to an inverter. In connection with being controlled by the datagram according to the present invention, continuous and discontinuous reference signals for the output voltage can be easily generated.

[0020] Preferably, the datagram includes a plurality of data fields, one for each period, each data field including one of a plurality of data vectors having values ​​indicating the amplitude and frequency of each one of the defined number of periods. Providing its own data field including a data vector for each period allows a high degree of flexibility in defining complex sequences, thereby enabling the reference signal forming device to form a reference signal even for complex modes of the electrosurgical generator, such as modes having pulses of voltage separated by pauses.

[0021] Advantageously, the datagram further comprises a first additional data field indicating the polarity, in particular the polarity of the first half-wave of the first period, thereby allowing the selection of whether the reference signal starts with a positive half-wave or a negative half-wave, and thereby allowing the surgeon using the electrosurgical generator to select the polarity (positive or negative first half-wave) of the high voltage output voltage.

[0022] As a further advantage, the datagram further comprises a second additional data field indicating the number of periods, which allows the receiver, and in particular the decoder and sequencer, to check the integrity of the datagram, thereby easily identifying and rejecting one or more incomplete datagrams with missing data vectors over several periods, thereby improving operational security.

[0023] Additionally or alternatively, the datagram may preferably include additional data fields, in particular start and end bytes, indicating start and end information. This clearly identifies the beginning and end of the datagram. This further improves the data quality of the datagram. Using the start and end information, it is also possible to have datagrams spanning an unspecified number of periods, thereby facilitating the inclusion of additional periods with additional data vectors for more complex codes. This improves the possibility of future updates. Optionally, the start and / or end information may further determine the direction of the data flow, thereby reading the datagram data, and / or may include a data integrity data field, for example, a checksum such as a cyclic redundancy checksum (CRC).

[0024] Preferably, the datagram contains data fields for a minimum of two periods. This allows a somewhat freer choice of duty cycle, which is a great advantage for defining complex modes of the electrosurgical generator.

[0025] In a preferred embodiment, the synthesizer is configured to generate half-wave oscillations, and the periods in the datagrams relate to the duration of the half-wave oscillations. This allows for individual frequencies and amplitudes to be assigned to each half-wave. This allows for even greater granularity in defining the voltage curves of the modes. Furthermore, this allows for asymmetric generation of the reference signals, thereby providing additional flexibility in configuring more complex modes. It is worth noting that the data vector concept allows for the frequency and / or amplitude of the second half-wave to be different from the frequency and / or amplitude of the first half-wave. This is an important feature of the present invention, and the ability to have different frequencies for the first and second half-waves is a major advantage. Thus, the half-wave capability provides great flexibility in configuring a wide variety of different reference signals for different modes.

[0026] Furthermore, the synthesizer may be configured to generate only unipolar half-waves, in particular positive half-waves. A synthesizer capable of generating only half-waves can be simplified relative to a bipolar synthesizer. Furthermore, for the same number of bits, a higher quantization and therefore a higher resolution of the voltage amplitude can be achieved, thereby enabling a finer reproduction of the sinusoidal voltage curve. As a further advantage, the amount of unwanted harmonics can be reduced due to better quantization.

[0027] Preferably, the synthesizer is connected to an inverting circuit configured to invert every other half-wave generated by the synthesizer. By inverting every second half-wave, a fully bipolar oscillation can be generated using a simplified half-wave synthesizer.

[0028] Preferably, the inverting circuit is a switchable inverting circuit that is switchable according to a selection signal that indicates whether the even or odd half-waves should be inverted. Thereby, it can be easily determined by the selection signal whether the reference signal, and therefore the oscillations that are generated, start with the positive half-wave and / or the negative half-wave. Preferably, the selection signal of the inverting circuit is automatically set according to a first additional data field indicating polarity.

