Independent control of dual rf bipolar electrosurgery

Abstract

This disclosure relates to independent control of dual-RF bipolar electrosurgical procedures. An electrosurgical generator includes a first radio frequency source having: a first power supply configured to output a first DC waveform; a first radio frequency inverter coupled to the first power supply and configured to generate a first interrogation waveform and a first radio frequency waveform from the first DC waveform; and a first controller configured to control the first radio frequency inverter to output the first radio frequency waveform based on a response to the first interrogation waveform. The generator further includes a second radio frequency source having: a second power supply configured to output a second DC waveform; a second radio frequency inverter coupled to the second power supply and configured to generate the second interrogation waveform simultaneously with the first interrogation waveform, and to generate the second radio frequency waveform simultaneously with the first radio frequency waveform; and a second controller configured to control the second radio frequency inverter to output the second radio frequency waveform based on a response to the second interrogation waveform.

Description

[0001] Cross-reference to related applications

[0002] This application claims the benefit and priority of U.S. Provisional Patent Applications Nos. 63 / 028,012, 63 / 028,007, 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 bipolar electrosurgical devices for delivering two separate bipolar radiofrequency waveforms. 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 bipolar instruments. 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 RF sources. As used herein, cross-conduction is the current flowing through the contact impedance of an energy channel relative to the 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 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 interrogation waveform and a first RF waveform from the first DC waveform; and a first controller configured to control the first RF inverter to output the first RF waveform based on a response to the first interrogation waveform. The 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 interrogation waveform simultaneously with the first interrogation waveform, and to generate the second RF waveform simultaneously with the first RF waveform; and a second controller configured to control the second RF inverter to output the second RF waveform based on a response to the second interrogation waveform.

[0009] According to another embodiment of this disclosure, an electrosurgical system is disclosed. The system includes a first bipolar electrosurgical instrument and a second bipolar electrosurgical instrument. The system further includes an electrosurgical generator having a first radio frequency (RF) source, the first RF source comprising: a first power supply configured to output a first DC waveform; and a first RF inverter connected to the first power supply and the first bipolar electrosurgical instrument. The first RF inverter is configured to generate a first interrogation waveform and a first RF waveform from the first DC waveform. The first RF source further includes: a first controller configured to control the first RF inverter to output the first RF waveform based on a response to the first interrogation waveform. The generator further includes a second RF source having: a second power supply configured to output a second DC waveform; and a second RF inverter connected to the second power supply and the second bipolar electrosurgical instrument. The second RF inverter is configured to generate the second interrogation waveform simultaneously with the generation of the first interrogation waveform, and to generate the second RF waveform simultaneously with the generation of the first RF waveform. The second RF source further includes: a second controller configured to control the second RF inverter to output the second RF waveform based on a response to the second interrogation waveform.

[0010] According to any aspect of the above embodiments, each of the first interrogation waveform and the second interrogation waveform is a pulsed radio frequency waveform. The pulsed radio frequency waveform comprises a plurality of pulses with a duration of about 10 microseconds to about 1,000 microseconds and a repetition rate of about 10 milliseconds to about 50 milliseconds.

[0011] According to another aspect of any of the above embodiments, the first radio frequency source further includes at least one first sensor configured to measure a first impedance based on a first interrogation waveform. The first controller is further configured to determine contact between a first electrosurgical instrument coupled to the first radio frequency source and tissue based on a comparison of the first impedance with an open-circuit threshold. The first controller is further configured to control a first radio frequency inverter to output a first radio frequency waveform based on the comparison.

[0012] According to another aspect of any of the above embodiments, the second radio frequency source further includes at least one second sensor configured to measure a second impedance based on a second interrogation waveform. The second controller is further configured to determine contact between a second electrosurgical instrument coupled to the second radio frequency source and tissue based on a comparison of the second impedance with an open-circuit threshold. The second controller is further configured to control a second radio frequency inverter to output a second radio frequency waveform based on the comparison.

