Independent control of dual rf monopolar electrosurgery with shared return electrode

Abstract

This application relates to independent control of dual RF monopolar electrosurgery with shared return electrode. More specifically, an electrosurgical generator is disclosed that includes a first radio frequency source having a first power supply configured to output a first direct current waveform, a first radio frequency inverter coupled to the first power supply and configured to generate a first radio frequency waveform from the first direct current waveform, and a first controller configured to control the first radio frequency inverter. The electrosurgical generator also includes a second radio frequency source having a second power supply configured to output a second direct current waveform, a second radio frequency inverter coupled to the second power supply and configured to generate a second radio frequency waveform concurrently with the generation of the first radio frequency waveform, and a second controller configured to control the second radio frequency inverter.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit and priority of U.S. Provisional Patent Applications Nos. 63 / 028,007, 63 / 028,012, 63 / 028,009, and 63 / 028,049, each of which was filed on May 21, 2020. The entire contents of each of the foregoing applications are incorporated herein by reference. Technical Field

[0003] This disclosure relates to systems and methods for controlling an electrosurgical generator. In particular, this disclosure relates to controlling multiple monopolar electrosurgical devices that share a common return path via one or more return electrodes. Background Technology

[0004] Electrosurgery involves applying high-frequency radiofrequency current to the surgical site to cut, ablate, dry, or coagulate tissue. In monopolar electrosurgery, a power source or active electrode delivers radiofrequency alternating current from an electrosurgical generator to the target tissue. The patient returns the electrode away from the active electrode so that the current is conducted back to the generator.

[0005] In bipolar electrosurgery, the return electrode and the active electrode are placed close to each other, creating a circuit between the two electrodes (e.g., in the case of electrosurgical forceps). In this way, the applied current is confined to the body tissue located between the electrodes. Therefore, bipolar electrosurgery typically involves the use of instruments to achieve concentrated delivery of electrosurgical energy between the two electrodes.

[0006] Current solutions for dual-site surgery, which involve using two electrosurgical instruments simultaneously, typically two electrosurgical generators, are cumbersome and costly. Therefore, it is necessary to use a common return path for independent control of multiple ports of a single electrosurgical generator. Summary of the Invention

[0007] This disclosure provides an electrosurgical system comprising an electrosurgical generator having two radio frequency (RF) channels generated by two separate RF sources. Each of the sources includes a power supply configured to output DC power and an RF power inverter configured to output an RF waveform. Individual RF waveforms are supplied to corresponding monopole instruments, and each RF waveform returns via a common return path, which may include one or more return electrode pads. Each of the sources is controlled by its own controller, each controller being coupled to a common clock source. The electrosurgical generator performs broadband measurements of discontinuous or continuous signals from each RF source while simultaneously detecting cross-conduction and crosstalk between the sources. As used herein, cross-conduction is the current flowing through the contact impedance of the relative channels in an energy channel, and crosstalk is radiated interference between energy channels within the electrosurgical generator.

[0008] According to one embodiment of this disclosure, an electrosurgical generator is disclosed. The electrosurgical generator includes a first radio frequency (RF) source having: a first power supply configured to output a first DC waveform; a first RF inverter connected to the first power supply and configured to generate a first RF waveform from the first DC waveform; and a first controller configured to control the first RF inverter. The electrosurgical generator further includes a second RF source having: a second power supply configured to output a second DC waveform; a second RF inverter connected to the second power supply and configured to generate the second RF waveform simultaneously with the first RF waveform; and a second controller configured to control the second RF inverter.

[0009] According to one aspect of the above embodiments, the electrosurgical generator further includes: a clock source coupled to a first controller and a second controller, and configured to synchronize the operation (including sensor sampling) of the first controller and the second controller. A first radio frequency waveform has a first frequency, and a second radio frequency waveform has a second frequency different from the first frequency. The first controller and the second controller are configured to perform frequency domain analysis on the first radio frequency waveform and the second radio frequency waveform, respectively. Each of the first controller and the second controller is further configured to detect cross-conduction between the first radio frequency source and the second radio frequency source based on the frequency domain analysis. Each of the first controller and the second controller is further configured to shut down both the first radio frequency source and the second radio frequency source in response to the detection of cross-conduction.