[0029] In particular, when the electrosurgical generator supplying the output voltage to the electrosurgical instrument operates for a longer period of time or in complex operating modes, such as those involving mode alternation (e.g., alternation between CUT and COAG modes), it may be necessary from time to time to update the data vectors of some (but not all) periods of the reference signal. Clearly, a new complete datagram can be generated and transmitted, which is received and processed by the reference signal generator. However, it is more efficient to transmit only a reduced set (fragment) of the datagram rather than the entire datagram. Advantageously, the receiver is further configured to receive datagram fragments, each of which contains a limited number of data fields with corrected amplitude and frequency data vectors and associated period-related identifiers, said limited number being greater than or equal to one but less than the defined number of periods. This allows the reference signal generator to selectively replace the amplitude and frequency data vectors for one (or several) predetermined periods without requiring the complete transmission of the entire datagram. This further reduces the amount of data transmitted. Furthermore, this allows for faster updates, which are very important for the ability to quickly alternate between operating modes, for example, between CUT and COAG modes.

[0030] To this end, the decoder is preferably configured to extract the data vectors and identifiers, and the sequencer is configured to selectively replace the output signals in terms of amplitude and frequency, over the relevant time period, by those received in the decoded datagram fragment, so that only the data vectors that have actually changed need to be replaced, thereby simplifying and speeding up processing.

[0031] Advantageously, the datagrams are compressed such that the bit length of the amplitude and / or frequency values ​​in the data vector is limited to the number of levels and frequency range of the multilevel inverter, thereby avoiding unnecessary transmission of longer data, which results in more compact datagrams and allows for faster transmission and processing.

[0032] Preferably, the datagrams are less than 256 bytes, and preferably less than 50 bytes.

[0033] In most cases, the receiver is operatively connected to a controller for receiving the datagrams, said controller being local to the electrosurgical generator. However, in advantageous embodiments, it is also possible for the receiver to be configured to receive datagrams from a remote controller. The compact datagrams and resulting reduced bandwidth requirements therefore facilitate operation over remote control connections, particularly wireless connections.

[0034] The present invention further relates to a corresponding method of operating an electrosurgical generator. For further explanation, and in order to avoid unnecessary repetition, reference is made to the above-mentioned description of the electrosurgical generator, which is applicable mutatis mutandis.

[0035] The invention is explained in more detail below with reference to advantageous exemplary embodiments. [Brief explanation of the drawings]

[0036] [Figure 1] FIG. 1 shows a block diagram of a surgical generator with attached electrosurgical equipment according to an exemplary embodiment. [Figure 2] 1 shows a block diagram of a cascaded multilevel inverter. [Figure 3a] 1 shows a schematic diagram of an example datagram. [Figure 3b] 1 shows a schematic diagram of an example datagram. [Figure 4] 1 illustrates a block diagram of a reference signal forming device according to an exemplary embodiment; [Figure 5a] A first embodiment regarding the reference signal is shown. [Figure 5b] A first example of the corresponding datagram data is shown below. [Figure 6a] A second embodiment of the reference signal is shown. [Figure 6b] A second example of the corresponding datagram data is shown below. [Figure 7] FIG. 10 is an exemplary flow diagram of a method for forming a reference signal. DETAILED DESCRIPTION OF THE INVENTION

[0037] An electrosurgical generator according to an exemplary embodiment is shown in the block diagram of Figure 1. The electrosurgical generator, generally identified by the reference number 1, comprises a housing 11, which comprises an output socket 14 for an electrosurgical instrument 16, which is connected to the output socket 14 of the electrosurgical generator 1 via a high-voltage connecting cable. A main connecting cable 12, connectable to the public electricity grid or other suitable power supply means, is provided for supplying power to the electrosurgical generator 1.

[0038] The electrosurgical generator 1 comprises a power supply unit 2 housed in a housing 11 and supplied by a mains connection cable 12 (see FIG. 1 ). The power supply unit 2 includes a rectifier and supplies a DC voltage to a DC link 20, which in turn supplies an inverter. The inverter 3 generates a high-frequency AC voltage in the high-voltage range of several kilovolts. The high-frequency, high-voltage output is supplied to the output socket 14 via an output line 23, a low-pass filter 25, and via an isolation transformer 26 which steps up the high voltage and includes a series capacitor 27 to block any DC current into the output socket 14. An electrosurgical instrument 16 can be connected to the outlet of the output socket 14. The output voltage and current at the output socket 14 are measured by a voltage and current sensor 28, and corresponding measurement signals are supplied to the control device 10 by a feedback circuit 19. This is generally known in the art and will not be described further for the sake of brevity.

