Independent control of dual RF electrosurgery

Abstract

To provide a single electrosurgical generator capable of outputting simultaneous RF waveforms and capable of providing independent control of multiple ports.SOLUTION: An electrosurgical generator comprises a first radio frequency source including: 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 monopolar radio frequency waveform from the first direct current waveform; and a first controller configured to control the first radio frequency inverter to output the monopolar radio frequency waveform. The generator also comprises a second radio frequency source including: 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 bipolar radio frequency waveform simultaneously with the monopolar radio frequency waveform; and a second controller configured to control the second radio frequency inverter to output the bipolar radio frequency waveform.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of and priority to U.S. Provisional Patent Application Nos. 63 / 028,049, 63 / 028,009, 63 / 028,012, and 63 / 028,007, each of which was filed on May 21, 2020. The entire contents of each of the foregoing applications are incorporated herein by reference.

[0002] background FIELD OF THE DISCLOSURE The present disclosure relates to systems and methods for controlling electrosurgical generators. In particular, the present disclosure relates to controlling multiple electrosurgical devices each delivering a distinct monopolar and / or bipolar radio frequency waveform. [Background technology]

[0003] Electrosurgery involves the application of high radio frequency electrical current to a surgical site to cut, ablate, desiccate, or coagulate tissue. In monopolar electrosurgery, a source or active electrode delivers radio frequency alternating current from the electrosurgical generator to the target tissue. A patient return electrode is positioned remotely from the active electrode to carry the current back to the generator.

[0004] In bipolar electrosurgery, a return electrode and an active electrode are placed in close proximity to one another, resulting in an electrical circuit between the two electrodes (e.g., in the case of electrosurgical forceps). In this manner, the applied current is confined to the body tissue positioned between the electrodes. Thus, bipolar electrosurgery generally involves the use of equipment where it is desired to achieve a focused delivery of electrosurgical energy between the two electrodes.

[0005] The current solution for dual-site surgery, i.e., the simultaneous use of two electrosurgical devices, generally involves the use of two electrosurgical generators. This solution is inherently cumbersome and cost-prohibitive. Therefore, a need exists for independent control of multiple ports of a single electrosurgical generator capable of outputting simultaneous RF waveforms. Summary of the Invention [Means for solving the problem]

[0006] The present disclosure provides an electrosurgical system including 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. The individual RF waveforms are supplied to corresponding electrosurgical devices, which may be monopolar or bipolar. Each of the sources is controlled by its own controller, each coupled to a common clock source. The electrosurgical generator performs wideband measurements of each source's discontinuous or continuous signal and simultaneously detects transconductance and crosstalk between the RF sources. As used herein, transconductance is the current of an energy channel flowing through the contact impedance of the opposing channel, and crosstalk is the radiated interference between energy channels within the electrosurgical generator.

[0007] According to one embodiment of the present disclosure, an electrosurgical generator is disclosed. The 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 monopolar radio frequency waveform from the first DC waveform, and a first controller configured to control the first radio frequency inverter to output the monopolar radio frequency waveform. The generator also 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 a bipolar radio frequency waveform simultaneously with the monopolar radio frequency waveform, and a second controller configured to control the second radio frequency inverter to output the bipolar radio frequency waveform.

[0008] According to one aspect of the above embodiment, the generator further includes a clock source coupled to the first controller and the second controller and configured to synchronize sampling operations of the first controller and the second controller. The monopolar radio frequency waveform has a first frequency, and the bipolar 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 of the monopolar radio frequency waveform and the bipolar radio frequency waveform, respectively. Each of the first controller and the second controller is further configured to detect transconductance 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 at least one of issue an alarm or shut off both the first radio frequency source and the second radio frequency source in response to detecting the transconductance.

[0009] According to another aspect of the above embodiment, the first radio frequency source further includes a first active terminal coupled to the first radio frequency inverter and further configured to couple to a monopolar electrosurgical instrument. The second radio frequency source further includes a second active terminal and a second return terminal coupled to the second radio frequency inverter and further configured to couple to a bipolar electrosurgical instrument. The first radio frequency source further includes a first return terminal configured to couple to at least one return electrode pad, the first return terminal being coupled to the first radio frequency inverter and the second radio frequency inverter. The first radio frequency source further includes a first isolation transformer having a primary winding coupled to the first radio frequency inverter and a secondary winding coupled to the first active terminal and the return terminal. The second radio frequency source further includes a second isolation transformer having a primary winding coupled to the second radio frequency inverter and a secondary winding coupled to the second active terminal and the second return terminal.

[0010] According to another embodiment of the present disclosure, an electrosurgical system is disclosed. The system includes a monopolar electrosurgical device, a bipolar electrosurgical device, and an electrosurgical generator. The generator includes a first radio frequency source having a first power supply configured to output a first DC waveform and a first radio frequency inverter coupled to the first power supply and the monopolar electrosurgical device. The first radio frequency inverter is configured to supply a monopolar radio frequency waveform having a first frequency from the first DC waveform to the monopolar electrosurgical device. The first radio frequency source also includes a first controller configured to control the first radio frequency inverter. The generator also includes a second radio frequency source having a second power supply configured to output a second DC waveform and a second radio frequency inverter coupled to the second power supply and the bipolar electrosurgical device. The second radio frequency inverter is configured to simultaneously generate a bipolar radio frequency waveform from the second DC waveform to the bipolar electrosurgical device and the monopolar radio frequency waveform. The second radio frequency source also includes a second controller configured to control the second radio frequency inverter.