[0010] According to another aspect of the above embodiments, the first radio frequency (RF) source further includes: a first active terminal connected to a first RF inverter and further configured to be connected to a first electrosurgical instrument. The second RF source further includes: a second active terminal connected to a second RF inverter and further configured to be connected to a second electrosurgical instrument. The electrosurgical generator further includes: a common return terminal configured to be connected to at least one return electrode pad, the common return terminal being connected to the first RF inverter and the second RF inverter. The first RF source further includes: a first isolation transformer having a primary winding connected to the first RF inverter and a secondary winding connected to the first active terminal and the common return terminal. The second RF source further includes: a second isolation transformer having a primary winding connected to the second RF inverter and a secondary winding connected to the second active terminal and the common return terminal.

[0011] According to another embodiment, an electrosurgical system is disclosed. The electrosurgical system includes: a first electrosurgical instrument; a second electrosurgical instrument; and an electrosurgical generator comprising a first radio frequency (RF) source, the first RF source having: a first power supply configured to output a first DC waveform; a first RF inverter connected to the first power supply and the first electrosurgical instrument, the first RF inverter being configured to supply the first RF waveform from the first DC waveform to the first electrosurgical instrument; and a first controller configured to control the first RF inverter. The electrosurgical generator further includes a second RF source having: a second power supply configured to output a second DC waveform; a second RF inverter connected to the second power supply and the second electrosurgical instrument, the second RF inverter being configured to generate a second RF waveform from the second DC waveform to the second electrosurgical instrument while generating the first RF waveform; and a second controller configured to control the second RF inverter.

[0012] According to one aspect of the above embodiments, the electrosurgical generator further includes: a clock source coupled to a first controller and a second controller, and configured to synchronize the operation (including sensor sampling) of the first controller and the second controller. A first radio frequency waveform has a first frequency, and a second radio frequency waveform has a second frequency different from the first frequency. The first controller and the second controller are configured to perform frequency domain analysis on the first radio frequency waveform and the second radio frequency waveform, respectively. Each of the first controller and the second controller is further configured to detect cross-conduction between the first radio frequency source and the second radio frequency source based on the frequency domain analysis. Each of the first controller and the second controller is further configured to shut down both the first radio frequency source and the second radio frequency source in response to the detection of cross-conduction.

[0013] According to another aspect of the above embodiments, the first radio frequency (RF) source further includes: a first active terminal connected to a first RF inverter and further configured to be connected to a first electrosurgical instrument; and the second RF source further includes: a second active terminal connected to a second RF inverter and further configured to be connected to a second electrosurgical instrument. The electrosurgical system further includes at least one return electrode pad, and the electrosurgical generator further includes a common return terminal connected to the at least one return electrode pad and connected to the first RF inverter and the second RF inverter. The first RF source further includes: a first isolation transformer having a primary winding connected to the first RF inverter and a secondary winding connected to the first active terminal and the common return terminal. The second RF source further includes: a second isolation transformer having a primary winding connected to the second RF inverter and a secondary winding connected to the second active terminal and the common return terminal. Attached Figure Description

[0014] In taking into consideration the following detailed description, this disclosure may be understood by referring to the accompanying drawings, in which:

[0015] Figure 1 This is a perspective view of an electrosurgical system according to an embodiment of the present disclosure;

[0016] Figure 2 According to an embodiment of the present disclosure Figure 1 A front view of a dual-RF source electrosurgical generator;

[0017] Figure 3 According to an embodiment of the present disclosure Figure 1 A schematic diagram of an electrosurgical generator;

[0018] Figure 4 It is a link to this disclosure Figure 1 A schematic diagram of the clock source of the first controller of the first RF source and the second controller of the second control source of the electrosurgical generator;

[0019] Figure 5 It is based on this disclosure Figure 1 Frequency response plot of continuous RF waveforms generated by an electrosurgical generator;

[0020] Figure 6 It is based on this disclosure Figure 1 Frequency response plot of discontinuous RF waveforms generated by an electrosurgical generator; and

[0021] Figure 7 This is an embodiment of the present disclosure for operation Figure 1 A flowchart of the method for using an electrosurgical generator. Detailed Implementation

[0022] Embodiments of the electrosurgical system disclosed in this invention are described in detail with reference to the accompanying drawings, in which the same reference numerals denote the same or corresponding elements in each of the several views. As used herein, the term "distal" refers to the portion of the surgical instrument connected thereto that is closer to the patient, while the term "proximal" refers to the portion that is further away from the patient.

