Electrosurgical generator control system

Abstract

To provide systems and methods for enhancing surgical outcomes by providing generators having optimal RF output for sealing, fusing and / or cutting tissue or vessels under all dynamic conditions.SOLUTION: A digital closed-loop control system may include: an RF amplifier for generating RF energy; a feedback system for constantly monitoring electrical characteristics, e.g., voltage, current and power, of the supplied RF energy to a connectable electrosurgical instrument; and a microcontroller for processing measurement data from the feedback system and adjusting the output of the RF amplifier to meet a desired regulation target under any varying conditions.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of co-pending U.S. Provisional Patent Application No. 62 / 727,195, filed September 5, 2018, which is hereby expressly incorporated by reference in its entirety for all purposes.

[0002] The present disclosure relates generally to electrosurgical generator systems and methods, and more particularly to an electrosurgical control system configured to dynamically adjust generator output to provide optimal radio frequency (RF) energy for sealing, lysing, and / or cutting tissue or blood vessels. [Background technology]

[0003] Electrosurgical hand devices or instruments are available that use radio frequency (RF) energy to perform certain surgical tasks. An electrosurgical instrument may include one or more electrodes configured to receive electrical energy from an electrosurgical generator. The electrical energy can be used to melt, seal, or cut tissue to which it is applied. Examples of such electrosurgical or surgical instruments include graspers, scissors, tweezers, blades, or needles.

[0004] Electrosurgical instruments typically fall into two categories: monopolar and bipolar. In monopolar instruments, electrical energy is supplied to one or more electrodes on the instrument at a high current density, while a separate return electrode is electrically coupled to the patient and is often designed to minimize the current density. Monopolar electrosurgical instruments may be useful in certain procedures, but may involve the risk of certain types of patient injury, such as electrical burns, that are often attributable at least in part to the function of the return electrode. In bipolar electrosurgical instruments, one or more electrodes are electrically coupled to a source of electrical energy of a first polarity, and one or more other electrodes are electrically coupled to a source of electrical energy of a second polarity opposite the first polarity. Bipolar electrosurgical instruments that operate without a separate return electrode can deliver electrical signals to a concentrated tissue area with reduced risk. Summary of the Invention [Problem to be solved by the invention]

[0005] However, even with the relatively focused surgical effect of bipolar electrosurgical instruments, surgical results are often highly dependent on the surgeon's technique. Enhanced generators have been made to reduce this dependency. [Means for solving the problem]

[0006] According to various embodiments, an electrosurgical system for sealing, lysing, and / or cutting tissue is provided. The electrosurgical system can include an electrosurgical generator and an electrosurgical instrument or device. The electrosurgical generator, according to embodiments of the present invention, can include a digital closed-loop control system that coordinates the delivery of electrosurgical or radio frequency (RF) energy, regulates the RF energy, and in various embodiments, measures and monitors electrical properties, e.g., phase, current, voltage, and power, of the RF energy delivered to a connectable electrosurgical instrument. In various embodiments, the digital control system increases accuracy while ensuring stability in the measurement and regulation of the voltage, current, and power of the RF output. This provides optimal RF output for sealing, lysing, and / or cutting tissue / vessels under dynamic conditions, such as, for example, variable loads, procedure conditions, or operating conditions.

[0007] In accordance with one aspect of the present invention, a digital closed loop control system is provided for use with an electrosurgical generator to deliver electrosurgical RF energy to a surgical site. The digital closed loop control system can include a feedback system that continuously monitors electrical properties of the delivered RF energy and generates a digital RF signal related thereto, and a microcontroller configured with a variable gain factor to adjust and control an RF amplifier that generates the delivered RF energy across multiple RF regulation modes to provide optimal RF output for a surgical procedure under all surgical, operating, or procedural conditions.

[0008] According to a second aspect of the present invention, there is provided a method for dynamically controlling an electrosurgical generator for delivering electrosurgical RF energy to a surgical site through an electrosurgical instrument, the method comprising retrieving desired RF settings or target values ​​for a plurality of RF regulating modes to generate RF energy at the desired RF settings, and measuring an electrical characteristic of the RF output through at least one channel from a feedback system and communicating real and imaginary components of the measurement data to a microcontroller. After receiving the transmitted data, the microcontroller performs power calculations to obtain a magnitude of the measurement data and tissue impedance loading for each of the plurality of RF regulating modes.

[0009] The method further includes generating an error signal over a plurality of RF tuning modes and selecting one tuning mode based on the calculated error value; calculating a variable gain coefficient for each of the plurality of tuning modes using a special algorithm and selecting one variable gain based on the calculated error value; determining power control signals for Buck and H-bridge circuits of an RF amplifier of the electrosurgical generator; and controlling the amount of RF power of the electrosurgical generator in response to the power control signals to maintain a desired output value of the generator.

[0010] According to a third aspect of the present invention, there is provided an electrosurgical system for performing a surgical procedure. The electrosurgical system may include an electrosurgical generator adapted to deliver RF energy to a surgical site and an electrosurgical instrument connected to the electrosurgical generator. The electrosurgical instrument has at least one active electrode adapted to apply electrosurgical RF energy to tissue at the surgical site. The electrosurgical generator may include a primary FPGA (fully programmable gate array) configured to cause the steps of generating an error signal over a plurality of RF tuning modes to select a tuning mode, computing variable gain factors for the plurality of tuning modes to select a variable gain factor, integrating the selected error signal to generate an integral signal and multiplying the generated integral signal by the selected variable gain factor, and using the predicted output voltage and the generated integral signal, respectively, to drive duty cycles for Buck and H-bridge circuits of an RF amplifier.

[0011] According to a fourth aspect of the present invention, there is provided an electrosurgical generator comprising an RF amplifier for delivering RF energy, a feedback system adapted to continuously monitor an electrical property of the delivered RF energy and generate a digital RF signal related thereto, and a primary microcontroller programmed to compute variable gain factors and preload functions that enable dynamic control of the delivered RF energy across multiple RF regulation modes and multiple RF resolution settings under all surgical, operating and procedural conditions.

[0012] According to a fifth aspect of the present invention, there is provided a method for impedance assessment of an electrosurgical instrument connected to an electrosurgical generator prior to performing a surgical procedure, the method comprising the steps of initiating a low voltage or passive mode upon power-up of the connected electrosurgical instrument, generating an RF power limited to a value determined by the low voltage mode, measuring an electrical characteristic of the RF power and digitally transmitting the measurement data to a microcontroller of the electrosurgical generator, calculating other electrical characteristics of the RF power based on the received measurement data and transmitting the calculation results to a primary processor in the microcontroller, and determining whether the calculation results satisfy certain criteria established by a device script of the connected electrosurgical instrument.

[0013] According to a sixth aspect of the present invention there is provided an electrosurgical generator including an RF amplifier for supplying RF energy and a microcontroller configured to dynamically control the supplied RF energy across at least one regulation mode from a plurality of RF regulation modes and a plurality of RF resolution settings.

[0014] According to a seventh aspect of the present invention there is provided an electrosurgical generator including an RF amplifier for delivering RF energy and a microcontroller configured to determine at least one of a variable gain factor and a preload function for dynamically controlling the delivered RF energy.

[0015] Many of the attendant features of this invention will become better understood by reference to the foregoing and following description and will be more readily appreciated when considered in connection with the accompanying drawings, in which:

[0016] The present disclosure will now be described in conjunction with the accompanying drawings. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1 is a perspective view of an electrosurgical generator according to various embodiments of the present invention. [Diagram 2] 1 is a perspective view of an electrosurgical hand device according to various embodiments of the present invention. [Diagram 3] 1 is a perspective view of an alternative embodiment of an electrosurgical hand device in accordance with various embodiments of the present invention. [Figure 4] FIG. 1 is a block diagram of an electrosurgical generator in accordance with various embodiments of the present invention. [Diagram 5] FIG. 2 illustrates a block diagram of an embodiment of a feedback system within the control system of an electrosurgical generator in greater detail. [Figure 6] FIG. 2 illustrates in more detail a block diagram of an embodiment of a primary microcontroller within the control system of the electrosurgical generator. [Figure 7] FIG. 2 is a schematic diagram of the operating modes and functional blocks of the various circuits and systems within the primary microcontroller of the electrosurgical control system of the present invention. [Figure 8] FIG. 2 is a schematic diagram of the operating modes and functional blocks of the various circuits and systems within the primary microcontroller of the electrosurgical control system of the present invention. [Figure 9] FIG. 1 is a block diagram of an embodiment of a control system for an electrosurgical generator operating in a passive regulation mode. [Figure 10] 4 is a flow diagram of an embodiment of a passive regulation mode operation or process of an electrosurgical generator in accordance with an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] In the accompanying drawings, similar components and / or features may have the same reference label. When a reference label is used in this specification, the description is applicable to any of the similar components having the same reference label.