[0011] According to one aspect of the above embodiment, the electrosurgical generator further includes a clock source coupled to the first controller and the second controller and configured to synchronize sampling operations of the first controller and the second controller. The monopolar radio frequency waveform has a first frequency, and the bipolar 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 of the monopolar radio frequency waveform and the bipolar radio frequency waveform, respectively. Each of the first controller and the second controller is further configured to detect transconductance 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 at least one of issue an alarm or shut off both the first radio frequency source and the second radio frequency source in response to detecting the transconductance.

[0012] According to another aspect of the above embodiment, the first radio frequency source further includes a first active terminal coupled to the first radio frequency inverter and configured to couple to a monopolar electrosurgical instrument. The second radio frequency source further includes a second active terminal coupled to the second radio frequency inverter and further configured to couple to a bipolar electrosurgical instrument. The electrosurgical system further includes at least one return electrode pad, and the electrosurgical generator further includes a first return terminal coupled to the at least one return electrode pad and to the first radio frequency inverter and the second radio frequency inverter. The first radio frequency source further includes a first isolation transformer having a primary winding coupled to the first radio frequency inverter and a secondary winding coupled to the first active terminal and the first return terminal. The second radio frequency source further includes a second isolation transformer having a primary winding coupled to the second radio frequency inverter and a secondary winding coupled to the second active terminal and the second return terminal. For example, the present application provides the following: (Item 1) 1. An electrosurgical generator comprising: a first radio frequency source, a first power supply configured to output a first DC waveform; a first radio frequency inverter coupled to the first power source and configured to generate a unipolar radio frequency waveform from the first DC waveform; and a first radio frequency source including a first controller configured to control the first radio frequency inverter to output the unipolar radio frequency waveform; a second radio frequency source, a second power supply configured to output a second DC waveform; a second radio frequency inverter coupled to the second power source and configured to generate a bipolar radio frequency waveform simultaneously with the unipolar radio frequency waveform; and a second radio frequency source including a second controller configured to control the second radio frequency inverter to output the bipolar radio frequency waveform. (Item 2) The electrosurgical generator described in the preceding item, further comprising a clock source coupled to the first controller and the second controller and configured to synchronize operation of the first controller and the second controller. (Item 3) 10. The electrosurgical generator of claim 9, wherein the monopolar radio frequency waveform has a first frequency and the bipolar radio frequency waveform has a second frequency different from the first frequency. (Item 4) 10. The electrosurgical generator of claim 9, wherein the first controller and the second controller are configured to perform frequency domain analysis of the monopolar radio frequency waveform and the bipolar radio frequency waveform, respectively. (Item 5) 10. The electrosurgical generator of claim 9, wherein each of the first controller and the second controller is further configured to detect a mutual conductance between the first radio frequency source and the second radio frequency source based on the frequency domain analysis. (Item 6) 10. The electrosurgical generator of claim 9, wherein each of the first controller and the second controller is further configured to at least one of issue an alarm or shut off both the first radio frequency source and the second radio frequency source in response to detecting the mutual conductance. (Item 7) 10. The electrosurgical generator of claim 9, wherein the first radio frequency source is coupled to the first radio frequency inverter and further includes a first active terminal further configured to be coupled to a monopolar electrosurgical instrument. (Item 8) 10. The electrosurgical generator of claim 9, wherein the second radio frequency source is coupled to the second radio frequency inverter and further includes a second active terminal and a second return terminal further configured to be coupled to a bipolar electrosurgical instrument. (Item 9) 10. The electrosurgical generator of claim 9, wherein the first radio frequency source further includes a first return terminal configured to couple to at least one return electrode pad, the first return terminal being coupled to the first radio frequency inverter and the second radio frequency inverter. (Item 10) 10. The electrosurgical generator of claim 9, wherein the first radio frequency source further includes a first isolation transformer having a primary winding coupled to the first radio frequency inverter and a secondary winding coupled to the first active terminal and the return terminal. (Item 11) 10. The electrosurgical generator of claim 9, wherein the second radio frequency source further includes a second isolation transformer having a primary winding coupled to the second radio frequency inverter and a secondary winding coupled to the second active terminal and the second return terminal. (Item 12) 1. An electrosurgical system comprising: a monopolar electrosurgical device; a bipolar electrosurgical device; 1. An electrosurgical generator comprising: a first radio frequency source, a first power supply configured to output a first DC waveform; a first radio frequency inverter coupled to the first power source and the monopolar electrosurgical instrument, the first radio frequency inverter configured to supply a monopolar radio frequency waveform having a first frequency from the first DC waveform to the monopolar electrosurgical instrument; and a first radio frequency source including a first controller configured to control the first radio frequency inverter; a second radio frequency source, a second power supply configured to output a second DC waveform; a second radio frequency inverter coupled to the second power source and the bipolar electrosurgical instrument, the second radio frequency inverter configured to generate a bipolar radio frequency waveform from the second DC waveform for the bipolar electrosurgical instrument simultaneously with the monopolar radio frequency waveform; and an electrosurgical generator including a second radio frequency source including a second controller configured to control the second radio frequency inverter; and (Item 13) The electrosurgical system described in the preceding item, wherein the electrosurgical generator further includes a clock source coupled to the first controller and the second controller and configured to synchronize operation of the first controller and the second controller. (Item 14) 10. The electrosurgical system of claim 1, wherein the monopolar radio frequency waveform has a first frequency and the bipolar radio frequency waveform has a second frequency different from the first frequency. (Item 15) The electrosurgical system of any one of the preceding items, wherein the first controller and the second controller are configured to perform frequency domain analysis of the monopolar radio frequency waveform and the bipolar radio frequency waveform, respectively. (Item 16) The electrosurgical system of any one of the preceding items, wherein each of the first controller and the second controller is further configured to detect a mutual conductance between the first radio frequency source and the second radio frequency source based on the frequency domain analysis. (Item 17) The electrosurgical system of any one of the preceding items, wherein each of the first controller and the second controller is further configured to do at least one of issuing an alarm or shutting off both the first radio frequency source and the second radio frequency source in response to detecting the mutual conductance. (Item 18) the first radio frequency source further includes a first active terminal coupled to the first radio frequency inverter and further configured to couple to a monopolar electrosurgical instrument; The electrosurgical system of any one of the preceding items, wherein the second radio frequency source is coupled to the second radio frequency inverter and further includes a second active terminal further configured to be coupled to a bipolar electrosurgical instrument. (Item 19) 10. The electrosurgical system of claim 9, further comprising at least one return electrode pad, wherein the electrosurgical generator further includes a first return terminal coupled to the at least one return electrode pad, the first radio frequency inverter, and the second radio frequency inverter. (Item 20) the first radio frequency source further includes a first isolation transformer having a primary winding coupled to the first radio frequency inverter and a secondary winding coupled to the first active terminal and the first return terminal; The electrosurgical system of any one of the preceding items, wherein the second radio frequency source further includes a second isolation transformer having a primary winding coupled to the second radio frequency inverter and a secondary winding coupled to the second active terminal and the second return terminal. (Summary) The 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 monopolar radio frequency waveform from the first DC waveform, and a first controller configured to control the first radio frequency inverter to output the monopolar radio frequency waveform. The generator also 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 a bipolar radio frequency waveform simultaneously with the monopolar radio frequency waveform, and a second controller configured to control the second radio frequency inverter to output the bipolar radio frequency waveform. [Brief explanation of the drawings]