[0023] The term "application" can include computer programs designed to perform functions, tasks, or activities to benefit a user. An application can refer to software, for example, as a standalone program or running locally or remotely in a web browser, or other software that a person skilled in the art would understand as an application. Applications can run on a controller or on a user device, including, for example, on a mobile device, an IoT device, a server system, or any programmable logic device.

[0024] In the following description, well-known functions or constructions are not described in detail to avoid obscuring this disclosure with unnecessary detail. Those skilled in the art will understand that this disclosure can be adapted for use with endoscopic instruments, laparoscopic instruments, or open instruments. It should also be understood that different electrical and mechanical connections, as well as other considerations, may be applied to each particular type of instrument.

[0025] The electrosurgical generator according to this disclosure can be used in monopolar and / or bipolar electrosurgical procedures, including, for example, cutting, coagulation, ablation, and vascular sealing procedures. The generator may include multiple outputs for interface connection with various ultrasound and electrosurgical instruments (e.g., ultrasound dissectors and hemostats, monopolar instruments, return electrode pads, bipolar electrosurgical forceps, foot switches, etc.). Furthermore, the generator may include electronic circuitry configured to generate radiofrequency energy, which is particularly suitable for powering ultrasound instruments and electrosurgical devices operating in various electrosurgical modes (e.g., cutting, mixing, coagulation, hemostatic segmentation, electrocautery, jetting, etc.) and procedures (e.g., monopolar, bipolar, vascular sealing).

[0026] refer to Figure 1An electrosurgical system 10 is shown, comprising one or more monopolar electrosurgical instruments 20' and 20'", said monopolar electrosurgical instruments having one or more active electrodes 23' and 23" for treating a patient's tissue (e.g., electrosurgical cutting probes, ablation electrodes, etc.). System 10 may include multiple return electrode pads 26, which are positioned on the patient during use to minimize the chance of tissue damage by maximizing the overall contact area with the patient. Electrosurgical alternating current (RF current) is supplied to instruments 20' and 20' via supply lines 24' and 24'" through a generator 100. Generator 100 is a dual-source RF generator configured to supply separate RF waveforms from individual RF sources to each of instruments 20' and 20" respectively. Alternating current RF current returns to generator 100 via return line 28 and return electrode pad 26. Furthermore, generator 100 and return electrode pad 26 can be configured to monitor contact between the generator and the patient to ensure adequate contact exists between them. In embodiments, system 10 may also include one or more bipolar electrosurgical instruments, such as bipolar electrosurgical forceps (not shown), having one or more electrodes for treating patient tissue. In further embodiments, generator 100 according to this disclosure may also be configured to simultaneously activate bipolar electrosurgical instruments in the manner described below.

[0027] refer to Figure 2 The front 102 of the generator 100 is shown. The generator 100 may include multiple ports 110, 112, 114, 116 to accommodate various types of electrosurgical instruments, and includes port 118 for connection to the return electrode pad 26. The generator 100 includes a display 120 for providing the user with various output information (e.g., intensity settings, treatment completion indicators, etc.). The display 120 is a touchscreen configured to display corresponding menus for instruments (e.g., more monopolar electrosurgical instruments 20' and 20"; electrosurgical forceps, etc.). The user can then adjust the input simply by touching the corresponding menu option. The generator 100 also includes suitable input controls 122 (e.g., buttons, activators, switches, touchscreens, etc.) for controlling the generator 100.

[0028] Generator 100 is configured to operate in various modes and to output a unipolar waveform based on a selected mode. In embodiments, generator 100 may operate in modes including, but not limited to, cutting, mixing, hemostatic segmentation, electrocautery, and spraying. Each of these modes operates based on a pre-programmed power profile indicating how much power generator 100 outputs over a range of varying impedance of the load (e.g., tissue). Each of the power profiles includes power, voltage, and current control ranges defined by a user-selected intensity setting and a measured minimum load impedance.