[0019] The following description provides only preferred exemplary embodiments and is not intended to limit the scope, applicability, or configuration of the present disclosure. Rather, the following description of preferred exemplary embodiments will provide those skilled in the art with an enabling description for implementing the preferred exemplary embodiments of the present disclosure. It should be understood that various changes can be made in the function and arrangement of elements without departing from the spirit and scope of the present invention as recited in the appended claims.

[0020] The present disclosure relates generally to electrosurgical systems and, more particularly, to a new generation of electrosurgical generators capable of adjusting RF output voltage, current, and power under dynamically changing impedance loads and control conditions.

[0021] Embodiments of the present invention relate to systems and methods for enhancing surgical outcomes by providing a generator with optimal RF output to seal, lyse, and / or cut tissue or vessels under all dynamic conditions, such as, for example, changing tissue impedance loading due to electrosurgical actuation or tissue impacts, and all operating conditions and commands determined by the surgeon, surgical procedure, and / or device script. This is accomplished by implementing a digital closed-loop control system that regulates the voltage, current, and power of the RF output. The digital closed-loop control system can include an RF amplifier that generates the RF energy, a feedback system that continuously measures and monitors the electrical characteristics, e.g., voltage, current, and power, of the RF energy delivered to a connectable electrosurgical instrument, and a microcontroller for processing measurement data from the feedback system and adjusting the output of the RF amplifier to meet desired regulation targets under all varying conditions.

[0022] In accordance with embodiments of the present invention, a feedback system measures the analog RF output through at least one channel and digitizes the measurements. In various embodiments, the feedback system simultaneously collects voltage and current measurements from the RF amplifier and digitizes the measurements through an analog-to-digital converter (ADC). The feedback system is configured to process the digitized values ​​to derive real and imaginary components of the voltage and current RF output and provide the real and imaginary components to the primary microcontroller.

[0023] In accordance with embodiments of the present invention, the primary microcontroller calculates individual error values ​​for voltage, current, and power and selects a regulation mode based on the individual error values. The primary microcontroller in various embodiments uses a specialized algorithm to calculate a specific variable gain factor for each regulation mode that enables an electrosurgical system in accordance with embodiments of the present invention to have, for example, a deterministically damped step response under any variable condition, e.g., surgical, operational, or procedural condition.

[0024] The electrosurgical system and method according to the present invention are described in detail below in sections, each of which separately describes an electrosurgical generator, an electrosurgical instrument, and a digital closed-loop control system and method used in accordance with an embodiment of the present invention to provide optimal RF power under any dynamically changing external conditions.

[0025] Various embodiments provide an electrosurgical generator that controls the delivery of electrosurgical or radio frequency (RF) energy, regulates the RF energy, and in various embodiments measures and monitors electrical properties, such as the phase, current, voltage, and power, of the RF energy delivered to a connectable electrosurgical instrument to ensure optimal sealing, lysis, and / or cutting of tissue or blood vessels. In various embodiments, the generator includes a feedback system that determines such electrical properties and adjusts and controls an RF amplifier that generates the required RF energy through a microcontroller to provide optimal RF power to seal, lyse, and / or cut tissue or blood vessels under dynamic conditions, such as changing loads, procedure conditions, or operating conditions.

[0026] 1-2, an exemplary embodiment of an electrosurgical system for use in a surgical procedure is shown. As shown in these figures, the electrosurgical system can include an electrosurgical generator 10 and a removably connectable electrosurgical tool or instrument 20. The electrosurgical hand device or electrosurgical instrument 20 can be electrically coupled to the generator 10 through a cabled connection with a device key or connector 21 that extends from the instrument 20 to a device connector or access port 12 on the generator 10. The electrosurgical instrument 20 can include audio, tactile, and / or visual indicators to notify a user of a particular or defined status of the instrument 20, such as, for example, the start and / or end of a lytic procedure. In some embodiments, a manual controller, such as a hand or foot switch, can be connectable to the generator 10 and / or the instrument 20 to allow for defined, selective control of the instrument, such as to initiate a lytic procedure.

[0027] According to various embodiments, the electrosurgical generator 10 includes a display 14 that can indicate, among other information, the status of the electrosurgical system, including the status or operation of one or more electrosurgical instruments and / or accessories, connectors or connections thereto, the generator, and error indicators. The electrosurgical generator 10 according to various embodiments of the present invention can include a user interface, such as, for example, a number of buttons 16. The number of buttons 16 allows for user interaction with the electrosurgical generator 10. This user interaction can include, for example, requesting an increase or decrease in electrical energy delivered to one or more instruments 20 coupled to the electrosurgical generator 10. In various embodiments, the generator 10 further includes a user-accessible power-on switch or button 18 that, when activated, powers the generator 10 and activates or begins a self-verification system test of the generator. In other embodiments, the display 14 can be a touch screen display, such that data display and user interface functionality are integrated.

[0028] In various embodiments, the electrosurgical generator 10 of the present invention is configured to output radio frequency (RF) energy through one or more electrodes through a connectable electrosurgical instrument or hand device 20 to seal, lyse, and / or cut tissue or blood vessels. The electrosurgical generator 10 is configured to generate RF energy up to 300V, 8A, and 375VA, in accordance with embodiments of the present invention, and is also configured to determine the phase angle or difference between the RF output voltage and the generator's RF output current during activation or delivery of RF energy. In this manner, the electrosurgical generator 10 adjusts the voltage, current, and / or power and monitors the RF energy output (e.g., voltage, current, power, and / or phase). In one embodiment, the generator 10 can stop, terminate, or otherwise interrupt the RF energy output under defined conditions. By way of example, these defined conditions may be any of the following conditions: when a device switch is deasserted (e.g., melt button release), when a time value is satisfied, and / or when the active phase angle and / or active phase change is greater than or equal to a phase and / or phase change stop indicating the end of a procedure, such as melting or cutting of tissue.

[0029] The electrosurgical instrument 20, in accordance with an embodiment of the present invention, can include an elongated shaft 26 having a proximal end coupled to or from which the actuator 24 extends, and a distal end coupled to or from which the jaws 22 extend. A longitudinal axis extends from the proximal end to the distal end of the elongated shaft 26. In one embodiment, the actuator 24 can include a movable handle 23 pivotally coupled to a fixed handle or housing 28. The movable handle 23 is coupled to the fixed handle or housing 28 through a central or primary floating pivot. In actuation, the movable handle 23 is manipulated by a user, e.g., a surgeon, to actuate the jaws 22 at the distal end of the elongated shaft 26 such that the jaws 22 are selectively opened and closed. When tissue or blood vessels are grasped between the jaws 22, a switch or button 29 is activated by the surgeon to seal, dissolve, and / or cut the tissue / vessel between the jaws 22. When the button 29 is activated, the associated circuitry or contacts are connected to connect appropriate electrodes on the jaws to connections associated with the generator 10 for supplying RF energy to tissue grasped between the jaws 22 or otherwise in contact with one or more electrodes of the jaws.

[0030] In various embodiments, the electrosurgical instrument 20 further includes a mechanical or electrical cutting blade that can be coupled to a blade actuator, such as a blade lever or trigger 25 on a stationary handle or housing 28. The cutting blade is actuated by the blade trigger 25 to divide or cut tissue between the jaws 22. In various embodiments, a blade slider is connected to the blade trigger 25, with a protrusion extending from a proximal portion of the blade slider into an opening in one end of the blade trigger to connect the components together. The other end of the blade trigger is exposed and accessible by the user, and the blade trigger 25 is pivotable about a trigger pivot at or near the midpoint of the blade trigger. Thus, with the blade trigger 25 pulled or rotated proximally by the user, the end of the blade trigger connected to the blade slider slides or moves distally down the blade slider. Integral with or attached to the distal end of the blade slider is a cutting blade, knife, or cutting edge or face. Thus, tissue grasped between the jaws 22 is severed as the blade slider translates longitudinally through the blade channel of the jaws. In one embodiment, the cutting edge or face is beveled to facilitate severing of tissue between the jaws 22. In various embodiments, the cutting blade is a curved blade, hook, knife, or other cutting element sized and configured to cut tissue between the jaws 22.