[0039] The operation of electrosurgical generator 1 is controlled by controller 10, which is connected to power supply 2 and the inverter by signal lines. Controller 10 operates electrosurgical generator 1 based on functions stored in memory of controller 10. The functions define the operating characteristics and modes of electrosurgical generator 1. The functions are selectable by a user using an input device, which may be a conventional key and button interface and / or a touchscreen interface (not shown). For example, the power to be output may be selected by power selection knob 13, and the mode to be used may be selected by mode selection knob 14.

[0040] The inverter generates a high-frequency AC voltage in the range between 200 kHz and 4 MHz. The inverter is embodied as a multilevel inverter 3. The waveform, frequency, duty cycle, and amplitude of the voltage generated by the multilevel inverter are determined by an inverter control device 31 based on a reference signal generated by a reference signal generating device 30. The reference signal generating device 30 is determined by the control device 10 according to the selected power and mode.

[0041] The multilevel inverter 3 comprises a plurality of cells, which are arranged in a cascade configuration as shown in FIG. 2. There are two different types of cells, which are arranged in two groups, each supplied with a different DC voltage. The first group comprises low-voltage cells 3-1, 3-2, and 3-3, which are supplied with a lower DC voltage, 12 V in the illustrated embodiment. The second group comprises high-voltage cells 3-4 and 3-5, which are supplied with a higher DC voltage, 48 V in the illustrated embodiment. Both groups are connected in series, so that the voltages output by each of the cells 3-1 to 3-5 are added together to form a common output voltage Vout. The illustrated configuration can provide output voltages ranging between −132 V and +132 V, which is equivalent to 23 levels with 12 V steps.

[0042] 3a and 3b show examples of datagrams. In the first example of a datagram shown in FIG. 3a, datagram 100 includes data fields 101 and 102 for two periods. Each data field 101 and 102 includes a data vector 121, 122, each of which has two values: one value "A" indicating the amplitude and another value "f" indicating the frequency of each period. These values ​​thus describe the characteristics of each period in terms of amplitude and frequency. Furthermore, datagram 100 includes a first additional data field 111 indicating the polarity of the first period, i.e., whether the oscillation starts with a positive wave or a negative wave. Furthermore, datagram 100 includes a second additional data field 112 indicating the number "n" of periods containing data vectors in data fields 101 and 102. In this example, "n" is 2. Optionally, datagram 100 may include additional data fields 113 and 114 for start and end bytes.

[0043] For datagrams containing up to 15 duration-related data fields, the available data fields are shown in Table 1 below.

[0044] [Table 1]

[0045] Table rows in italics indicate additional data fields. Other rows contain data vectors containing amplitude and frequency values ​​for each of up to 15 periods. The amplitude values ​​are relative, not absolute.

[0046] 3b shows a more complex datagram 200. It contains four separate data fields 201, 202, 203, and 204 for two periods and for each half-wave of either period. Each contains one of the data vectors 221, 222, 223, and 224, so that for the same period, its positive half-wave may have a different amplitude and / or frequency than its negative half-wave. Furthermore, like datagram 100, datagram 200 also contains an additional data field 211 for the polarity and an additional data field 212 for the number of periods. The value in additional data field 211 indicates the polarity of the first half-wave of each period. Additionally, datagram 200 may optionally include additional data fields 213, 214 for start and end bytes.

[0047] The data fields of datagram 200, with separate data fields for each half-wave, are shown in Table 2 below.