[0013] The present disclosure can be understood by reference to the accompanying drawings when considered in conjunction with the following detailed description.

[0014] [Figure 1] FIG. 1 is a perspective view of an electrosurgical system according to one embodiment of the present disclosure; [Figure 2] FIG. 2 is a front view of the dual RF source electrosurgical generator of FIG. 1 in accordance with an embodiment of the present disclosure. [Figure 3] FIG. 2 is a schematic diagram of the electrosurgical generator of FIG. 1 coupled to two monopolar electrosurgical instruments and a shared return electrode pad, according to an embodiment of the present disclosure. [Figure 4] FIG. 2 is a schematic diagram of the electrosurgical generator of FIG. 1 coupled to two bipolar electrosurgical instruments, according to an embodiment of the present disclosure. [Figure 5] FIG. 2 is a schematic diagram of the electrosurgical generator of FIG. 1 coupled to a monopolar electrosurgical instrument, a return electrode pad, and a bipolar electrosurgical instrument, according to an embodiment of the present disclosure. [Figure 6] 2 is a schematic diagram of a clock source coupled to a first controller of a first RF source and a second controller of a second RF source of the electrosurgical generator of FIG. 1 in accordance with the present disclosure; FIG. [Figure 7] 2 is a frequency response plot of a continuous RF waveform produced by the electrosurgical generator of FIG. 1 in accordance with the present disclosure. [Figure 8] 2 is a frequency response plot of a discontinuous RF waveform produced by the electrosurgical generator of FIG. 1 in accordance with the present disclosure. [Figure 9] 2 is a flowchart of a method of operating the electrosurgical generator of FIG. 1 to detect overcurrent and / or transconductance, according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0015] Embodiments of the presently disclosed electrosurgical system will now be described in detail with reference to the drawings, in which like reference numerals indicate identical or corresponding elements in each of the several views. As used herein, the term "distal" refers to that portion of the associated surgical instrument that is closer to the patient, and the term "proximal" refers to that portion that is further from the patient.

[0016] The term "application" may include a computer program designed to perform a function, task, or activity for the benefit of a user. An application may refer to software that runs locally or remotely, for example, as a standalone program, or in a web browser, or other software that is understood by those skilled in the art to be an application. An application may run on a controller or on a user device, including, for example, a mobile device, an IoT device, a server system, or any programmable logic device.

[0017] In the following description, well-known functions or configurations are not described in detail to avoid obscuring the present disclosure in unnecessary detail. Those skilled in the art will understand that the present disclosure can be adapted for use with either endoscopic instruments, laparoscopic instruments, or open instruments. It should also be understood that different electrical and mechanical connections and other considerations may apply to each specific type of instrument.

[0018] Electrosurgical generators according to the present disclosure may be used in monopolar and / or bipolar electrosurgical procedures, including, for example, cutting, coagulation, ablation, and vessel sealing procedures. The generator may include multiple outputs for interfacing with various ultrasonic and electrosurgical instruments (e.g., ultrasonic dissectors and hemostats, monopolar instruments, return electrode pads, bipolar electrosurgical forceps, foot switches, etc.). Furthermore, the generator may include electronic circuitry configured to generate radio frequency energy particularly suitable for powering ultrasonic instruments and electrosurgical devices operating in various electrosurgical modes (e.g., cutting, mixing, coagulation, dividing with hemostasis, electrodisruption, spraying, etc.) and procedures (e.g., monopolar, bipolar, vessel sealing).

[0019] Referring to FIG. 1 , electrosurgical system 10 is shown including two or more of monopolar electrosurgical instruments 20′ and 20″ and / or bipolar electrosurgical instruments 30′ and 30″. Monopolar electrosurgical instruments 20′ and 20″ include one or more active electrodes 23′ and 23″ (e.g., electrosurgical cutting probes, ablation electrode(s), etc.) for treating patient tissue. System 10 may include multiple return electrode pads 26 that are placed on the patient during use to maximize the overall contact area with the patient and thereby minimize the potential for tissue damage. Electrosurgical alternating RF current is supplied to instruments 20′ and 20″ by generator 100 via supply lines 24′ and 24″. 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″. The alternating RF current is returned to generator 100 through return electrode pad 26 via return line 28. Additionally, generator 100 and return electrode pad 26 may be configured to monitor tissue and patient contact to ensure sufficient contact exists therebetween.