[0029] The first and second RF waveforms can be continuous or discontinuous, and can have a carrier frequency of about 200 kHz to about 500 kHz. As used herein, a continuous waveform is a waveform with a 100% duty cycle. In embodiments, the continuous waveform is used to apply a cutting effect to tissue. Conversely, a discontinuous waveform is a waveform with a non-continuous duty cycle (e.g., less than 100%). In embodiments, the discontinuous waveform is used to provide a coagulation effect to tissue.

[0030] In cut mode, generator 100 can supply a continuous sinusoidal waveform at a predetermined carrier frequency (e.g., 472 kHz) with a crest factor of about 1.5, wherein the impedance is from about 100 Ω to about 2,000 Ω. The cut mode power profile can include three regions: constant current becomes low impedance, constant power becomes medium impedance, and constant voltage becomes high impedance. In mixed mode, generator can supply a pulse train of the sinusoidal waveform at a predetermined frequency, wherein the pulse train occurs again at a first predetermined rate (e.g., about 26.21 kHz). In one embodiment, the duty cycle of the pulse train can be about 50%. The crest factor of one cycle of the sinusoidal waveform can be about 1.5. The crest factor of the pulse train can be about 2.7.

[0031] The hemostasis and segmentation mode may include a pulse train of a sinusoidal waveform at a predetermined frequency (e.g., 472 kHz) that occurs again at a second predetermined rate (e.g., about 28.3 kHz). The duty cycle of the pulse train may be about 25%. Within an impedance range of about 100 Ω to about 2,000 Ω, the crest factor of one pulse train may be about 4.3. The electrocautery mode may include a pulse train of a sinusoidal waveform at a predetermined frequency (e.g., 472 kHz) that occurs again at a third predetermined rate (e.g., about 30.66 kHz). Within an impedance range of about 100 Ω to about 2,000 Ω, the duty cycle of the pulse train may be about 6.5%, and the crest factor of one pulse train period may be about 5.55. The jetting mode may include a pulse train of a sinusoidal waveform at a predetermined frequency (e.g., 472 kHz) that occurs again at a fourth predetermined rate (e.g., about 21.7 kHz). Within an impedance range of approximately 100Ω to approximately 2,000Ω, the duty cycle of the pulse train can be approximately 4.6%, and the crest factor of one pulse train cycle can be approximately 6.6.

[0032] refer to Figure 3Generator 100 includes a dual-source RF architecture, wherein each RF source is supplied by an individual and separate RF inverter, each of which is powered by an individual and separate DC power supply. More specifically, generator 100 includes a first RF source 202 and a second RF source 302. Each of sources 202 and 302 includes a first controller 204 and a second controller 304, a first power supply 206 and a second power supply 306, and a first RF inverter 208 and a second RF inverter 308. Power supplies 206 and 306 may be high-voltage DC power supplies connected to a common AC source (e.g., line voltage) and supply high-voltage DC power to their respective RF inverters 208 and 308, which then convert the DC power into first and second RF waveforms through their respective active terminals 210 and 310. Energy is returned to them via a shared return terminal 312. Specifically, the electrosurgical energy used to power the monopolar electrosurgical instruments 20' and 20” connected to ports 110 and 112 is delivered through active terminals 210 and 310 and returned through return electrode pad 26 connected to port 118, which is then connected to return terminal 312.

[0033] Active terminal 210 and return terminal 312 are connected to RF inverter 208 via isolation transformer 214. Isolation transformer 214 includes a primary winding 214a connected to RF inverter 208 and a secondary winding 214b connected to active terminal 210 and return terminal 312. Similarly, active terminal 310 and return terminal 312 are connected to RF inverter 308 via isolation transformer 314. Isolation transformer 314 includes a primary winding 314a connected to RF inverter 308 and a secondary winding 314b connected to active terminal 310 and return terminal 312.

[0034] RF inverters 208 and 308 are configured to operate in multiple modes during which generator 100 outputs corresponding waveforms with specific duty cycles, peak voltages, crest factors, etc. It is anticipated that in other embodiments, generator 100 may be based on other suitable power supply topologies. As shown, RF inverters 208 and 308 may be resonant RF amplifiers or non-resonant RF amplifiers. As used herein, a non-resonant RF amplifier refers to an amplifier lacking any tuning components (i.e., conductors, capacitors, etc.) arranged between the RF inverter and the load (e.g., an organization).