[0013] According to another aspect of any of the above embodiments, the generator further includes: a clock source coupled to the first controller and the second controller, and configured to synchronize the operation of the first controller and the second controller. 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 Based on 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 connected to 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;

[0021] Figure 7 This is an embodiment of the present disclosure for operation Figure 1 A flowchart of a method for detecting tissue contact during automatic bipolar mode using an electrosurgical generator; and

[0022] Figure 8 This is an embodiment of the present disclosure for operation Figure 1 A flowchart of a method for using an electrosurgical generator to detect overcurrent and / or cross-conduction. Detailed Implementation

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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, hemostasis, electrocautery, jetting, etc.) and procedures (e.g., monopolar, bipolar, vascular sealing).

[0027] refer to Figure 1The electrosurgical system 10 shown includes one or more bipolar electrosurgical instruments 20' and 20"". These bipolar electrosurgical instruments are shown as forceps, each having a pair of electrodes 23a' and 23b' and 23a" and 23b" respectively, for treating a patient's tissue. In an embodiment, the bipolar electrosurgical instruments 20' and 20" may be a pair of forceps. Instruments 20' and 20" are coupled to a generator 100 via cables 24' and 24"". The generator 100 is a dual-source RF generator configured to supply separate RF waveforms from individual RF sources to each of the instruments 20' and 20"".

[0028] 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 a return electrode pad. 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., bipolar 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.

[0029] Generator 100 is configured to operate in various modes and to output a bipolar waveform based on the selected mode. Each of these modes operates based on a pre-programmed power profile indicating how much power generator 100 outputs over a range of varying load (e.g., tissue) impedance. Each power profile includes power, voltage, and current control ranges defined by user-selected intensity settings and a measured minimum load impedance.

[0030] 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.

[0031] 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 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 first return terminal 212 and a second return terminal 312, respectively. Specifically, the electrosurgical energy used to power the bipolar electrosurgical instruments 20' and 20" is delivered through ports 114 and 116, each of which is connected to active terminal 210 and return terminal 212, and active terminal 310 and return terminal 312, respectively.

[0032] Active terminal 210 and return terminal 212 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 212. 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.

[0033] 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).

[0034] 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.

[0035] Each of controllers 204 and 304 is operatively connected to its respective power supply 206 and 306 and / or RF inverter 208 and 308, thereby allowing the processor to control the output of the first RF source 202 and the second 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 respectively adjust the DC and / or RF waveforms.

[0036] 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 terminals 212 and 312.

[0037] In other embodiments, 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.

[0038] 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, etc. 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.

[0039] 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 source 302 of the generator 100, and to control the outputs of the first RF source 202 and the second source 302 at least in part based 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.

[0040] 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 source 302 can be the same or different.

[0041] 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 distinguish 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 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 program (e.g., software instructions) executable by controllers 204 and 304.

[0042] 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.

[0043] 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 even / odd 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.

[0044] In embodiments where both the first and second RF waveforms are discontinuous, the limited frequency space may be constrained. Discontinuous waveforms can have repetition rates ranging from approximately 20 kHz to approximately 490 kHz. 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 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.

[0045] 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.

[0046] In embodiments where 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. Bandpass filters provide a signal passband 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.

[0047] Generator 100 is configured to operate in an automatic bipolar mode, during which each of the first RF source 202 and the second RF source 302 outputs any suitable bipolar RF waveform after tissue contact is detected. The user can configure each of the first RF source 202 and the second RF source 302 during this mode to set the power level and to set a delay time for initiating RF delivery after confirmation of tissue contact with the bipolar electrosurgical instruments 20' and 20"). In this mode, the generator outputs a low-power interrogation pulse waveform to measure impedance and determine tissue contact. The interrogation waveform can be from about 1W to about 5W and can have a duration from about 10 microseconds to about 1,000 microseconds, and can be repeated every 10 milliseconds to about 50 milliseconds. After detecting impedance indicating tissue contact, and after a user-selectable delay time, generator 100 outputs energy through the connected bipolar instruments 20' and 20"

[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 an automatic bipolar 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. The automatic bipolar mode RF waveform may be a discontinuous waveform. The user also configures each of the first RF source 202 and the second RF source 302 to include the power level of the RF waveform and a delay for generating the RF waveform after tissue contact is detected.

[0049] During operation, while the mode is active, each of the first RF source 202 and the second RF source 302 continuously outputs a first interrogation waveform and a second interrogation waveform. The first and second interrogation waveforms are separated and used by sensors 216 and 316 to measure the impedance (if present) of tissue contacted by each of the instruments 20' and 20" . Each of processors 204 and 304 continuously compares the impedance in response to the first and second interrogation waveforms to a predetermined threshold indicating the presence of a resistive load (e.g., not an open circuit), which may be 1,000 Ω. In other embodiments, the impedance may be compared to a low threshold indicating a short circuit, which may be from about 10 ohms (Ω) to about 50 Ω.