[0020] Bipolar electrosurgical instruments 30' and 30" are shown as forceps having pairs of electrodes 33a' and 33b' and 33a" and 33b", respectively, for treating patient tissue. In an embodiment, bipolar electrosurgical instruments 30' and 30" may be a pair of forceps. Instruments 30' and 30" are coupled to generator 100 via cables 34' and 34". Generator 100 is a dual-source RF generator configured to supply separate RF waveforms to each of instruments 30' and 30" from individual RF sources.

[0021] Referring to FIG. 2 , a front face 102 of generator 100 is shown. Generator 100 may include multiple ports 110, 112, 114, 116 for accommodating various types of electrosurgical instruments, and port 118 for coupling to return electrode pad 26. Ports 110 and 112 are configured to couple to monopolar electrosurgical instruments 20′ and 20″. Ports 114 and 116 are configured to couple to bipolar electrosurgical instruments 30′ and 30″. Generator 100 includes a display 120 for providing various output information (e.g., intensity settings, treatment completion indicators, etc.) to a user. Display 120 is a touchscreen configured to display menus corresponding to instruments (e.g., monopolar electrosurgical instruments 20′ and 20″, bipolar electrosurgical instruments 30′ and 30″, electrosurgical forceps, etc.). A user also adjusts inputs by simply touching the corresponding menu option. The generator 100 includes suitable input controls 122 (eg, buttons, activators, switches, touch screen, etc.) for controlling the generator 100 .

[0022] The generator 100 is configured to operate in various modes and to output unipolar and / or bipolar waveforms based on the mode selected for each of the ports 110, 112, 114, 116. Each mode operates based on a pre-programmed power curve that determines how much power is output by the generator 100 at various ranges of impedance of the load (e.g., tissue). Each power curve includes control ranges for power, voltage, and current defined by the user-selected intensity setting and the minimum measured impedance of the load.

[0023] The generator 100 can operate in the following monopolar modes, including but not limited to cutting, mixing, dividing with hemostasis, electrodisruption, and spraying. The generator 100 can operate in the following bipolar modes, including bipolar coagulation, autobipolar that operates in response to the detection of tissue contact, and various algorithm-controlled vessel sealing modes.

[0024] Each of the first and second RF waveforms may be either a monopolar or bipolar RF waveform, each of which may be either continuous or discontinuous and may have a carrier frequency of about 200 kHz to about 500 kHz. As used herein, a continuous waveform is a waveform having a 100% duty cycle. In embodiments, a continuous waveform is used to provide a cutting effect on tissue. Conversely, a discontinuous waveform is a waveform having a non-continuous duty cycle, for example, less than 100%. In embodiments, a discontinuous waveform is used to provide a coagulation effect on tissue.

[0025] In the cutting mode, the generator 100 may deliver a continuous sinusoidal waveform at a predetermined carrier frequency (e.g., 472 kHz) with a crest factor of approximately 1.5 into an impedance of approximately 100 Ω to approximately 2000 Ω. The cutting mode power curve may include three regions: constant current into low impedance, constant power into medium impedance, and constant voltage into high impedance. In the mixed mode, the generator may deliver bursts of a sinusoidal waveform at a predetermined frequency, with the bursts reoccurring at a first predetermined rate (e.g., approximately 26.21 kHz). In one embodiment, the duty cycle of the bursts may be approximately 50%. The crest factor of one cycle of the sinusoidal waveform may be approximately 1.5. The crest factor of the bursts may be approximately 2.7.

[0026] The hemostasis mode may include a burst of a sinusoidal waveform at a predetermined frequency (e.g., 472 kHz) recurring at a second predetermined rate (e.g., about 28.3 kHz). The duty cycle of the burst may be about 25%. The crest factor of one burst may be about 4.3 for an impedance range of about 100 Ω to about 2000 Ω. The lightning disruption mode may include a burst of a sinusoidal waveform at a predetermined frequency (e.g., 472 kHz) recurring at a third predetermined rate (e.g., about 30.66 kHz). The duty cycle of the burst may be about 6.5% and the crest factor of one burst cycle may be about 5.55 for an impedance range of about 100 Ω to about 2000 Ω. The spray mode may include a burst of a sinusoidal waveform at a predetermined frequency (e.g., 472 kHz) recurring at a fourth predetermined rate (e.g., about 21.7 kHz). The duty cycle of the burst may be about 4.6%, and the crest factor of one burst cycle may be about 6.6 in an impedance range of about 100 Ω to about 2,000 Ω.

[0027] 3-5, generator 100 includes a dual-source RF architecture in which each RF source is supplied by a separate RF inverter, each powered by a separate DC power source. More specifically, generator 100 includes first and second RF sources 202 and 302. Each of sources 202 and 302 includes a first and second controller 204 and 304, a first and second power source 206 and 306, and a first and second RF inverter 208 and 308. Power sources 206 and 306 may be high-voltage DC power sources connected to a common AC power source (e.g., line voltage) and provide high-voltage DC power to respective RF inverters 208 and 308, which then convert the DC power to first and second RF waveforms through respective active terminals 210 and 310.