[0048] [Table 2]

[0049] As with Table 1, the italicized rows of Table 2 indicate additional data fields. Other rows contain data vectors containing amplitude and frequency values ​​for any half-wave of each of up to 15 periods. The amplitude values ​​are relative, not absolute. It is worth noting that these datagrams 200 allow the frequency for the second half-wave to be different from the frequency of the first half-wave. This is an important feature of the present invention, providing great flexibility in configuring a wide variety of different reference signals for different modes.

[0050] 4 shows a block diagram of an exemplary embodiment of a reference signal forming device 30 that receives these datagrams 100 and 200 to form a reference signal for the inverter 3. It comprises a receiver 4 connected to the control device 10. It is configured to receive datagrams 100, 200 describing the reference signal to be formed from the control device 10 local to the electrosurgical generator 1.

[0051] Optionally, such datagrams 100, 200 may be transmitted from a remote device 92, preferably over a secure wireless connection 99, thereby enabling remote control of the reference signal forming device 30. The low bandwidth requirements of the datagrams 100, 200 are advantageous for remote controls which typically have limited bandwidth.

[0052] The receiver 4 transmits the received datagrams 100, 200 to a decoder 5. The decoder 5 is configured to decode the datagrams and extract the data vectors 121, 122, 221, 222, 223, 224 from the various data fields, and further extract data from additional data fields 111, 112, 113, 114, 211, 212, 213, 214. The decoder 5 supplies the extracted data to a sequencer 6. The sequencer 6 is configured to arrange the data extracted from the data vectors for each period into the appropriate sequence as defined by the data fields, and once the end of the sequence is reached, to start over and repeat the sequence again and again. This is done until a new datagram containing new data is received, or until a data fragment containing updates to some of the data vectors is received, and then these updated data vectors replace each previous one without interrupting the sequence. The data for amplitude "A" and frequency "f" extracted from the data vector are fed to Digital Control Synthesizer 7, which generates a continuous oscillation containing a sequence of waves, amplitudes, and frequencies for each wave in the sequence, as determined by the data extracted from the data vector of the datagram. Note that in the embodiment shown in Figure 4, Digital Control Synthesizer 7 is optionally configured to provide only a unipolar stream, in this case positive half waves. This allows for twice the resolution using the same number of bits.

[0053] To achieve the omission of the negative half-wave, a switchable inversion circuit 8 is provided. It is configured to invert every other half-wave, thereby forming the omitted negative half-wave. A polarity signal extracted from the additional data fields 111, 211 is applied to control the inversion circuit 8. If the extracted polarity data requests a positive polarity, the first half-wave and all subsequent odd half-waves are not inverted, and inversion is performed on the second half-wave and all subsequent even half-waves, thereby generating a full wave with a positive first half-wave. Conversely, if the extracted polarity data requests a negative polarity, inversion is performed on the first half-wave and all subsequent odd half-waves, thereby generating a full wave with a negative first half-wave. This completes the formation of the full-wave reference signal 38, which is output from the reference signal generator 30 and supplied to the inverter controller 31 for processing by the multilevel inverter 3.

[0054] FIG. 5a shows an example of a reference signal formed in this manner by the reference signal forming device 30. The reference signal is an uncomplicated signal. In this example, it is a sine wave suitable for the "pure cut" mode of the electrosurgical generator 1. FIG. 5b shows the data values ​​and parameters used for the various data fields of the datagram. Additionally, the bit length for each of the data fields is shown. The total amount of data required to control the multilevel inverter 3 by defining the reference signal with a datagram is just 37 bits. This datagram needs to be sent only once, and the reference signal forming device 30 generates a continuous reference signal having the waveform, amplitude, and frequency defined by the datagram. This contrasts sharply with the large amount of data required to control the multilevel inverter 3 using conventional techniques.

[0055] FIG. 6a shows an example of a more complex reference signal. This reference signal is more complex and includes two periods defining half waves. Therefore, it uses a datagram like datagram 200 shown in FIG. 3b. The frequency of the first period is somewhat high (350 Hz), while the frequency of the second period is much lower (19 Hz). The large amplitude of the first period and the low, or even zero, amplitude of the second period, together create a needle-like reference signal with a duty cycle of approximately 5.5%, which is well suited for the "spray and coagulation mode" of the electrosurgical generator 1. As this example shows, even a complex reference signal with a large duty cycle can be created using minimal data—just 69 bits in this example. Again, this contrasts sharply with the large amount of data required to control a multilevel inverter 3 using conventional techniques.