[0035] Controllers 204 and 304 may include a processor (not shown) operatively connected to a memory (not shown) that may comprise one or more of volatile, non-volatile, magnetic, optical, or electrical media, such as read-only memory (ROM), random access memory (RAM), electrically erasable programmable ROM (EEPROM), non-volatile RAM (NVRAM), or flash memory. The processor may be any suitable processor (e.g., control circuitry) adapted to perform the operations, calculations, and / or instruction sets described herein, including but not limited to hardware processors, field-programmable gate arrays (FPGAs), digital signal processors (DSPs), central processing units (CPUs), microprocessors, and combinations thereof. Those skilled in the art will appreciate that a processor may be substituted with any logical processor (e.g., control circuitry) adapted to perform the calculations and / or instruction sets described herein.

[0036] Each of controllers 204 and 304 is operatively connected to a corresponding power supply 206 and 306 and / or RF inverters 208 and 308, thereby allowing the processor to control the outputs of the first RF source 202 and the second RF source 302 of generator 100 according to open-loop and / or closed-loop control schemes. The closed-loop control scheme is a feedback control loop in which multiple sensors measure various tissue and energy characteristics (e.g., tissue impedance, tissue temperature, output power, current, and / or voltage, etc.) and provide feedback to each of controllers 204 and 304. Controllers 204 and 304 then control their respective power supplies 206 and 306 and / or RF inverters 208 and 308, which adjust the DC and / or RF waveforms, respectively.

[0037] The generator 100 according to this disclosure may also include a plurality of sensors 216 and 316, each of which monitors the output of the first RF source 202 and the second RF source 302 of the generator 100. Sensors 216 and 316 can be any suitable voltage, current, power, and impedance sensors. Figure 3 In the illustrated embodiment, sensor 216 is connected to leads 220a and 220b of RF inverter 208. Leads 220a and 220b connect RF inverter 208 to the primary winding 214a of transformer 214. Sensor 316 is connected to leads 320a and 320b of RF inverter 308. Leads 320a and 320b connect RF inverter 308 to the primary winding 314a of transformer 314. Therefore, sensors 216 and 316 are configured to sense the voltage, current, and other electrical characteristics of the energy supplied to active terminals 210 and 310 and return terminal 312.

[0038] In another embodiment, sensors 216 and 316 may be coupled to power supplies 206 and 306 and may be configured to sense the characteristics of the DC current supplied to RF inverters 208 and 308. Controllers 204 and 304 also receive input signals from the display 120 and the input controls 122 and / or devices 20' and 20" of the generator 100. Controllers 204 and 304 adjust the power output by the generator 100 and / or perform other control functions thereon in response to the input signals.

[0039] RF inverters 208 and 308 respectively include multiple switching elements 228a-228d and 328a-328d arranged in an H-bridge topology. In embodiments, RF inverters 208 and 308 can be configured according to any suitable topology, including but not limited to half-bridge, full-bridge, push-pull, and similar structures. Suitable switching elements include voltage control devices such as transistors, field-effect transistors (FETs), and combinations thereof. In embodiments, the FETs can be formed of gallium nitride, aluminum nitride, boron nitride, silicon carbide, or any other suitable wide-bandgap material.

[0040] Controllers 204 and 304 communicate with corresponding RF inverters 208 and 308, and more specifically, with switching elements 228a-228d and 328a-328d. Controllers 204 and 304 are configured to output control signals to switching elements 228a-228d and 328a-328d, which may be pulse-width modulation (“PWM”) signals. Specifically, controller 204 is configured to modulate control signal d1 supplied to switching elements 228a-228d of RF inverter 208, and controller 304 is configured to modulate control signal d2 supplied to switching elements 328a-328d of RF inverter 308. Control signals d1 and d2 provide PWM signals that operate RF inverters 208 and 308 at their respective selected carrier frequencies. Additionally, controllers 204 and 304 are configured to calculate the power characteristics of the outputs of the first RF source 202 and the second RF source 302 of the generator 100, and to control the outputs of the first RF source 202 and the second RF source 302 based at least in part on the measured power characteristics, which include, but are not limited to, the voltage, current and power at the outputs of the RF inverters 208 and 308.