[0028] System 10 is shown in various configurations, with generator 100 operating with any combination of monopolar and bipolar electrosurgical instruments 20′, 20″, 30′, and 30″. Generator 100 includes a dual-source RF architecture in which each RF source is supplied by a separate RF inverter, each powered by a separate DC power supply. More specifically, generator 100 includes first RF source 202 and second source 302. First RF source 202 energizes ports 110 and 114, and second RF source 302 energizes ports 112 and 116. Port 118 is shared between first RF source 202 and second RF source 302.

[0029] Each of sources 202 and 302 includes first and second controllers 204 and 304, first and second power supplies 206 and 306, and first and second RF inverters 208 and 308. Power supplies 206 and 306 may be high-voltage DC power supplies connected to a common AC power source (e.g., line voltage) and provide high-voltage DC power to respective RF inverters 208 and 308, which then convert the DC power to first and second RF waveforms through respective active terminals 210 and 310. RF energy is returned thereto via first and second return terminals 212 and 312, respectively.

[0030] The active terminal 210 and the return terminal 212 are coupled to the RF inverter 208 through an isolation transformer 214. The isolation transformer 214 includes a primary winding 214a coupled to the RF inverter 208 and a secondary winding 214b coupled to the active terminal 210 and the return terminal 212. Similarly, the active terminal 310 and the return terminal 312 are coupled to the RF inverter 308 through an isolation transformer 314. The isolation transformer 314 includes a primary winding 314a coupled to the RF inverter 308 and a secondary winding 314b coupled to the active terminal 310 and the return terminal 312.

[0031] Referring to FIG. 3 , generator 100 is shown in a dual monopolar configuration for use with monopolar electrosurgical instruments 20′ and 20″, where electrosurgical energy for energizing monopolar electrosurgical instruments 20′ and 20″ is delivered through ports 110 and 112, respectively, which are each coupled to active terminals 210 and 310, respectively. RF energy is returned through return electrode pad 26 coupled to port 118, which in turn is coupled to a shared return terminal 313 coupled to return terminals 210 and 312. Secondary winding 214b of isolation transformer 214 is coupled to active terminal 210 and return terminal 212. Similarly, secondary winding 314b of isolation transformer 314 is coupled to active terminal 310 and return terminal 312.

[0032] Referring to FIG. 4, generator 100 is shown in a dual bipolar configuration for use with bipolar electrosurgical instruments 30′ and 30″, where RF energy for energizing bipolar electrosurgical instruments 30′ and 30″ is delivered through ports 114 and 116, each of which is coupled to active and return terminals 210 and 212, and active and return terminals 310 and 312, respectively.

[0033] FIG. 5 shows generator 100 in a combined monopolar / bipolar configuration for use with a monopolar electrosurgical device 20′ and a bipolar electrosurgical device 30′. Electrosurgical energy for energizing monopolar electrosurgical device 20′ and bipolar electrosurgical device 30′ is delivered through ports 110 and 116, respectively. In embodiments, a monopolar electrosurgical device 20′ may be coupled to the other monopolar port 112, and similarly, a bipolar electrosurgical device 30′ may be coupled to the other bipolar port 114. In the case of a monopolar electrosurgical device 20′, RF energy is returned through return electrode pad 26 coupled to port 118, which is in turn coupled to return terminal 212. In the case of a bipolar electrosurgical device 30′, energy is returned through the same port 116 via return terminal 312.

[0034] The generator 100 may include multiple steering relays or other switching devices configured to couple the active terminals 210 and 310 and the return terminals 212 and 312 to various ports 110, 112, 114, 116, 118, such as coupling the first return terminal 212 and the second return terminal 312 to a shared return terminal 313 in a dual monopolar configuration through a steering relay 315, based on the combination of monopolar electrosurgical devices 20′, 20″ and bipolar electrosurgical devices 30′, 30″ being used ( FIG. 3 ).

[0035] 3-5 , RF inverters 208 and 308 are configured to operate in multiple modes during which generator 100 outputs corresponding waveforms having particular duty cycles, peak voltages, crest factors, etc. It is contemplated that in other embodiments, generator 100 may be based on other types of suitable power supply topologies. RF inverters 208 and 308 may be resonant RF amplifiers, as shown, or non-resonant RF amplifiers. A non-resonant RF amplifier, as used herein, refers to an amplifier lacking conditioning components, i.e., conductors, capacitors, etc., disposed between the RF inverter and a load, e.g., tissue.

[0036] The controllers 204 and 304 may include a processor (not shown) operatively connected to a memory (not shown), which may include one or more of volatile, nonvolatile, magnetic, optical, or electrical media, such as read-only memory (ROM), random-access memory (RAM), electrically erasable programmable ROM (EEPROM), nonvolatile 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 in this disclosure, including, but not limited to, a hardware processor, a field-programmable gate array (FPGA), a digital signal processor (DSP), a central processing unit (CPU), a microprocessor, and combinations thereof. Those skilled in the art will understand that the processor may be substituted by using any logical processor (e.g., control circuitry) adapted to perform the calculations and / or instruction sets described herein.

[0037] Each of the controllers 204 and 304 is operatively connected to a respective power source 206 and 306 and / or RF inverter 208 and 308, allowing a processor to control the output of the first RF source 202 and second source 302 of the generator 100 according to either an open and / or closed control loop scheme. A 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 the controllers 204 and 304. The controllers 204 and 304 then control the respective power source 206 and 306 and / or RF inverter 208 and 308, respectively, which adjust the DC and / or RF waveforms.

[0038] A generator 100 according to the present disclosure may also include multiple sensors 216 and 316 that respectively monitor the output of the first RF source 202 and the second RF source 302 of the generator 100. The sensors 216 and 316 may be any suitable voltage, current, power, and impedance sensors. In the embodiment shown in FIGS. 3-5 , the sensor 216 is coupled to leads 220a and 220b of the RF inverter 208. The leads 220a and 220b couple the RF inverter 208 to the primary winding 214a of the transformer 214. The sensor 316 is coupled to leads 320a and 320b of the RF inverter 308. The leads 320a and 320b couple the RF inverter 308 to the primary winding 314a of the transformer 314. Thus, 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 .