[0056] FIG. 7 shows an exemplary flow diagram of a method for forming a reference signal for controlling the multilevel inverter 3. Upon receiving the datagram 100 in step 81, a reference signal is formed in step 83, as detailed above. In many cases, the reference signal defined by the datagram 100 is directly used (via branch “n”) to control the inverter 3 in step 89 and define the waveform, frequency, and amplitude of the high-frequency AC voltage generated by the multilevel inverter 3. However, if the check for receipt of a data fragment in step 85 reveals that such a data fragment has been received, the flow of operations branches (via branch “p”) to perform extraction of a data vector contained in the data field contained in the data fragment in step 86. The retrieved data vector then replaces the corresponding original data vector, and an updated reference signal is formed in step 88. Finally, in step 89, the multilevel inverter 3 is controlled based on the reference signal, including any updates due to the data fragment, if applicable, thereby generating a high-frequency AC voltage having the waveform, frequency, and amplitude defined by the datagram 100 used to form the reference signal. [1] According to a first aspect of the present invention, An electrosurgical generator configured to output a high frequency alternating current voltage to an electrosurgical instrument (16), comprising: The electrosurgical generator comprises a control device (10) and a high voltage inverter (3), which generates a high frequency AC voltage having a variable frequency and amplitude, and which is supplied to an output socket (14) for connection to an electrosurgical instrument (16); The inverter is a multilevel inverter (3) controlled by a reference signal that defines the waveform of the generated high-frequency AC voltage; The reference signal is defined by a datagram (100, 200) containing a finite sequence of amplitude and frequency data vectors arranged in a predetermined order for a defined number of periods. [2] According to the second aspect of the present invention, in the first aspect, The reference signal is provided by a reference signal generator (30). [3] According to a third aspect of the present invention, in the second aspect, The reference signal forming device (30) - a receiver (4) configured to receive a data record containing said datagram (100, 200); - a decoder (5) configured to decode the data records received by said receiver (4) and extract said data vectors for each of said time periods; - a sequencer (6) configured to output amplitude and frequency signals from the extracted data vector for each period in a sequence defined by a data field, and to repeat this sequence; - a synthesizer (7) configured to generate, for each data vector, an oscillatory wave having an amplitude and frequency in accordance with said respective data vector; A series of oscillating waves forms the reference signal, which is fed to the inverter (3). [4] According to a fourth aspect of the present invention, in one of the first to third aspects, The datagram (100, 200) includes multiple data fields (101, 102; 201, 202, 203, 204), There is one data field for each period, Each data field contains one of a plurality of data vectors having values ​​indicative of the amplitude and frequency of each one of the defined number of periods. [5] According to a fifth aspect of the present invention, in one of the first to fourth aspects, Said datagram (100, 200) further comprises a first additional data field (111, 211) indicating the polarity, in particular the polarity of the first half-wave of the first period. [6] According to a sixth aspect of the present invention, in one of the first to fifth aspects, Said datagram (100,200) further includes a second additional data field (112,113) indicating the number of said periods. [7] According to a seventh aspect of the present invention, in one of the first to sixth aspects, The datagram (100, 200) includes additional data fields (113, 114; 213, 214) that indicate start and end information, specifically the start and end bytes. [8] According to an eighth aspect of the present invention, in one of the third to seventh aspects, The synthesizer (7) is configured to generate half-wave oscillations. The period in the datagram (100,200) relates to the duration of the half-wave oscillation. [9] According to a ninth aspect of the present invention, in the eighth aspect, The synthesizer (7) is configured to generate only unipolar half waves, in particular positive half waves.