[0050] Processors 204 and 304 utilize signal processing techniques and / or time-division multiplexing techniques to distinguish between the simultaneously activated first and second interrogation waveforms. Processors 204 and 304 also determine the cross-conduction level between the first RF source 202 and the second RF source 302. The interrogation waveform carrier frequency allows for coherent sampling at a time-critical power calculation update rate, providing a combination of effective frequency discrimination and detection for cross-conduction. The carrier frequency ratio can vary between a Goertzel ratio of 45:50 and a Goertzel ratio of 49:51 to provide different response rates for tissue contact detection, i.e., differentiating from open circuits. Time-cascaded Goertzel calculations can also be used to provide smaller time intervals between power calculations for the algorithm.

[0051] In this embodiment, the optimal frequency for the first and second interrogation waveforms can be determined by scanning the frequency responses of the first RF source 202 and the second RF source 302 and identifying noise frequencies. After identifying the noise carrier frequencies, a quieter frequency is selected to avoid damage to the first and second interrogation waveforms, thereby avoiding false detection of tissue contact.

[0052] In other embodiments, the pulses of the first and second interrogation waveforms can be time-spaced so that they do not overlap. Since the duration of each pulse of the first and second interrogation waveforms (e.g., from about 10 microseconds to about 1,000 microseconds) is less than the off-time between pulses (e.g., from about 10 milliseconds to about every 50 milliseconds), the pulses can be synchronized with any time slot within the off-time period of the other waveform, so that the pulses do not occur simultaneously.

[0053] refer to Figure 8A method for monitoring the output of a first RF source 202 and a second RF source 302 includes interrogation waveforms for overcurrent and crossconduction and RF bipolar waveforms. Once processors 204 and 304 confirm that instruments 20' and 20" are in contact with tissue, processors 204 and 304 signal the first RF source 202 and / or the second RF source 302 to output first and second bipolar RF waveforms to treat the tissue, depending on which of the instruments 20' or 20" is in contact with the tissue. Therefore, if based on Figure 7 If the detection method confirms that only one of the devices 20' or 20" is in contact with the tissue, then only the corresponding first RF source 202 or second RF source 302 is energized to output a bipolar waveform to treat the tissue. The other of the first RF source 202 or second RF source 302 remains in interrogation mode until the user exits the automatic bipolar mode or tissue contact is detected.

[0054] If both interrogation waveforms confirm tissue contact, the first and second bipolar RF waveforms can be provided simultaneously. During the simultaneous transmission of the bipolar RF waveforms, sensors 216 and 316 measure the characteristics of the first and second RF waveforms. The bipolar RF waveform carrier frequency and coagulation repetition rate can be selected to provide coherent sampling at the time-critical power calculation update rate.

[0055] Sensors 216 and 316, in conjunction with corresponding controllers 204 and 304, perform broadband measurements on each of the first and second RF waveforms, while simultaneously detecting cross-conduction between the first RF source 202 and the second RF source 302.

[0056] 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 bipolar RF operation. Specifically, upon detection of cross-conduction by either controller 204 or 304, each of controllers 204 and 304 is configured to output a warning and / or shut down both the first RF source 202 and the second RF source 302 in response to a cross-conduction dose error.

[0057] 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 is connected to the first power supply and is configured to generate a first interrogation waveform and a first radio frequency waveform from the first DC waveform; as well as A first controller is configured to control the first radio frequency inverter to output the first radio frequency waveform based on the response of the first interrogation waveform; as well as The second radio frequency source includes: A second power supply is configured to output a second DC waveform; A second radio frequency inverter is connected to the second power supply and is configured to generate a second interrogation waveform at the same time as the first interrogation waveform is generated, and to generate a second radio frequency waveform at the same time as the first radio frequency waveform is generated. A second controller is configured to control the second radio frequency inverter to output the second radio frequency waveform based on the response of the second interrogation waveform; as well as A clock source, connected to the first controller and the second controller, is configured to generate clock signals to synchronize the operation of the first controller and the second controller, wherein each of the first interrogation waveform and the second interrogation waveform is based on the clock signal. The first controller and the second controller are further configured to determine the cross-conduction level between the first radio frequency source and the second radio frequency source.