[0039] In further embodiments, sensors 216 and 316 may be coupled to power sources 206 and 306 and configured to sense characteristics of the DC current supplied to RF inverters 208 and 308. Controllers 204 and 304 also receive input signals from display 120 and input controls 122 of generator 100 and / or equipment 30′ and 30″. Controllers 204 and 304 adjust the power output by generator 100 and / or perform other control functions for generator 100 in response to the input signals.

[0040] RF inverters 208 and 308 include multiple switching elements 228a-228d and 328a-328d, respectively, arranged in an H-bridge topology. In embodiments, RF inverters 208 and 308 may be configured according to any suitable topology, including, but not limited to, half-bridge, full-bridge, push-pull, etc. Suitable switching elements include voltage-controlled devices such as transistors, field-effect transistors (FETs), combinations thereof, etc. In embodiments, the FETs may be formed from gallium nitride, aluminum nitride, boron nitride, silicon carbide, or any other suitable wide bandgap material.

[0041] Controllers 204 and 304 are in communication with the respective RF inverters 208 and 308, particularly switching elements 228a-228d and 328a-328d. Controllers 204 and 304 are configured to output control signals, which may be pulse-width modulated ("PWM") signals, to switching elements 228a-228d and 328a-328d. In particular, controller 204 is configured to modulate control signal d1 provided to switching elements 228a-228d of RF inverter 208, and controller 304 is configured to modulate control signal d2 provided 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, the controllers 204 and 304 are configured to calculate power characteristics of the output of the first RF source 202 and the second source 302 of the generator 100 and control the output of the first RF source 202 and the second source 302 based at least in part on the measured power characteristics, including but not limited to, the voltage, current, and power at the output of the RF inverters 208 and 308.

[0042] 3-6 , each of the controllers 204 and 304 is coupled to a clock source 340 that acts as a common frequency source for each of the controllers 204 and 304, thus synchronizing the controllers 204 and 304. The clock source 340 is an electronic oscillator circuit that generates a clock signal for synchronizing the operation of the controllers 204 and 304. In particular, the sampling operations of the controllers 204 and 304 are synchronized. Each of the controllers 204 and 304 generates an RF waveform based on the clock signal from the clock source 340 and the selected mode. Thus, when a user selects one of the electrosurgical modes, each of the controllers 204 and 304 outputs first and second control signals that are used to control the respective RF inverters 208 and 308 to output first and second RF waveforms corresponding to the selected mode. The modes selected for each of the first RF source 202 and the second source 302, and the corresponding RF waveforms, may be the same or different.

[0043] The RF waveforms have different carrier frequencies, such that the first RF waveform has a first carrier frequency and the second RF waveform has a second carrier frequency. The two different carrier frequencies are selected to allow the controllers 204 and 304 to discriminate or separate measurement data in the frequency domain. The measurement data is collected by sensors 216 and 316 that monitor the output of the first RF source 202 and the second RF source 302. The controllers 204 and 304 analyze the respective first and second RF waveforms using any suitable bandpass technique or any technique that converts the measurement data to the frequency domain, such as a discrete Fourier transform (DFT) and a fast Fourier transform (FFT). In an embodiment, for continuous waveforms (e.g., those used during cutting mode), the controllers 204 and 304 may use an array of Goertzel filters oriented at the carrier frequency of the RF waveform and its harmonics. For discontinuous waveforms, the Goertzel filters are oriented at the repetition rate and harmonics of the repetition frequency of the waveform being analyzed. The filtering of the measurement data may be performed by an application, eg, software instructions, executable by the controllers 204 and 304 .

[0044] The frequencies of the first and second RF waveforms are selected to provide sufficient channel separation between the carrier frequencies of the first and second RF waveforms, as determined by a bandpass Goertzel filter. Referring to frequency response plot 350 of Figure 7, the frequency of the opposite RF port of the continuous waveform is selected to be at a null point in the frequency response. This maximizes source-to-source separation.

[0045] Referring to FIG. 8, a frequency response plot 360 of a discontinuous waveform is shown, in which separate Goertzel filters are applied to the fundamental repetition rate and the even and odd harmonics of the RF waveform being analyzed. Because the fundamental frequencies are not perfectly orthogonal, certain harmonic overlap exists. Overlapping sets of harmonics result in discontinuities in the Goertzel array plot. This is used to detect whether significant transconductance from one RF source is occurring at the sensor 216 or 316 of another RF source. If it is desired to isolate a source that contains combined information in only one of its harmonics, the unaffected harmonic is used in combination with a certain percentage of the affected harmonic. The separate transconductance information is used as a dose monitor to detect excessive transconductance conditions.

[0046] In embodiments in which both the first and second RF waveforms are discontinuous, the limited frequency space can be restrictive. The discontinuous waveforms may have repetition rates ranging from about 20 KHz to about 490 KHz. The repetition rates do not provide a perfectly orthogonal solution from a signal processing perspective. The technique for determining the power values ​​of each of the first RF source 202 and second source 302 to be used for independent control depends on the level of transconductance. The transconductance causes actual power to be stored in the contact impedance. Therefore, the controlled power is based on the sum of the transconductance power stored at the contact impedance and the port source power stored in the contact impedance. In embodiments, non-contact tissue impedance and the power stored in the return electrode pad 26 may also be included in the overall calibration of a particular RF port. If frequency discrimination is used for power control, before using generator 100, instruments 30' and 30" and return electrode pad 26 are subjected to a calibration procedure that takes into account both cable compensation of cables 34' and 34" and return line 28, as well as harmonic overlap and transconductance. Transconductance may also be monitored as a mitigation measure for potential dose error.