[10] According to a tenth aspect of the present invention, in the ninth aspect, An inverting circuit (8) is connected to the synthesizer (7), and is configured to invert every other half-wave generated by the synthesizer (7).

[11] According to an eleventh aspect of the present invention, in the tenth aspect, The inverting circuit (8) is a switchable inverting circuit that is switchable according to a selection signal that indicates whether the even half-waves or the odd half-waves should be inverted.

[12] According to a twelfth aspect of the present invention, in the eleventh aspect, The selection signal is automatically set according to a first additional data field (111, 211) indicating the polarity.

[13] According to a thirteenth aspect of the present invention, in one of the third to twelfth aspects, The receiver (4) is further configured to receive datagram fragments; The datagram fragment contains a limited number of data fields (101, 102; 201, 202, 203, 204) containing corrected amplitude and frequency data vectors and associated time period identifiers; The limited number is one or more, but less than the defined number of periods.

[14] According to a fourteenth aspect of the present invention, in the thirteenth aspect, the decoder is configured to extract the data vector and the identifier; The sequencer is configured to selectively replace the amplitude and frequency of the output signal over the associated time period with that received in the decoded datagram fragment.

[15] According to a fifteenth aspect of the present invention, in one of the first to fourteenth aspects, The datagram (100, 200) is compressed such that the bit length of the amplitude and / or frequency values ​​in the data vector is limited to the number of levels and frequency range of the multilevel inverter.

[16] According to a sixteenth aspect of the present invention, in one of the third to fifteenth aspects, The receiver (4) is connected to a control device (10) for receiving the datagrams (100, 200) and / or is configured to receive the datagrams (100, 200) from a remote control device (92).

[17] According to a seventeenth aspect of the present invention, 1. A method of operating an electrosurgical generator configured to output a high frequency alternating current voltage to an electrosurgical instrument (16), comprising: The electrosurgical generator comprises a control device (10) and a high-voltage inverter (3), the inverter (3) generating a high-frequency AC voltage having a variable frequency and amplitude, the high-frequency AC voltage being supplied to an output socket (14) for connection to an electrosurgical instrument (16), the inverter being a multi-level inverter (3); The method includes forming (83) a reference signal according to the datagram (100, 200); said datagram (100, 200) defines said reference signal, said reference signal comprising a finite sequence of amplitude and frequency data vectors arranged in a predetermined order for a defined number of periods; The method includes controlling the multilevel inverter (3) by the reference signal that defines the waveform of the generated high frequency AC voltage.

[18] According to an eighteenth aspect of the present invention, in the seventeenth aspect, The reference signal is further formed according to one of the second to sixteenth.

Claims

1. An electrosurgical generator configured to output a high frequency alternating current voltage to an electrosurgical instrument (16), comprising: The electrosurgical generator comprises a control device (10) and a high voltage inverter (3), which generates a high frequency AC voltage with variable frequency and amplitude, which is supplied to an output socket (14) for connection to an electrosurgical instrument (16); The inverter is a multilevel inverter (3) controlled by a reference signal that defines the waveform of the generated high-frequency AC voltage; the reference signal is defined by a datagram (100, 200) comprising a finite sequence of data vectors arranged in a predetermined order for a defined number of periods, the data vectors having values ​​related to amplitude and frequency, Electrosurgical generator.

2. The reference signal is provided by a reference signal forming device (30).

2. An electrosurgical generator according to claim 1.

3. The reference signal forming device (30) a receiver (4) adapted to receive a data record containing said datagram (100, 200); a decoder (5) adapted to decode the data records received by said receiver (4) and to extract said data vectors for each of said periods; a sequencer (6) adapted to output signals relating to amplitude and frequency from said extracted data vector for each period in a sequence defined by a data field, and to repeat this sequence; a synthesizer (7) configured to generate, for each of the data vectors, an oscillatory wave having an amplitude and a frequency according to said respective data vector; A series of oscillating waves forms the reference signal, which is fed to the inverter (3); The datagram (100, 200) includes a plurality of data fields (101, 102; 201, 202, 203, 204), There is one data field for each period, each data field including one of a plurality of data vectors having values ​​indicating the amplitude and frequency of each one of the defined number of periods; 3. An electrosurgical generator according to claim 2.