[0041] refer to Figure 3 and Figure 4Each of controllers 204 and 304 is connected to a clock source 340, which acts as a common frequency source for each of controllers 204 and 304, enabling synchronization of controllers 204 and 304. Clock source 340 is an electronic oscillator circuit that generates a clock signal to synchronize the operation of controllers 204 and 304. Specifically, the sampling operations of controllers 204 and 304 are synchronized. Each of controllers 204 and 304 generates an RF waveform based on the clock signal from clock source 340 and the selected mode. Therefore, once the user selects one of the electrosurgical modes, each of controllers 204 and 304 outputs first and second control signals to control the corresponding RF inverters 208 and 308 to output first and second RF waveforms corresponding to the selected mode. The selected mode and corresponding RF waveform for each of the first RF source 202 and the second RF source 302 can be the same or different.

[0042] The RF waveforms have different carrier frequencies, such that a first RF waveform has a first carrier frequency and a second RF waveform has a second carrier frequency. Two different carrier frequencies are selected so that controllers 204 and 304 can identify or separate measurement data in the frequency domain. Measurement data is collected by sensors 216 and 316 that monitor the outputs of the first RF source 202 and the second RF source 302. Controllers 204 and 304 use any suitable bandpass technique or any technique that transforms the measurement data to the frequency domain (e.g., Discrete Fourier Transform (DFT) and Fast Fourier Transform (FFT)) to analyze their respective first and second RF waveforms. In an embodiment, controllers 204 and 304 may use an array of Goertzel filters directed to the carrier frequency and harmonics of the RF waveform of a continuous waveform (e.g., those used during cut-out modes). For discontinuous waveforms, the Goertzel filters are directed to the repetition rate and harmonics of the repetition frequency of the waveform being analyzed. Filtering of the measurement data can be performed by an application executable by controllers 204 and 304 (e.g., software instructions).

[0043] The frequencies of the first and second RF waveforms are selected to provide sufficient channel spacing between the carrier frequencies of the first and second RF waveforms, as determined by the bandpass Goertzel filter. (Reference) Figure 5 The frequency response plot is 350°, and the frequency of the continuous waveform relative to the RF port frequency is selected to be at the zero point of the frequency response. This maximizes source-to-source separation.

[0044] refer to Figure 6This diagram illustrates the frequency response plot 360 of a discontinuous waveform, with individual Goertzel filters pointed to the fundamental repetition rate and odd / even harmonics of the analyzed RF waveform. Because the fundamental frequencies are not perfectly orthogonal, some harmonics overlap. This overlap of harmonic groups creates discontinuities in the Goertzel array plot. This is used to detect whether significant cross-conduction from one RF source occurs in sensors 216 or 316 of another RF source. If it is desired to isolate a source containing only one combination of multiple harmonics, the unaffected harmonics are combined with a proportion of the affected harmonics. The isolated cross-conduction information is used as a dose monitor to detect excessive cross-conduction.

[0045] In embodiments where both the first and second RF waveforms are discontinuous, a limited frequency space may be constrained. Discontinuous waveforms can have repetition rates and associated harmonics ranging from approximately 20 kHz to approximately 490 kHz. The repetition rate is the fundamental frequency divided by an integer value. From a signal processing perspective, repetition rates do not allow for perfectly orthogonal solutions. The technique used to determine the power values ​​of each of the first RF source 202 and the second RF source 302 to be used for independent control depends on the level of cross-conduction. Cross-conduction causes real power to be deposited at the contact impedance. Therefore, the controlled power is based on the sum of the cross-conduction power deposited at the contact impedance and the port source power deposited at the contact impedance. In embodiments, the power deposited at the non-contact tissue impedance and the return electrode pad 26 may also be included in the overall calibration of a particular RF port. If frequency identification is used for power control, instruments 20' and 20" and the return electrode pad 26 are used in the calibration procedure prior to the use of generator 100, taking into account cable compensation for both supply lines 24' and 24" and the return line 28, as well as harmonic overlap and cross-conduction. Cross-conduction can also be monitored as a means of mitigating potential dose errors.