[0047] In an embodiment, where one of the first and second RF waveforms is continuous and the other is discontinuous, the continuous RF waveform may be at a higher Goertzel frequency of approximately 481 KHz and the discontinuous RF waveform may be at a lower frequency of approximately 433 KHz, resulting in little interference occurring between the sources due to the Goertzel frequency response being divisible by 45 (see Figures 7 and 8) and the concentration of discontinuous energy being at or below its carrier frequency of 433 KHz.

[0048] In embodiments where the first and second RF waveforms are continuous, because continuous waveforms are generally not perfect sine waves, the preselected 433 KHz and 481 KHz unique carrier frequencies also follow a coherent sampling rule, which is used to separate continuous RF sources in conjunction with a Goertzel filter to provide attenuation of constructively or destructively interfering signals from the other source. The bandpass filter provides a signal passband region and lower / upper signal rejection regions. The level of rejection is variable and based on the type of bandpass filter designed. The finite impulse response (FIR) filter provides a sine function (sin x / x) type amplitude vs. frequency response. A computationally efficient Goertzel filter implementation acts like a sampling function, as shown in plots 350 and 360 in Figures 7 and 8.

[0049] Referring to FIG. 9 , a method for controlling the generator 100 is disclosed. The method provides for simultaneous dual operation of the first RF source 202 and the RF second source 302. Initially, each of the first RF source 202 and the second RF source 302 is configured. As described above, each mode is associated with a predetermined RF waveform, which may be monopolar or bipolar, and continuous or discontinuous, based on the desired tissue effect. The generator 100 is configured to operate in a dual monopolar configuration, a dual bipolar mode, or a hybrid monopolar / bipolar configuration, during which each of the first RF source 202 and the RF second source 302 outputs any suitable monopolar or bipolar RF waveform. A user may configure each of the first RF source 202 and the RF second source 302, such as by setting a power level. The first and second RF waveforms are output in response to an activation signal, which may be by any user input through the instrument 20 ′, 20 ″, 30 ′, 30 ″ or the generator 100 .

[0050] During operation, while the mode is active, each of the first RF source 202 and the second RF source 302 continuously outputs first and second RF waveforms, which are separated in the frequency domain and measured by the sensors 216 and 316 to measure tissue impedance and electrical properties of the waveforms.

[0051] The first and second RF waveforms may be delivered simultaneously. During the simultaneous RF waveform transmission, sensors 216 and 316 measure characteristics of the first and second RF waveforms. The RF waveform carrier frequency and coagulation repetition rate may be selected to provide coherent sampling under time-critical power calculation update rates. Controllers 204 and 304 utilize signal processing and / or time-multiplexing techniques to discriminate between the simultaneously activated first and second interrogation waveforms. Controllers 204 and 304 also determine the level of transconductance between the first RF source 202 and the second RF source 302. The carrier frequencies of the first and second RF waveforms are such that they provide coherent sampling under time-critical power calculation update rates, providing effective frequency discrimination and combined transconductance detection. The carrier frequency ratio may be varied between a 45:50 Goertzel ratio and a 49:51 Goertzel ratio to provide different response speeds for tissue contact detection, e.g., to distinguish from open circuits. Time-cascaded Goertzel calculations can also be used to allow for shorter time intervals between power calculations in the algorithm.

[0052] In embodiments, the optimal frequencies of the first and second waveforms may be determined by scanning the frequency response of the first RF source 202 and the second RF source 302 and identifying noise frequencies. After identifying the noise carrier frequencies, quieter frequencies are selected to avoid corruption of the first and second interrogation waveforms, thereby avoiding false detection of tissue contact.

[0053] The sensors 216 and 316, in conjunction with their respective controllers 204 and 304, perform broadband measurements of each of the first and second RF waveforms while simultaneously detecting the transconductance between the first RF source 202 and the second RF source 302. Additionally, during operation, the controllers 204 and 304 also provide overcurrent protection during dual actuation by monitoring the total current through the return electrode pad 26. The controllers 204 and 304 measure the instantaneous current value by squaring it (I) as a variable value during any suitable period of time, which may be from about 15 seconds to about 60 seconds.2 ) to calculate the overcurrent value. The moving value may be calculated every second or at another suitable repetition rate. The overcurrent value is then calculated to be approximately 30 A. 2 The current is compared to an overcurrent threshold, which may be 0.01 V, and if the threshold is exceeded within any 60 second window when monitored at a set rate (e.g., once per second), both RF source 202 and second RF source 302 are shut off.

[0054] Each of the controllers 204 and 304 also utilizes signal processing techniques, i.e., the Goertzel array plot described above, to discriminate between the simultaneously activated first RF source 202 and second RF source 302. The controllers 204 and 304 are also configured to use signal processing discrimination techniques to determine the level of transconductance, if any, between the first RF source 202 and the second RF source 302. After the level of transconductance is determined, the level of transconductance is used as a safety mitigation, i.e., a dose error monitor, during simultaneous monopolar or bipolar RF operation. In particular, upon detection of transconductance by either the controller 204 or 304, each of the controllers 204 and 304 is configured to issue a warning and / or shut down both the first RF source 202 and the second RF source 302 in response to a dose error in transconductance.

[0055] While several embodiments of the present disclosure have been shown in the drawings and / or described herein, the disclosure is not intended to be limited to those embodiments, as the disclosure extends the broadest scope permitted by the art and the specification is intended to be read in the same manner. Accordingly, the above description should not be construed as limiting, but merely as exemplifications of particular embodiments. Those skilled in the art will envision other modifications within the scope of the claims appended hereto.