4. The datagram (100, 200) further includes a first additional data field (111, 211) indicating polarity.

4. An electrosurgical generator according to claim 3.

5. said datagram (100, 200) further comprising a second additional data field (112, 113) indicating the number of said periods; 4. An electrosurgical generator according to claim 3.

6. The datagrams (100, 200) contain additional data fields (113, 114; 213, 214) indicating start and end information.

4. An electrosurgical generator according to claim 3.

7. The synthesizer (7) is configured to generate half-wave oscillations. The period in the datagram (100, 200) relates to the duration of the half-wave oscillation.

4. An electrosurgical generator according to claim 3.

8. The synthesizer (7) is configured to generate only unipolar half waves.

8. An electrosurgical generator according to claim 7.

9. an inverting circuit (8) connected to the synthesizer (7), the inverting circuit (8) configured to invert every other half-wave generated by the synthesizer (7); 9. An electrosurgical generator according to claim 8.

10. the inversion circuit (8) is a switchable inversion circuit, switchable according to a selection signal indicating whether the even half-waves or the odd half-waves should be inverted; 10. An electrosurgical generator according to claim 9.

11. the selection signal is automatically set according to a first additional data field (111, 211) indicating polarity; 11. An electrosurgical generator according to claim 10.

12. The receiver (4) is further configured to receive datagram fragments; The datagram fragment contains a limited number of data fields (101, 102; 201, 202, 203, 204) containing corrected amplitude and frequency data vectors and associated time period identifiers; The limited number is one or more, but less than the defined number of periods; 4. An electrosurgical generator according to claim 3.

13. the decoder is configured to extract the data vector and the identifier; the sequencer is configured to selectively replace the amplitude and frequency output signals over the associated time periods with those received in the decoded datagram fragments; 13. An electrosurgical generator according to claim 12.

14. The datagram (100, 200) is compressed such that the bit length of the amplitude and / or frequency values ​​in the data vector is limited to the number of levels and frequency range of the multilevel inverter.

2. An electrosurgical generator according to claim 1.

15. The receiver (4) is connected to a control device (10) for receiving the datagrams (100, 200) and / or is configured to receive the datagrams (100, 200) from a remote control device (92).

4. An electrosurgical generator according to claim 3.

16. 1. A method of operating an electrosurgical generator configured to output a high frequency alternating current voltage to an electrosurgical instrument (16), comprising: The electrosurgical generator comprises a control device (10) and a high-voltage inverter (3), the inverter (3) generating a high-frequency AC voltage having a variable frequency and amplitude, the high-frequency AC voltage being supplied to an output socket (14) for connection to an electrosurgical instrument (16), the inverter being a multi-level inverter (3); The method includes forming (83) a reference signal according to the datagram (100, 200); the datagram (100, 200) defining the reference signal comprises a finite sequence of data vectors arranged in a predetermined order for a defined number of periods, the data vectors having values ​​related to amplitude and frequency; The method includes controlling the multilevel inverter (3) by the reference signal that defines the waveform of the generated high frequency AC voltage. method.

17. forming the reference signal receiving a data record containing said datagram (100, 200); decoding the received data records to extract the data vectors for each of the time periods; outputting amplitude and frequency signals from said extracted data vector for each period in a sequence defined by a data field, and repeating this sequence; for each of the data vectors, forming an oscillatory wave having an amplitude and frequency in accordance with said respective data vector; A series of oscillating waves forms the reference signal, which is fed to the inverter (3); The datagram (100, 200) includes a plurality of data fields (101, 102; 201, 202, 203, 204), There is one data field for each period, each data field including one of a plurality of data vectors having values ​​indicating the amplitude and frequency of each one of the defined number of periods; 17. The method of claim 16.

18. A method of operating the electrosurgical generator, comprising operating an electrosurgical generator according to any one of claims 4 to 15.

17. The method of claim 16.

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