[0031] According to various embodiments, the elongated shaft 26 includes an actuation tube or rod that couples the jaws 22 with the actuator. In one embodiment, the actuator includes a rotating shaft assembly including a rotation knob 27 disposed on an outer cover tube of the elongated shaft 26. The rotation knob 27 allows the surgeon to rotate the shaft of the device while gripping the actuator. In various embodiments, the elongated shaft 26 is rotatable 360°, while in other embodiments, the rotation of the elongated shaft 26 is limited to 180°, i.e., 90° clockwise and 90° counterclockwise. FIG. 3 illustrates an alternative embodiment of an electrosurgical hand device 20′ connectable to the electrosurgical generator 10. The electrosurgical hand device 20′ is similar but includes different features and has a different surgical application than the electrosurgical hand device 20.

[0032] Referring now to FIG. 4, a block diagram of an electrosurgical generator 10 is shown in accordance with an embodiment of the present invention. As shown in this figure, the electrosurgical generator 10 can include a power supply module, e.g., a power-on module 31, e.g., an AC mains input, coupled to two DC 48V power supplies 32, 33. The power supply module converts AC voltage from the AC mains input to DC voltage and provides power through a housekeeping power supply 34 to various circuits of the generator 10, and in particular to an RF amplifier 40, which generates or outputs RF energy. In one embodiment, the RF amplifier 40 can include a Buck and H-bridge circuit that converts a DC voltage input to an RF output and in another embodiment, a variable amplitude 350 kHz sine wave. The DC voltage input is a DC 96V input generated by two DC 48V power supplies 32, 33 coupled in series. One of the DC 48V power supplies 32, 33 is configured to generate a low voltage rail and, in particular, to provide a standby voltage for powering up the generator 10.

[0033] In accordance with an embodiment of the present invention, the electrosurgical generator 10 further includes a control system or digital integrating servo control system 100 that regulates and controls the RF output. As shown in FIG. 4, the control system 100 can include an RF amplifier 40, a primary microcontroller 50, and a feedback system 60. The RF output and, in various embodiments, the amplitude of the RF waveform output is controlled and regulated by an electrosurgical control system 100 built into or integrated within the electrosurgical generator 10. The control system 100 varies between regulating voltage, current, or power of the RF output generated by the RF amplifier 40. In various embodiments, the feedback system 60 measures the RF output and digitally provides real and imaginary components of the RF output to the primary microcontroller 50 after processing the measurement data. The primary microcontroller 50 processes the data received from the feedback system 60 and regulates the output of the RF amplifier 40 to meet the desired regulation target, in accordance with an embodiment of the present invention. In various embodiments, the feedback system 60 is comprised of an analog input, digital processing, and digital output.

[0034] In various embodiments, the electrosurgical generator 10 records all RF output data on an internal memory device, such as a secure digital (SD) memory card or a non-volatile memory card. The memory device is configured to be read through an interface port 35, such as a universal serial bus (USB) port, on the electrosurgical generator 10. In various embodiments, the generator 10 is configured to copy the data from the internal memory device to a connectable portable storage, such as a USB flash drive, through the generator's interface port.

[0035] In accordance with various embodiments of the present invention, electrosurgical generator 10 is further configured to provide RF power in three resolution settings or modes: low voltage, normal or medium voltage, and high voltage. In various embodiments, a device script stored and located on a connectable electrosurgical hand device, e.g., instrument 20 and / or a connector coupled thereto, e.g., device key 21, is used to determine or set the RF power or voltage mode.

[0036] 1 and 4 and according to various embodiments, the electrosurgical generator 10 is configured to alert the surgeon when the vessel has reached a complete procedure state (e.g., a complete seal state) or when an error or fault condition occurs. The electrosurgical generator 10, in various embodiments, can include visual, tactile, and / or audible outputs that provide such alerts or other indicators or information to the surgeon as dictated by the surgical procedure, the device script, or health or operational information regarding the device 20 and / or the generator 10. In one embodiment, the generator 10 through a front panel interface 38 alerts the surgeon through an LCD display 14 integrated into the generator's front panel, and in various embodiments provides certain audible alarms or informational tones through a speaker 36 further integrated into the generator's front panel. The generator 10, in various embodiments, can include a front panel overlay 39 that provides a user interface or access, including push buttons for navigation to allow user access to system settings such as volume or display brightness. The front panel overlay 39 can include a system power button or connection. In various embodiments, a fan system 37 is provided to aid in heat dissipation. Additionally, as shown in Figure 4, signal or sig represents connections including, for example, digital signals used to communicate information across the system and / or printed circuit boards, power represents connections including, for example, voltage rails used to power the system and / or printed circuit boards, and RF represents connections including, for example, high voltage high current RF energy used to seal, melt or cut tissue or blood vessels.

[0037] FIG. 5 illustrates in more detail a block diagram of an embodiment of a feedback system 60 within the control system 100 of the electrosurgical generator 10. As further described above and also shown in FIG. 5, the control system 100 can include an RF amplifier 40, a primary microcontroller 50, and a feedback system 60. According to various embodiments of the present invention, the RF amplifier 40 generates an RF output and the feedback system 60 measures various electrical properties of the RF signal output from the RF amplifier 40. According to embodiments of the present invention, the verification system 60 can include a primary channel 601, a redundant channel 602, and a verification channel 603. The primary channel 601 and the redundant channel 602 can include separate but identical components in various embodiments. Additionally, the primary channel 601 and the redundant channel 602 are along separate but identical electrical paths and, in one embodiment, are both connected to the RF amplifier 40 and the RF output.

[0038] Similarly, the components of the verification channel 603 are separate but similar to the primary channel 601 and the redundant channel 602. In one embodiment, the verification channel 603 can include the same components as the primary channel 601 and the redundant channel 602, but the components in the verification channel 603 have higher ratings, e.g., higher resolution or lower drift, and are often more expensive. In another embodiment, the verification channel 603 can include the same components as the primary channel 601 and the redundant channel 602. The verification channel 603 is also connected along separate but the same electrical paths as the primary channel 601 and the redundant channel 602, and in one embodiment to the RF amplifier 40 and the RF output. In various embodiments, the feedback system 60 measures the analog RF output and digitizes the measurements. The feedback system 60 is configured to measure and digitize the RF output through at least one channel, e.g., the primary channel 601. In this embodiment, the feedback system 60 through the primary channel 601 measures the analog RF output through the front-end circuitry 611.

[0039] As shown in FIG. 5, the front-end circuit 611 may include a shunt resistor 615 coupled to the preamplifier 613 to measure the current of the RF output. In various embodiments, the front-end circuit 611 further includes a voltage divider 614 coupled to the preamplifier 612 to measure the voltage of the RF output. The outputs of the preamplifiers 612, 613 are provided to an analog-to-digital converter (ADC) 616, which digitizes the resulting current and voltage measurements. The digitized values ​​are further processed to derive real and imaginary components of the voltage and current RF output. In various embodiments, the digitized values ​​from the ADC 616 are provided to a fully programmable gate array (FPGA) 617 of the feedback system 60. The FPGA 617 is configured to process the digitized voltage and current measurements to generate real and imaginary components of the voltage and current RF output using separate Fourier transforms. The digital real and imaginary components are then provided to the primary microcontroller 50 and, in one embodiment, through a serial communication protocol.

[0040] Referring to FIG. 6, a schematic diagram of an embodiment of the control system 100 is shown illustrating a block diagram of an embodiment of the primary microcontroller 50 of the electrosurgical generator 10 in more detail. As shown in this figure, the primary microcontroller 50 can include a primary ARM (advanced reduced instruction set machine) processor 501 and a primary FPGA (fully programmable gate array) 510. The primary ARM processor 501 is configured to establish desired output values, such as voltage, current, and / or power, for example, as setpoints 502. In various embodiments, the desired output values ​​can be provided by a device script. According to various embodiments, the primary FPGA 510 of the primary microcontroller 50 receives digital real and imaginary components of the voltage and current measurements to calculate the magnitudes of the RF output voltage, current, and power. The magnitudes of the RF output voltage, current, and power are calculated using a VCW (voltage, current, power) calculator 511, as shown in FIG. 6. Individual error values ​​of the voltage, current, and power are also calculated by an error processor 512. In one embodiment, the error values ​​are calculated by subtracting the desired voltage, current, and power settings from the measured magnitudes.

[0041] The error processor 512 calculates the relative error between the main channel measurements and the setpoint 502 and determines or selects a regulation mode based on the error value. Thus, the error processor 512 determines which of the three regulation modes, e.g., voltage, current, and power, needs to be augmented or activated by the electrosurgical generator 10. In various embodiments, the calculated error value of the selected mode is integrated by an integrator 513 to generate an error signal that is directly proportional to the output of the RF amplifier 40 and is used to correct the output of the RF amplifier 40.