[0046] In an embodiment, where one of the first and second RF waveforms is continuous and the other is discontinuous, the continuous RF waveform can be at a higher Goertzel frequency of approximately 481 kHz, while the discontinuous RF waveform can be at a lower frequency of approximately 433 kHz, resulting in virtually no interference between the sources. This is because the frequency response of Goertzel is divisible by 45 (see [link to Goertzel frequency response]). Figure 5 and 6 ) and the concentration of discontinuous energy is at or below its carrier frequency of 433KHz.

[0047] In the embodiment, when the first and second RF waveforms are continuous, since continuous waveforms are typically not perfect sine waves, the preselected unique carrier frequencies of 433 kHz and 481 kHz also conform to the coherent sampling rules used in combination with Goertzel filters to separate continuous RF sources, providing attenuation of constructive or destructive interference signals from the other source. The bandpass filter provides a signal passband region and a lower / upper signal suppression region. The suppression level is variable and depends on the type of bandpass filter designed. Finite impulse response (FIR) filters provide an amplitude-frequency response relationship of the type of sine function (sin x / x). Computationally efficient Goertzel filters are implemented in a manner similar to sampling functions, such as... Figure 5 and 6 The plots shown are 350 and 360.

[0048] refer to Figure 7 A method for controlling a generator 100 is disclosed. The method provides simultaneous dual activation of a first RF source 202 and a second RF source 302. Initially, each of the first RF source 202 and the second RF source 302 is configured by selecting a desired operating mode. As described above, each mode is associated with a predetermined RF waveform, which may be continuous or discontinuous, and is based on a desired tissue effect. Each of the RF sources 202 and 302 may operate in the same or different modes. During operation, when the first and second RF waveforms are supplied simultaneously, instruments 20' and 20" and the return electrode pad 26 contact the tissue, while sensors 216 and 316 measure the characteristics of the first and second RF waveforms. A monopole carrier frequency and coagulation repetition rate can be selected to provide coherent sampling at a time-critical power calculation update rate.

[0049] Sensors 216 and 316, coupled with corresponding controllers 204 and 304, perform broadband measurements of each of the first and second RF waveforms while detecting cross-conduction between the first RF source 202 and the second RF source 302. Additionally, during operation, controllers 204 and 304 provide overcurrent protection during dual activation by monitoring the total current flowing through the return electrode pad 26. Controllers 204 and 304 transmit the instantaneous current value (IT) to the input electrode pad 26 during any suitable time period. 2 The overcurrent value is calculated by averaging the moving average, over a period of approximately 15 to 60 seconds. The moving average can be calculated per second or at any other suitable repetition rate. The overcurrent value is then compared to an overcurrent threshold, which can be approximately 30A. 2 Furthermore, if the threshold is exceeded within any 60-second window monitored at a set rate (e.g., once per second), both RF source 202 and second RF source 302 are turned off.

[0050] Each of controllers 204 and 304 also utilizes signal processing techniques, namely the Goertzel array plotting described above, to identify the simultaneously activated first RF source 202 and second RF source 302. Controllers 204 and 304 are also configured to use the signal processing identification techniques to determine the cross-conduction level (if present) between the first RF source 202 and the second RF source 302. After determining the cross-conduction level, it is used as a safety mitigator, i.e., as a dose error monitor, during simultaneous unipolar RF operation. Specifically, upon detection of cross-conduction by either controller 204 or 304, each of controllers 204 and 304 is configured to output and warn and / or shut down both the first RF source 202 and the second RF source 302 in response to a cross-conduction dose error.

[0051] While several embodiments of this disclosure have been shown in the accompanying drawings and / or described herein, it is not intended to limit this disclosure to these embodiments, but rather to make it as broad as permitted in the art, and this specification should be read in the same manner. Therefore, the foregoing description should not be construed as restrictive, but merely as illustrative of particular embodiments. Those skilled in the art will contemplate other modifications within the scope of the appended claims.