2. The electrosurgical generator according to claim 1, wherein, Each of the first interrogation waveform and the second interrogation waveform is a pulse radio frequency waveform.

3. The electrosurgical generator according to claim 2, wherein, The pulsed radio frequency waveform comprises multiple pulses with a duration of 10 microseconds to 1,000 microseconds and a repetition rate of 10 milliseconds to 50 milliseconds.

4. The electrosurgical generator according to claim 1, wherein, The first radio frequency source further includes at least one first sensor configured to measure a first impedance based on the first interrogation waveform.

5. The electrosurgical generator according to claim 4, wherein, The first controller is further configured to determine the contact between the first electrosurgical instrument coupled to the first radio frequency source and the tissue based on a comparison of the first impedance with an open-circuit threshold.

6. The electrosurgical generator according to claim 5, wherein, The first controller is further configured to control the first RF inverter to output the first RF waveform based on the comparison.

7. The electrosurgical generator according to claim 6, wherein, The second radio frequency source further includes at least one second sensor configured to measure the second impedance based on the second interrogation waveform.

8. The electrosurgical generator according to claim 7, wherein, The second controller is further configured to determine the contact between the second electrosurgical instrument coupled to the second radio frequency source and the tissue based on a comparison of the second impedance with an open-circuit threshold.

9. The electrosurgical generator according to claim 8, wherein, The second controller is further configured to control the second RF inverter to output the second RF waveform based on the comparison.

10. An electrosurgical system comprising: The first bipolar electrosurgical instrument; Second bipolar electrosurgical instrument; as well as 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 is connected to the first power supply and the first bipolar electrosurgical instrument, and the first radio frequency inverter is configured to generate a first interrogation waveform and a first radio frequency waveform from the first DC waveform. as well as A first controller is configured to control the first radio frequency inverter to output the first radio frequency waveform based on the response of the first interrogation waveform; as well as The second radio frequency source includes: A second power supply is configured to output a second DC waveform; A second radio frequency inverter is connected to the second power supply and the second bipolar electrosurgical instrument. The second radio frequency inverter is configured to generate a second interrogation waveform while generating the first interrogation waveform, and to generate a second radio frequency waveform while generating the first radio frequency waveform. A second controller is configured to control the second radio frequency inverter to output the second radio frequency waveform based on the response of the second interrogation waveform; as well as A clock source, connected to the first controller and the second controller, is configured to generate clock signals to synchronize the operation of the first controller and the second controller, wherein each of the first interrogation waveform and the second interrogation waveform is based on the clock signal. The first controller and the second controller are further configured to determine the cross-conduction level between the first radio frequency source and the second radio frequency source.

11. The electrosurgical system according to claim 10, wherein, Each of the first interrogation waveform and the second interrogation waveform is a pulse radio frequency waveform.

12. The electrosurgical system according to claim 11, wherein, The pulsed radio frequency waveform comprises multiple pulses with a duration of 10 microseconds to 1,000 microseconds and a repetition rate of 10 milliseconds to 50 milliseconds.

13. The electrosurgical system according to claim 10, wherein, The first radio frequency source further includes at least one first sensor configured to measure a first impedance based on the first interrogation waveform.

14. The electrosurgical system according to claim 13, wherein, The first controller is further configured to determine the contact between the first bipolar electrosurgical instrument coupled to the first radio frequency source and the tissue based on a comparison of the first impedance with an open-circuit threshold.

15. The electrosurgical system according to claim 14, wherein, The first controller is further configured to control the first RF inverter to output the first RF waveform based on the comparison.

16. The electrosurgical system according to claim 15, wherein, The second radio frequency source further includes at least one second sensor configured to measure the second impedance based on the second interrogation waveform.

17. The electrosurgical system according to claim 16, wherein, The second controller is further configured to determine the contact between the second bipolar electrosurgical instrument coupled to the second radio frequency source and the tissue based on a comparison of the second impedance with an open-circuit threshold.

18. The electrosurgical system according to claim 17, wherein, The second controller is further configured to control the second RF inverter to output the second RF waveform based on the comparison.

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