Claims

1. 1. An electrosurgical generator comprising: a first radio frequency source, a first power supply configured to output a first DC waveform; a first radio frequency inverter coupled to the first power source and configured to generate a unipolar radio frequency waveform from the first DC waveform; and a first controller configured to control the first radio frequency inverter to output the unipolar radio frequency waveform; a first radio frequency source, a second radio frequency source, a second power supply configured to output a second DC waveform; a second radio frequency inverter coupled to the second power source and configured to generate a bipolar radio frequency waveform simultaneously with the unipolar radio frequency waveform; and a second controller configured to control the second radio frequency inverter to output the bipolar radio frequency waveform; a second radio frequency source, wherein the first controller and the second controller are configured to perform frequency domain analysis of the unipolar radio frequency waveform and the bipolar radio frequency waveform, respectively; an electrosurgical generator, wherein each of the first controller and the second controller is further configured to detect a transconductance between the first radio frequency source and the second radio frequency source based on the frequency domain analysis.

2. 10. An electrosurgical generator according to claim 1, further comprising a clock source coupled to the first controller and the second controller and configured to synchronize operation of the first controller and the second controller.

3. An electrosurgical generator according to claim 2, wherein the monopolar radio frequency waveform has a first frequency and the bipolar radio frequency waveform has a second frequency different from the first frequency.

4. 2. The electrosurgical generator of claim 1, wherein each of the first controller and the second controller is further configured to at least one of issue an alert or shut off both the first radio frequency source and the second radio frequency source in response to detecting the transconductance.

5. 10. The electrosurgical generator of claim 1, wherein the first radio frequency source further includes a first active terminal coupled to the first radio frequency inverter and further configured for coupling to a monopolar electrosurgical instrument.

6. 6. The electrosurgical generator of claim 5, wherein the second radio frequency source further includes a second active terminal and a second return terminal coupled to the second radio frequency inverter and further configured for coupling to a bipolar electrosurgical instrument.

7. 7. The electrosurgical generator according to claim 6, wherein the first radio frequency source further includes a first return terminal configured to couple to at least one return electrode pad, the first return terminal being coupled to the first radio frequency inverter and the second radio frequency inverter.

8. 8. An electrosurgical generator according to claim 7, wherein the first radio frequency source further includes a first isolation transformer having a primary winding coupled to the first radio frequency inverter and a secondary winding coupled to the first active terminal and the first return terminal.

9. 9. An electrosurgical generator according to claim 8, wherein the second radio frequency source further includes a second isolation transformer having a primary winding coupled to the second radio frequency inverter and a secondary winding coupled to the second active terminal and the second return terminal.

10. 1. An electrosurgical system comprising: a monopolar electrosurgical device; a bipolar electrosurgical device; 1. An electrosurgical generator comprising: a first radio frequency source, a first power supply configured to output a first DC waveform; a first radio frequency inverter coupled to the first power source and the monopolar electrosurgical instrument, the first radio frequency inverter configured to supply a monopolar radio frequency waveform having a first frequency from the first DC waveform to the monopolar electrosurgical instrument; and a first controller configured to control the first radio frequency inverter; a first radio frequency source, a second radio frequency source, a second power supply configured to output a second DC waveform; a second radio frequency inverter coupled to the second power source and the bipolar electrosurgical instrument, the second radio frequency inverter configured to generate a bipolar radio frequency waveform from the second DC waveform for the bipolar electrosurgical instrument simultaneously with the monopolar radio frequency waveform; and a second controller configured to control the second radio frequency inverter; a second radio frequency source, an electrosurgical generator, wherein the first controller and the second controller are configured to perform frequency domain analysis of the unipolar radio frequency waveform and the bipolar radio frequency waveform, respectively; an electrosurgical system, wherein each of the first controller and the second controller is further configured to detect a transconductance between the first radio frequency source and the second radio frequency source based on the frequency domain analysis;

11. 11. The electrosurgical system of claim 10, wherein the electrosurgical generator further includes a clock source coupled to the first controller and the second controller and configured to synchronize operation of the first controller and the second controller.

12. The electrosurgical system of claim 11 , wherein the monopolar radio frequency waveform has a first frequency and the bipolar radio frequency waveform has a second frequency different from the first frequency.

13. 11. The electrosurgical system of claim 10, wherein each of the first controller and the second controller is further configured to at least one of issue an alert or shut off both the first radio frequency source and the second radio frequency source in response to detecting the transconductance.

14. the first radio frequency source further includes a first active terminal coupled to the first radio frequency inverter and further configured to couple to a monopolar electrosurgical instrument; The electrosurgical system of claim 10 , wherein the second radio frequency source further includes a second active terminal coupled to the second radio frequency inverter and further configured to couple to a bipolar electrosurgical instrument.

15. 15. The electrosurgical system of claim 14, further comprising at least one return electrode pad, the electrosurgical generator further including a first return terminal coupled to the at least one return electrode pad and to the first and second radio frequency inverters.

16. The electrosurgical generator further includes a second return terminal coupled to the second radio frequency inverter and further configured to couple to the bipolar electrosurgical instrument; the first radio frequency source further includes a first isolation transformer having a primary winding coupled to the first radio frequency inverter and a secondary winding coupled to the first active terminal and the first return terminal; 16. The electrosurgical system of claim 15, wherein the second radio frequency source further includes a second isolation transformer having a primary winding coupled to the second radio frequency inverter and a secondary winding coupled to the second active terminal and the second return terminal.

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