Claims

1. An electrosurgical generator, comprising: The first radio frequency source includes: A first power supply, which is configured to output a first DC waveform; A first radio frequency inverter, connected to the first power supply, and configured to generate a first radio frequency waveform from the first DC waveform, wherein the first radio frequency waveform has a first carrier frequency; and A first controller, configured to control the first radio frequency inverter; and The second radio frequency source includes: A second power supply is configured to output a second DC waveform; A second radio frequency inverter, connected to the second power supply, is configured to generate a second radio frequency waveform simultaneously with the first radio frequency waveform, wherein the second radio frequency waveform has a second carrier frequency different from the first carrier frequency; and The second controller is configured to control the second radio frequency inverter. It further includes: A clock source, which is connected to the first controller and the second controller, and is configured to synchronize the operation of the first controller and the second controller; The first controller and the second controller are configured to perform frequency domain analysis on the first radio frequency waveform and the second radio frequency waveform, respectively, and each of the first controller and the second controller is further configured to detect cross-conduction between the first radio frequency source and the second radio frequency source based on the frequency domain analysis.

2. The electrosurgical generator according to claim 1, wherein, Each of the first controller and the second controller is further configured to shut down both the first radio frequency source and the second radio frequency source in response to the detection of the cross conduction.

3. The electrosurgical generator according to claim 1, wherein, The first radio frequency source further includes: a first active terminal connected to the first radio frequency inverter and further configured to be connected to a first electrosurgical instrument.

4. The electrosurgical generator according to claim 3, wherein, The second radio frequency source further includes: a second active terminal, which is connected to the second radio frequency inverter and is further configured to be connected to a second electrosurgical instrument.

5. The electrosurgical generator of claim 4, further comprising: a common return terminal configured to be coupled to at least one return electrode pad, the common return terminal being coupled to the first RF inverter and the second RF inverter.

6. The electrosurgical generator according to claim 5, wherein, The first radio frequency source further includes: a first isolation transformer having a primary winding connected to the first radio frequency inverter and a secondary winding connected to the first active terminal and the common return terminal.

7. The electrosurgical generator according to claim 6, wherein, The second radio frequency source further includes: a second isolation transformer having a primary winding connected to the second radio frequency inverter and a secondary winding connected to the second active terminal and the common return terminal.

8. An electrosurgical system comprising: First electrosurgical instrument; Second electrosurgical instrument; as well as An electrosurgical generator comprising: The first radio frequency source includes: A first power supply, which is configured to output a first DC waveform; A first radio frequency inverter, connected to the first power supply and the first electrosurgical instrument, is configured to supply a first radio frequency waveform having a first frequency from the first DC waveform to the first electrosurgical instrument, wherein the first radio frequency waveform has a first carrier frequency; and A first controller is configured to control the first radio frequency inverter; The second radio frequency source includes: A second power supply is configured to output a second DC waveform; A second radio frequency inverter, connected to the second power supply and the second electrosurgical instrument, is configured to generate a second radio frequency waveform from the second DC waveform to the second electrosurgical instrument simultaneously with the generation of the first radio frequency waveform, wherein the second radio frequency waveform has a second carrier frequency different from the first carrier frequency; and The second controller is configured to control the second radio frequency inverter. The electrosurgical generator further includes: a clock source connected to the first controller and the second controller, and configured to synchronize the operation of the first controller and the second controller; The first controller and the second controller are configured to perform frequency domain analysis on the first radio frequency waveform and the second radio frequency waveform, respectively, and each of the first controller and the second controller is further configured to detect cross-conduction between the first radio frequency source and the second radio frequency source based on the frequency domain analysis.

9. The electrosurgical system according to claim 8, wherein, Each of the first controller and the second controller is further configured to shut down both the first radio frequency source and the second radio frequency source in response to the detection of the cross conduction.

10. The electrosurgical system according to claim 9, wherein, The first radio frequency source further includes: a first active terminal connected to the first radio frequency inverter and further configured to be connected to a first electrosurgical instrument; and The second radio frequency source further includes: a second active terminal connected to the second radio frequency inverter and further configured to be connected to a second electrosurgical instrument.

11. The electrosurgical system of claim 10, further comprising: At least one return electrode pad, wherein the electrosurgical generator further includes: a common return terminal connected to the at least one return electrode pad and connected to the first RF inverter and the second RF inverter.

12. The electrosurgical system according to claim 11, wherein, The first radio frequency source further includes: a first isolation transformer having a primary winding connected to the first radio frequency inverter and a secondary winding connected to the first active terminal and the common return terminal; and The second radio frequency source further includes: a second isolation transformer having a primary winding connected to the second radio frequency inverter and a secondary winding connected to the second active terminal and the common return terminal.

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