[0042] In accordance with embodiments of the present invention, the calculated error values ​​can be used to determine a variable gain factor for each regulation mode (e.g., voltage, current, and power) of the generator 10. The variable gain is configured to use a different predefined set of calculations or algorithms based on the selected regulation mode. As shown in FIG. 6, a VG (variable gain) module 515 is used to calculate a variable gain value for each regulation mode (e.g., voltage, current, and power). The variable gain factor can be calculated in accordance with embodiments of the present invention as a function of the voltage, current, and power set points, the calculated external impedance load or tissue load, the Buck voltage value, and the value of the error integral, or any combination thereof. Thus, the variable gain in various embodiments provides a deterministic step response for all set points and impedance load conditions or any changes thereto. In other words, the variable gain in accordance with embodiments of the present invention allows the electrosurgical generator 10 to be deterministically attenuated under all changing conditions, such as, for example, surgical, operating, and procedural conditions. In various embodiments, the variable gain factor can be recalculated on a predefined schedule or timing, such as, for example, every cycle of the RF power.

[0043] According to various embodiments and with further reference to FIG. 6, the primary microcontroller 50 is configured to predict the required output voltage of the generator 10 in order to regulate the RF amplifier 40. In various embodiments, the primary FPGA 510 of the primary microcontroller 50 can predict the required voltage of the generator 10 using the calculated impedance load and the voltage, current and power settings. The estimate is then used by a Buck duty cycle calculator 514 to calculate the duty cycle value of the pulse width modulator (PWM) of the integrating Buck circuit of the RF amplifier 40. On the other hand, the product of the error integral and the calculated variable gain factor (K i *∫e(t)) can be used to derive a duty cycle value for the H-bridge circuit of the RF amplifier 40. Thus, the control system 100 according to embodiments of the present invention can provide dynamic adjustment of the variable or fluctuating RF output of the generator 10. In various embodiments, the electrosurgical generator 10 can be switched between a voltage regulation mode, a current regulation mode, and a power regulation mode. In such embodiments, the control system 100 is configured to perform a preload calculation or function to provide a gradual and uninterrupted transition in the RF output, as will be described in more detail below.

[0044] The control system 100, in accordance with an embodiment of the present invention, provides for the adjustment of RF power output under dynamically changing impedance loads due to, for example, electrosurgery or electrosurgical tissue effects and control conditions, e.g., device script or user actuation. The control system 100 configured with variable gain rather than fixed gain allows the control system 100 to adjust for different load impedances and output voltages and thus is not limited to being optimized to obtain, for example, the lowest load impedance and / or highest output voltage. The control system 100 is also configured to handle the system being overdamped as impedance increases, which can cause non-optimal phase margins and dynamic or unpredictable behavior, and the ability of the control system 100 to track or follow dynamic commands, e.g., device script actuations, can be affected. The generator control system 100 ensures that tissue electrosurgical effects, such as sealing, lysing, or cutting, are optimized through dynamically changing tissue impedance conditions and actuation conditions and the deterministic response of the control system to commands determined by the surgeon, surgical procedure, and / or device script.

[0045] As further described above, feedback system 60 according to an embodiment of the present invention may include a second channel, e.g., redundant channel 602, which is substantially identical to primary channel 601. Measurements and derived calculations from redundant channel 602 are continuously compared to those of primary channel 601 to verify operation of primary channel 601. Thus, if primary channel 601 and redundant channel 602 have different measurements or calculations, a generator error is recognized and delivery of RF energy is discontinued.

[0046] According to various embodiments, the feedback system 60 can include various other systems and circuits, such as a sampler or other calculator (not shown), for sampling and / or other calculations as required by the electrosurgical control system 100 of the present invention. In various embodiments, the feedback system 60 measures the analog voltage and current of the RF output of the RF amplifier 40, and in various embodiments, the feedback system 60 takes a predetermined number of samples per voltage and current measurement per RF output cycle operating at 350 KHz. In some embodiments, the feedback system 60 can utilize demodulation and conversion to obtain zero frequency components or remove unwanted higher order frequency harmonics from the measured voltage and current values. As further described above, the feedback system 60 continuously communicates or transmits, for example, real and imaginary values ​​of the measured voltage and current to the primary microcontroller 50.

[0047] In the following, the operating modes and functional blocks of the various circuits and systems within the primary FPGA 510 are described in detail in sections, with the VCW calculator 511, error processor 512, integrator 513, Buck duty cycle calculator 514, and VG module 515 being described individually.

[0048] 7-8 are schematic diagrams of operational modes and functional blocks of various circuits and systems within the primary microcontroller 50 of the electrosurgical control system 100 of the present invention. In accordance with an embodiment of the present invention, the primary FPGA 510 receives real and imaginary components or values ​​of the measured voltages and currents from the feedback system 60 and uses these components to calculate their respective root mean square (RMS) magnitudes using a VCW calculator 511. The VCW calculator 511 may further include a load calculator 560 (best shown in FIG. 7), which uses the feedback system voltage and current measurements to calculate the impedance load or tissue load. In some embodiments, filtered voltage and current measurements are used to calculate the impedance load.

[0049] The primary FPGA 510 is further configured to perform error processing using an error processor 512. As shown in FIG. 7, the error processor 512 may include an error calculator 514 and an error selector 516. The error processor 512 calculates the error between the main channel measurements from the feedback system 60 and the set value to determine which adjustment mode is required to correct the RF output power. This is accomplished by calculating the relative error between the set value and the measurements, and in various embodiments, this error calculation is performed simultaneously for voltage, current, and power by the error calculator 514. The error processor 512 utilizes the error selector 516 to determine which adjustment mode needs to be implemented by the electrosurgical generator 10. Thus, the error selector 516 will select the adjustment mode based on the most positive calculated error value. Thus, the error having the most positive value will determine which adjustment mode must be used by the electrosurgical generator 10. The primary FPGA 510 also, in various embodiments, normalizes the magnitude of the calculation to the maximum count value before converting it to a floating point value.

[0050] The integrator 513 constantly integrates the error at the most positive value, e.g., in the selected regulation mode. In operation, the RF amplifier 40 may be switching between different RF regulation modes, e.g., voltage regulation mode, current regulation mode, and power regulation mode, so the integrator 513 needs to be preloaded with another value that allows the RF output to remain constant while transitioning between the various regulation modes. For this purpose, a preload function or preload calculator 532 is implemented in the primary FPGA 510 (best shown in FIG. 7). The preload function or preload calculator 532 is configured to calculate the variable gain for the mode the RF amplifier is transitioning to and preload this value to the integrator 513 using a relay or switch 533 (best shown in FIG. 7). The preload function is calculated using counts and calculated tissue impedance loads of the Buck and H-bridge circuits of the RF amplifier, thereby ensuring seamless transitions between the various regulation modes.

[0051] The primary FPGA 510 provides a variable integral control system that determines the output of the Buck and H-bridge (best shown in FIG. 8) controls of the RF amplifier 40. In various embodiments, the variables used by the variable integral control system can include, for example, an impedance load calculation or tissue load calculation, voltage, current, and power set points, and the calculated RMS magnitudes of the voltage, current, and power. The load calculator 560 can use filtered voltage and current measurements to calculate the impedance or tissue load. In some embodiments, the variable integral control system only adjusts the voltage directly; to adjust the current or power, a corresponding voltage value must be calculated. In various embodiments, the Buck duty cycle calculator 514 (best shown in FIG. 7) predicts where the output voltage of the RF amplifier 40 needs to be using the calculated impedance load and the voltage, current, and power set points. The predicted voltage value is then used to generate the count for the integral Buck PWM circuit of the RF amplifier 40. The output voltage of the Buck PWM circuit of the RF amplifier 40 sets the main voltage rails of the integral H-bridge PWM circuit of the RF amplifier 40.

[0052] According to an embodiment of the present invention, the primary FPGA 510 uses the predictions enumerated by the variable integral control system to set the count of the Buck PWM circuit of the RF amplifier 40, and in various embodiments, responds quickly to reach roughly the desired output value, e.g., near the predicted voltage value. In various embodiments, the primary FPGA 510 drives PWM signals to the Buck and H-bridge (best shown in FIG. 8) configurations or circuits of the RF amplifier 40. In various embodiments, the determination of the PWM signal of the H-bridge configuration is used to fine-tune the output RF to the desired output. The duty cycle of the H-bridge circuit of the RF amplifier 40 is determined by the multiplication of the calculated variable gain coefficient and the integral signal or error integral for the selected mode (best shown in FIG. 8). As can be seen in FIG. 8, the VG (variable gain) module 515 can include a variable gain calculator 534 and a multiport selector 535. The variable gain calculator 534 calculates the variable gain for each regulation mode (e.g., voltage, current, and power) and selects the appropriate variable gain coefficient based on the same criteria used by the error processor 512, e.g., the error with the most positive value. The calculated variable gain can be defined as a function of the calculated impedance load, the voltage, current, and power set points, the Buck voltage value, and the integral or accumulated error. In various embodiments, the primary FPGA 510 converts the respective numerical duty cycle counts to drive PWM signals that control the Buck and H-bridge configurations.

[0053] In various embodiments, the primary ARM processor 501 validates the setpoints to ensure that the voltage, current, and power setpoints meet the thresholds for the mode in which the electrosurgical generator 10 is operating. According to various embodiments, calibration values ​​are stored in the EEPROM of the feedback system 60. These values ​​are specific predefined coefficients used to eliminate discrepancies or tolerances on the feedback system 60. In various embodiments, all three channels 601, 602, and 603 have voltage, current, and power calibration values ​​for normal or medium, high, and low voltage modes, except for the verification channel 603, which does not have a low voltage mode. The mode therefore determines the correct voltage, current, and power calibration coefficients used in the servo calculations. This is also based on the regulation mode in which the generator is operating.

[0054] In various embodiments, the error processor 512 further includes one or more constants such as a normalization factor, an error factor, and / or a point position (useful for floating point conversion). In various embodiments, the primary microcontroller 50 calculates the error between the main channel measurement and the set point and determines which adjustment mode should be used to correct the servo, e.g., output of RF energy. In various embodiments, the primary microcontroller 50 obtains an absolute measurement using the calculated measurement and the error processor coefficients. Along with this absolute measurement, the primary microcontroller 50 obtains a calibrated absolute measurement using the calibration coefficients and obtains a relative estimate with the normalization factor. The primary microcontroller determines the relative error by comparing the difference between the relative measurement and estimate and the set point established by the primary processor 501.

[0055] According to various embodiments, the primary microcontroller 50 using a multiplexer provides respective values ​​of the relative errors calculated for voltage, current and power, and a comparison is performed between the calculated errors to output the maximum or most positive error to determine the regulation mode for the generator.

[0056] Using the selected regulation mode and its corresponding voltage value, the primary microcontroller 50 calculates the voltage output required for optimal operation of the generator 10. In various embodiments, when the control system 100 adjusts the output voltage, the current and power output targets are converted to respective voltages at the calculated load. The regulation mode then determines which calculated output is to be used by the control system 100.

[0057] In various embodiments, the control system 100 operates as a variable integral control loop. The variables are voltage, current and power measurements, set points and load calculations, and the system operates at a predefined frequency, e.g., 350 kHz, and can switch between the integral control loops. The electrosurgical generator 10 thus provides a control system for the voltage, current and power drive sources, and thus provides generator integral control loops for current, voltage and power. In addition, since switching between integral control loops occurs when regulation modes are changed, the control system 100 embeds a preload function for each mode, i.e., voltage, current and power, to ensure a smooth transition between regulation modes.

[0058] According to various embodiments, the feed system 60 can include three channels: a primary channel 601, a redundant channel 602, and a verification channel 603. The primary channel 601 and the redundant channel 602 are nearly identical, while the verification channel 603 has similar functionality to the primary channel 601 and the redundant channel 602, but with higher resolution, lower tolerance, and lower drift components.

[0059] According to various embodiments, each of the channels 601, 602, and 603 of the feedback system 60 can include an analog section that attenuates and amplifies the RF voltage / current measurement signal. In various embodiments, the RF voltage signal is attenuated by a network of resistor dividers before being differentially amplified to drive the ADCs (616, 626, 636). In various embodiments, all three channels 601, 602, and 603 have different sets of amplifier gain resistors to measure different voltage modes, i.e., normal voltage mode and high voltage mode. In various embodiments, the normal voltage mode includes voltages less than or equal to 166V, and in the high voltage mode, the voltage is less than or equal to 322V. According to various embodiments, the primary channel 601 and the redundant channel 602 have alternative sets of resistor configurations to more accurately measure lower voltages, which in various embodiments are less than or equal to 10V. The resistive divider of the verification channel includes resistors with much lower tolerance and lower drift than the primary channel 601 and the redundant channel 602 in various embodiments.

[0060] According to various embodiments, an RF current measurement signal is taken from each channel of the verification system 60 across a shunt resistor (615, 625, 635). All shunt resistors 615, 625, and 635 are in series in various embodiments so that each channel measures the same current signal. The primary channel 601 and redundant channel 602 have alternate sets of shunt resistors in various embodiments to more accurately measure lower currents, e.g., currents less than or equal to 100 mA. The verification channel 603 has shunt resistors that are lower tolerance and lower drift than the primary channel 601 and redundant channel 602.

[0061] According to various embodiments, the measurement signal after the amplifiers (612, 613, 622, 623, 632, 633) passes through a filter for ADC input filtering. The verification channel 603 has filter components with much lower tolerance and drift than the primary channel 601 and the redundant channel 602. In various embodiments, the verification channel filter has a steeper roll-off and therefore a steeper attenuation of higher frequencies.

[0062] According to various embodiments, the data conversion components are independent between each of the three channels 601, 602, and 603. The ADCs (616, 626, 636) convert the analog voltage and current measurement signals into discrete samples that are processed by the respective channel's FPGAs (617, 627, 637). The verification channel's ADC 636 has higher resolution, e.g., more bits, than the primary channel 601 and the redundant channel 602, and has lower drift than the primary channel 601 and the redundant channel 602. In various embodiments, the verification channel's ADC 636 also has a locally generated reference voltage to accurately set the input range of the ADC 636.

[0063] In various embodiments, the feedback system's FPGA (617, 627, 637) performs I / Q demodulation on the discrete voltage and current measurement samples to obtain real and imaginary samples. The measurements are passed through a Discrete Fourier Transform to obtain real and imaginary valued DC components for the voltage and current measurements. In various embodiments, the verification channel 603 includes locally generated digital voltage rails that precisely power the FPGA's input / output pins.

[0064] According to various embodiments, each channel of the feedback system 60 independently communicates its data to the primary microcontroller 50 through an independent communication connection. In various embodiments, the verification channel data is used by the self-verification system or process only at a predetermined time or schedule, for example, upon start-up of the generator 10. During the self-verification process, the verification channel data is compared to the primary and redundant channel data to verify the accuracy and functionality of the primary channel 601 and redundant channel 602. In various embodiments, throughout RF-related operation, the primary channel data is the only set of data used by the control system 100, and the redundant channel data is continually compared to the primary channel data to ensure that the primary channel 601 is operating within predetermined parameters and / or tolerances.

[0065] In accordance with an embodiment of the present invention, the servo control system 100 of the electrosurgical generator 10 may include an RF amplifier 40, a feedback system 60, and a primary microcontroller 50. The feedback system 60 generates a closed loop system path between the RF amplifier 40 and the primary microcontroller 50. The feedback system 60, in various embodiments, measures the voltage and current of the applied RF signal and calculates real and imaginary components of the measurements in one or more channels 601, 602, and 603. In one embodiment, only one channel, the primary channel 601, is provided in the feedback system 60. In another embodiment, two channels, the primary channel 601 and the redundant channel 602, are provided. In yet another embodiment, three channels, the primary channel 601, the redundant channel 602, and the verification channel 603, are provided. The calculated components in the one or more channels are transmitted or communicated to the primary microcontroller 50.

[0066] According to various embodiments, the primary channel 601 and the redundant channel 602 are copies of each other and are used by the primary microcontroller 50 to monitor the voltage and current of the RF output during operation of the electrosurgical generator 10. The verification channel 603 is similar to the other two channels 601 and 602, but includes, for example, more drift resistant components and / or uses an ADC with higher resolution. This channel, in various embodiments, is used for generator start-up and generator self-verification is performed. The feedback system 60, in various embodiments, simultaneously collects voltage and current measurements from the RF amplifier 40. In various embodiments, the generated RF signal generates a voltage across the RF amplifier 40 or a tissue load, for example, one or more internal loads located inside the electrosurgical hand device 20, 20', for example, load 80 (best shown in FIG. 5). The feedback system 60, in various embodiments, recovers the delivered current by using inherent shunt resistors (615, 625, 635) and measures the voltage across the shunt resistors. To measure the voltage, the feedback system 60 provides three voltage dividers (614, 624, 634) in parallel with the loads 20, 80. All measurements are converted to their real and imaginary components by the FPGAs 617, 627, and 637, in various embodiments. The real and imaginary components are sent to the primary microcontroller 50, whereby the feedback system 60 acts as a feedback device between the primary microcontroller 50 and the RF amplifier 40.

[0067] According to various embodiments, the feedback system 60 measures the analog RF output through a front-end circuit 611, 621, 631. The front-end circuit may include a shunt resistor 615, 625, 635 coupled to a respective preamplifier 613, 623, 633 to measure the current of the RF output. In various embodiments, the front-end circuit may include a voltage divider 614, 624, 634 coupled to a respective preamplifier 612, 622, 632 to measure the voltage of the RF output. The output of the preamplifier is provided to an analog-to-digital converter (ADC) 616, 626, 636, which results in the current and voltage measurements being digitized. The digitized values ​​are processed to derive the real and imaginary components of the voltage and current RF output. In various embodiments, the digitized values ​​from the respective analog-to-digital converter (ADC) are provided to an FPGA 617, 627, 637.

[0068] In various embodiments, electrosurgical generator 10 is configured to provide RF power in a low voltage mode during passive impedance assessment, which is automatically set by generator 10. In accordance with embodiments of the present invention, electrosurgical generator 10 is automatically set to the low voltage mode prior to execution of any device script. The device script, in various embodiments, represents a surgical procedure walk-through, which may include application and termination of RF energy to tissue. During medium or normal voltage mode, electrosurgical generator 10 according to embodiments of the present invention is configured to have an output RF energy of up to 150 V or 8 A and is primarily used for tissue sealing. During high voltage mode, electrosurgical generator 10 according to embodiments of the present invention is configured to have an output RF energy of up to 300 V or 4 A and is primarily used for tissue cutting. During low voltage mode, electrosurgical generator 10 according to embodiments of the present invention is configured to have an output RF energy of up to 10 V and 100 mA and is primarily used for passive tissue impedance assessment and measurement at levels that do not generate a physiological response in tissue.

[0069] According to various embodiments, a specific device script is stored on a particular electrosurgical hand device 20, 20' optimized for a particular surgical procedure to produce consistent electrosurgical seals and / or cuts of tissue. In various embodiments, RF output parameters or settings are defined in the device script and used by the electrosurgical generator 10 to adjust or control the particular surgical procedure and / or RF output of the electrosurgical hand device 20, 20'. The device script and associated RF output parameters, in various embodiments, are retrieved or transferred to the generator 10 when the electrosurgical hand device 20, 20' is connected to the generator 10. In one embodiment, the primary ARM processor 501 can retrieve the device script from memory storage attached to or integrated with the device key 21, which connects the electrosurgical device 20, 20' to the electrosurgical generator 10.

[0070] 9, a block diagram of an embodiment of the control system 100 of the electrosurgical generator 10 operating in a passive regulation mode is shown. In accordance with various embodiments of the present invention, the electrosurgical generator 10 is configured to provide a passive measurement regulation mode or a low voltage mode to ascertain whether the connected electrosurgical hand device 20, 20' can be used for a particular surgical procedure, such as, for example, sealing, lysing, and / or cutting tissue or blood vessels. Thus, the passive regulation mode is triggered at a predetermined time, for example, upon each power-up of the connected electrosurgical hand device 20, 20'. The passive mode is configured to detect open and / or shorted loads in the RF output path. In one embodiment, the open or shorted conditions are acceptable impedance ranges or impedance values ​​that are predetermined, and in various embodiments, are included with the connected electrosurgical hand device 20, 20' or otherwise predetermined by a device script associated with such electrosurgical hand device 20, 20'. In various embodiments, passive mode RF power has a lower static limit than other RF regulation modes and is used for a limited time span before normal RF regulation or operation of the electrosurgical generator 10 is initiated. The low level RF power does not generate a physiological response in tissue in various embodiments.

[0071] In various embodiments, when the electrosurgical generator 10 is operating in passive mode, the RF amplifier 40 provides a 350 kHz RF output through a relay to the connected electrosurgical instrument 20, 20'. As further described above, the RF output in low voltage or passive mode is limited to no more than 10 Vrms and / or no more than 100 mArms. The control system 100 regulates and measures the voltage and current through a feedback system 60. The primary microcontroller 50 determines whether a short and / or open condition is encountered based on the device script and the measured voltage and current data from the control system 100. In various embodiments, one or more electrodes (best shown in FIG. 9) are used in passive mode, and the location or selection of the electrodes, e.g., top, center, or bottom, may vary based on the location of the electrodes relative to the connected electrosurgical device, e.g., device 20, 20', and / or the tissue or blood vessel of the subject.

[0072] According to various embodiments, when the surgeon asserts the melt or disconnect switch, the electrosurgical control system 100 initiates a passive impedance evaluation that triggers or identifies a fault when a short or open condition is detected at the jaws 22 or distal working end of the electrosurgical hand device 20, 20'. If the passive impedance check is satisfactory, the primary ARM processor 501 executes the entire device script. In various embodiments, the primary ARM processor 501 commands the output of RF energy to other circuits of the electrosurgical generator 10 based on specific conditions, triggers, events, and timing and according to specific set points. In various embodiments, the primary ARM processor 501 ensures that the electrosurgical device delivers specific RF energy according to specific output set points (voltage, current, and power set points) and varies the RF output throughout the progress of the procedure or surgery in response to various triggers defined by the device script.

[0073] 10 illustrates a flow diagram of an embodiment of a passive regulation mode operation or process according to an embodiment of the present invention. The depicted portion of process 700 begins at step 702 where an algorithm initiates a passive mode as a starting point. According to various embodiments, the passive mode is initiated or triggered by a surgeon or other user with each activation of a connected electrosurgical hand device 20, 20'. After initiating the passive mode, the process proceeds to block 704 where an RF output is generated in a low voltage or passive mode and RF energy is provided to the connected electrosurgical hand device 20, 20'. In various embodiments, when the electrosurgical generator 10 operates in a passive or low voltage mode, the RF signal output from the RF amplifier 40 is limited to a specified voltage range (≦10V) and a specified current range (≦10mA) over a range of 5-500 ohm resistance.

[0074] With the passive mode RF output generated, processing flows to block 706 where the feedback system 60 measures electrical characteristics of the RF output. The control system 100 adjusts the output RF to a set point as dictated by the passive or low voltage mode in accordance with various embodiments of the present invention, and the feedback system 60 measures the voltage, current, and / or phase from the primary channel 601 and digitally provides some or all of the measurements to the primary microcontroller 50. After completion of the measurements and transmission of the measurement data, processing flows to block 708 where the primary FPGA 510 calculates or determines other electrical characteristics of the RF output based on the received data or readings and transmits some or all of the calculations to the ARM processor 501 of the primary microcontroller 50. Other electrical characteristics of the RF output in accordance with embodiments of the present invention may include tissue impedance loading and / or power. Once the calculation results are received by the primary ARM processor 510, processing flows to block 710 where the primary ARM processor 501 retrieves the device script and compares the calculation results, e.g., the calculated impedance load or the calculated tissue load, to the pre-set ranges set by the device script. In one embodiment, the device script is stored in a memory attached to or integral with the device key or connector 21, which connects the electrosurgical hand device 20, 20' to the electrosurgical generator 10.

[0075] A determination is made at step 712 whether the comparison result satisfies certain criteria set by the device script. Examples of certain criteria may include, but are not limited to, whether the comparison result or reading is within a maximum or minimum value set by the device script. If the comparison result or reading is not between the maximum and minimum values ​​set by the device script, processing flows from block 712 to block 714 where an error is generated to notify a user or surgeon of the error and / or to check the electrosurgical device and / or its position relative to the tissue or vessel. According to various embodiments, in order for RF energy to be delivered after such notification, the electrosurgical device 20, 20' must be restarted and passive tissue impedance evaluation, e.g., passive mode or low voltage mode, resumed.

[0076] If the comparison result or reading is between the maximum and minimum values ​​set by the device script, processing proceeds from block 712 to block 716 where the primary ARM processor 501 initiates all device scripts to provide optimized RF energy to seal, dissolve, and / or cut tissue or blood vessels.

[0077] As further described above and according to various embodiments, the control system 100 of the electrosurgical generator 10 can include one or more resolution settings, which in various embodiments include three settings: a low voltage setting, a normal or medium voltage setting, and a high voltage setting. These resolution settings are distinct from the adjustment modes, and in some embodiments, they require some adjustment to the circuitry that measures the RF power. Each setting is configured to require a different hardware configuration for the feedback system 60 and / or a different normalization algorithm in the calculations performed by the primary microcontroller 50. In various embodiments, the voltage measurement circuitry of the feedback system 60 uses a different resistor selection or configuration for each of the three settings. In various embodiments, the current measurement circuitry of the feedback system 60 uses the same resistor configuration for two of the settings, e.g., the normal and high voltage settings, and a different resistor configuration for the low voltage setting.

[0078] In one embodiment, while the electrosurgical generator 10 is operating in a passive mode, operations or processing assigned to the primary ARM processor 501 may be performed through the FPGA. In other embodiments, other control systems may be incorporated therein. In yet other embodiments, proportional, e.g., adjustment of the system to reach a set point, integral, e.g., area measurement between the error value and a time axis, and forecasting, e.g., prediction of future error based on the current error gradient, architecture, or any combination thereof, may be included to supplement or replace the control system measurements, calculations, and / or adjustments.

[0079] In various embodiments, the electrosurgical generator 10 can provide RF output with different waveform characteristics, for example, a square indicates a non-sinusoidal periodic waveform that alternates between a minimum and a maximum, a triangle indicates a non-sinusoidal periodic waveform with an asymmetrical slope to a maximum and a minimum, and / or a sawtooth indicates a non-sinusoidal waveform with a slope to a maximum and a steep drop to a minimum. Various embodiments of the present invention allow the electrosurgical generator 10 to provide RF output with different peak-to-rms ratios of the waveform, peak amplitude divided by RMS value, and / or crest factor characteristics, such as providing an ideal or perfect sine wave with a crest factor of 1.414.

[0080] The above description is provided to enable any person skilled in the art to make and use an electrosurgical device or system to perform the methods described herein, and describes the best mode of carrying out the invention contemplated by the inventor. However, various modifications will remain apparent to those skilled in the art. These modifications are contemplated to be within the scope of the present disclosure. Different embodiments or aspects of such embodiments may be shown and described in various figures throughout this specification. However, it should be noted that each embodiment and its aspects, although shown or described separately, can be combined with one or more of the other embodiments and its aspects, unless expressly stated otherwise. Each combination has not been explicitly described solely to facilitate the readability of this specification.

[0081] While the present invention has been described in certain aspects, many additional modifications and variations will become apparent to those skilled in the art. It is therefore to be understood that the present invention can be practiced using methods other than those specifically described, including various changes in size, shape, and materials, without departing from the scope and spirit of the invention. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive. [Explanation of symbols]

[0082] 50 Primary Microcontroller 60 Feedback System 100 Control System 501 Primary ARM Processor 512 Error Processor

Claims

1. 1. A digital closed loop control system for use with an electrosurgical generator that delivers electrosurgical RF energy to a surgical site, comprising: a feedback system for continuously monitoring an electrical characteristic of the delivered RF energy to the surgical site as a concurrent surgical condition and generating a digital RF signal related thereto; a microcontroller configured with a variable gain factor to adjust and control an RF amplifier in response to the generated RF signal from the feedback system to generate the delivered RF energy across a plurality of adjustment modes to provide optimal RF output for a surgical procedure under all surgical, operating, or procedural conditions; 1. A digital closed loop control system comprising:

2. 2. The digital closed loop control system of claim 1, wherein the feedback system is configured to measure an electrical property of the RF output through at least one channel and digitally transmit the measured data to the microcontroller.

3. 3. The digital closed loop control system of claim 2, wherein the microcontroller is configured to receive the measurement data and perform associated power calculations to obtain measured magnitudes of voltage, current, and power, and to calculate individual error values ​​for each of the plurality of regulation modes.

4. The microcontroller is further configured to select an adjustment mode based on the calculated error value; The adjustment mode is selected based on the most positive error value.

4. The digital closed loop control system of claim 3.

5. 4. The digital closed loop control system of claim 3, wherein the individual error values ​​are calculated by subtracting desired voltage, current, and power set points from the measured magnitudes of the voltage, current, and power.

6. the microcontroller is further configured to calculate a variable gain factor for each of the plurality of adjustment modes and select one variable gain factor based on the calculated error value; the variable gain is selected based on a most positive error value; 4. The digital closed loop control system of claim 3.

7. 2. The digital closed loop control system of claim 1, wherein the plurality of regulation modes includes one of a voltage, a current, and a power regulation mode.

8. the microprocessor includes a primary fully programmable gate array (FPGA) and a primary processor; the primary processor is configured to establish a desired RF power value or set point for each of the plurality of RF regulation modes; 2. The digital closed loop control system of claim 1.

9. The digital closed loop control system of claim 8 , wherein the desired RF value or set point is provided by a device script.

10. 2. The digital closed loop control system of claim 1, wherein the variable gain coefficients for the multiple adjustment modes are calculated by a specialized algorithm using a desired RF value or set point, a calculated magnitude of measurement data, a calculated tissue impedance load, and an accumulated error value, or any combination thereof.

11. 2. The digital closed loop control system of claim 1, wherein the variable gain factor enables the electrosurgical generator to have a deterministically damped stepped response under all changing surgical, operating and procedural conditions.

12. 10. The digital closed loop control system of claim 1, wherein the microprocessor is further configured with a preload function that enables seamless transition of the electrosurgical generator between each of the plurality of regulation modes.

13. 13. The digital closed loop control system of claim 12, wherein the preload function is configured to calculate the variable gain coefficient for the next regulation mode the electrosurgical generator is transitioning to and to preload this value into an accumulated error value.

14. 10. The digital closed loop control system of claim 1, wherein the microcontroller is configured to provide a variable integral control system for determining RF output of a Buck and H-bridge circuit of the RF amplifier.

15. 15. The digital closed loop control system of claim 14, wherein the microcontroller is configured to use a desired RF value or set point and a calculated tissue impedance load to drive a duty cycle value for the Buck circuit of the RF amplifier.

16. 15. The digital closed loop control system of claim 14, wherein the microcontroller is configured to drive a duty cycle value for the H-bridge circuit of the RF amplifier using an integrated signal generated by integrating the calculated error value of the selected mode and multiplying it by the variable gain factor.

17. 2. The digital closed loop control system of claim 1, wherein the feedback system is configured to measure an analog RF output through a front-end circuit, digitize the measurement data through an analog-to-digital converter (ADC), drive real and imaginary components of the measurement data through a fully programmable gate array (FPGA), and digitally transmit the real and imaginary components of the measurement data to the microcontroller.

18. 1. A method for dynamically controlling an electrosurgical generator for delivering electrosurgical RF energy through an electrosurgical instrument to a surgical site, comprising: retrieving desired RF settings or target values ​​for a plurality of RF adjustment modes and generating RF energy at the desired RF settings; measuring an electrical characteristic of the RF output through at least one channel from a feedback system and communicating its real and imaginary components to a microcontroller; receiving the real and imaginary components of measurement data and performing power calculations to obtain measurement data and tissue impedance loading magnitudes for each of the plurality of RF regulating modes; generating error signals for each of the plurality of RF tuning modes by subtracting the desired RF setting value from their respective calculated magnitudes, and selecting an tuning mode based on the calculated error value; calculating a variable gain coefficient for each of said plurality of adjustment modes using a special algorithm and selecting one of said variable gains based on a calculated error value; determining an output control signal for a Buck and H-bridge circuit of an RF amplifier of the electrosurgical generator; controlling an amount of RF power of the electrosurgical generator in response to the power control signal to maintain a desired power value of the generator; The method according to claim 1, further comprising:

19. The step of determining an output control signal further comprises: predicting an output voltage of the generator using the desired RF settings and a calculated tissue impedance load; setting a count for the Buck circuit of the RF amplifier using the expected output voltage; Further including:

20. The method of claim 18 .

20. The determining step comprises: generating an integrated signal by integrating the selected error signal, and multiplying the generated integrated signal by the selected variable gain factor; setting a count for the H-bridge circuit of the RF amplifier; Further comprising:

20. The method of claim 19 .

21. 20. The method of claim 18, wherein the power control signal for the RF amplifier buck circuit is used to roughly reach a neighborhood of the desired output value of the generator.

22. 20. The method of claim 18, wherein the power control signal to the H-bridge circuit of the RF amplifier is used to fine tune the amount of RF power to the desired output value of the generator.

23. 20. The method of claim 18, wherein the adjustment mode is selected based on a most positive error value.

24. 20. The method of claim 18, wherein the variable gain factor is selected based on a most positive error value.

25. 20. The method of claim 18, wherein the variable gain factor for each of the plurality of adjustment modes is calculated using a desired RF value or set point, a calculated magnitude of measurement data, a calculated tissue impedance load, and an integrated error signal, or any combination thereof.

26. 21. The method of claim 20, further comprising applying a preload function to the generated integrated signal to ensure a smooth transition of RF output when the generator switches between each of the plurality of regulation modes.

27. 27. The method of claim 26, wherein the preload function is calculated using the counts for the Buck and H-bridge circuits of the RF amplifier and the calculated tissue impedance load.

28. 20. The method of claim 18, wherein the plurality of RF regulation modes includes one of a voltage, a current, and a power regulation mode.

29. 20. The method of claim 18, wherein the desired RF settings or target values ​​are provided by a device script stored in a memory of the electrosurgical instrument or its device key.

30. 1. An electrosurgical system for performing a surgical procedure, comprising:

1. An electrosurgical generator adapted to deliver RF energy to a surgical site, the electrosurgical generator comprising a microcontroller including a processor and a primary fully programmable gate array (FPGA), the primary FPGA comprising: generating RF energy at a desired RF setting in an RF amplifier of said generator; causing receiving real and imaginary components of measurement data from a feedback system of the generator and performing power calculations to obtain measurement data and tissue impedance load magnitudes for a plurality of RF regulation modes; generating an error signal for each of the plurality of RF tuning modes and selecting one tuning mode based on a most positive error value; causing the use of a special algorithm to calculate a variable gain factor for each of the plurality of adjustment modes and selecting one variable gain factor based on the generated error signal; generating an integrated signal by integrating the selected error signal, and multiplying the generated integrated signal by the selected variable gain factor; causing a prediction of an output voltage of the generator using the desired RF setting and a calculated tissue impedance load; and causing the predicted output voltage and the generated integrated signal to be used to drive duty cycles for a Buck and an H-bridge circuit of the RF amplifier, respectively; the electrosurgical generator configured to an electrosurgical instrument connected to the electrosurgical generator, the electrosurgical instrument having at least one active electrode adapted to apply electrosurgical RF energy to tissue at the surgical site; 1. An electrosurgical system comprising:

31. 31. The electrosurgical system of claim 30, wherein the variable gain factor for each of the plurality of adjustment modes is calculated using a desired RF value or set point, a calculated magnitude of measurement data, a calculated tissue impedance load, and a generated integrated signal, or any combination thereof.

32. 31. The electrosurgical system of claim 30, wherein the error signal is generated by an error processor including an error calculator and an error selector for selecting the RF regulation mode.

33. 31. The electrosurgical system of claim 30, wherein the power calculations and tissue impedance load calculations are performed using a VCW (voltage, current, power) module having a separate load calculator.

34. 31. The electrosurgical system of claim 30, wherein the plurality of regulation modes includes one of voltage, current, and power regulation modes.

35. 31. The electrosurgical system of claim 30, wherein the primary FPGA is further configured to cause the integrated signal to be preloaded with a preload function that enables seamless transition of the generator among the multiple RF regulation modes.

36. 36. The electrosurgical system of claim 35, wherein the preload function is calculated using the duty cycle for the Buck and H-bridge circuits of the RF amplifier and the calculated tissue impedance load.

37. 31. The electrosurgical system of claim 30, wherein the feedback system comprises an analog input, digital processing, and a digital output.

38. 31. The electrosurgical system of claim 30, wherein the feedback system of the generator is configured to measure electrical properties of RF energy delivered to the surgical site across at least a main channel of the feedback system, digitize the measurements using an analog-to-digital converter (ADC), and drive real and imaginary components of the measurement data using a fully programmable gate array (FPGA).

39. 39. The electrosurgical system of claim 38, wherein the feedback system is further configured to digitally transmit the real and imaginary components of the measurement data to the microcontroller.

40. the feedback system includes at least one redundant channel; the measurement data from the redundant channel is constantly compared to that of the primary channel to ensure that the primary channel is operating within predetermined parameters and / or tolerances; 39. An electrosurgical system according to claim 38.

41. the FPGA of the feedback system is configured to perform I / Q demodulation on discrete voltage and current measurement samples to obtain real and imaginary samples; The DC components of the real and imaginary values ​​for the voltage and current measurements are obtained using a Discrete Fourier Transform.

39. An electrosurgical system according to claim 38.

42. 31. The electrosurgical system of claim 30, wherein the processor is configured to establish a desired RF power value or set point for each of the plurality of regulation modes.

43. 43. The electrosurgical system of claim 42, wherein the processor is configured to retrieve the desired RF power value or setting from a device script stored in a memory of the connected electrosurgical instrument or a device key therefor.

44. an RF amplifier for supplying RF energy; a feedback system adapted to continuously monitor an electrical characteristic of the delivered RF energy and generate a digital RF signal related thereto; a primary microcontroller programmed to calculate variable gain factors and preload functions that enable dynamic control of the delivered RF energy across multiple RF regulation modes and multiple RF resolution settings under all surgical, operating, and procedural conditions; 13. An electrosurgical generator comprising:

45. 45. The electrosurgical generator of claim 44, wherein the primary microcontroller is configured to regulate the RF output of the generator to a desired RF setting for each of the plurality of RF regulation modes and RF resolution settings.

46. the plurality of RF regulation modes includes one of voltage, current, and power regulation modes; the plurality of RF resolution settings include one of a low, a medium, and a high voltage setting; 45. An electrosurgical generator as claimed in claim 44.

47. 46. ​​The electrosurgical generator of claim 45, wherein the primary microcontroller includes a processor configured to establish the desired RF setting for each of the plurality of RF regulation modes and the plurality of RF resolution settings.

48. the desired RF settings are provided by a device script; The processor is further configured to retrieve the desired RF settings from the device script stored in a memory of the connected electrosurgical instrument or a device key therefor.

46. ​​An electrosurgical generator as claimed in claim 45.

49. 45. The electrosurgical generator of claim 44, wherein the feedback system is programmed to measure an electrical property of the RF output through at least one channel and digitally transmit the measurement data to the primary microcontroller.

50. 45. The electrosurgical generator of claim 44, wherein the primary microcontroller is programmed to receive the measurement data and perform associated power calculations in response to the generated RF signal from the feedback system to obtain measured magnitudes of voltage, current and power, and to calculate individual error values ​​for each of the plurality of RF regulation mode and RF resolution settings.

51. the individual error values ​​are calculated by subtracting the desired RF settings for voltage, current, and power from the measured magnitudes of the voltage, current, and power; The primary microcontroller is further programmed to select an RF tuning mode based on the calculated error value.

51. An electrosurgical generator as claimed in claim 50.

52. the variable gain factor is calculated for each of the plurality of RF tuning modes using a special algorithm; The primary microcontroller is further programmed to select a variable gain factor based on the calculated error value.

45. An electrosurgical generator as claimed in claim 44.

53. 45. The electrosurgical generator of claim 44, wherein the primary microcontroller is further programmed to determine output control signals for the Buck and H-bridge circuits of the RF amplifier, thereby providing an optimal RF output for a surgical procedure under all operative, operating and procedural conditions in response to said output control signals.

54. 54. The electrosurgical generator of claim 53, wherein the output control signal to the buck circuit of the RF amplifier is determined by predicting the RF output of the generator using the desired RF setting and a calculated impedance load, and driving that duty cycle to the buck circuit of the RF amplifier.

55. 54. The electrosurgical generator of claim 53, wherein the output control signal to the H-bridge circuit of the RF amplifier is determined by generating an integral signal of a selected individual error value and multiplying the generated integral signal by a selected variable gain factor and driving the duty cycle to the H-bridge circuit of the RF amplifier.

56. 56. The electrosurgical generator of claim 55, wherein the primary microcontroller is further programmed to calculate a preload function and preload the generated integral signal with the preload function value.

57. 57. The electrosurgical generator of claim 56, wherein the preload function is calculated using the duty cycles obtained for the Buck and H-bridge of the RF amplifier.

58. 1. A method for impedance assessment of an electrosurgical instrument connected to an electrosurgical generator prior to performing a surgical procedure, comprising: initiating a low voltage or passive mode upon start-up of the connected electrosurgical instrument; generating an RF power limited to a value determined by said low voltage mode; measuring an electrical characteristic of the RF output and digitally transmitting the measurement data to a microcontroller of the electrosurgical generator; calculating other electrical characteristics of the RF output based on the received measurement data and transmitting the calculation results to a primary processor within the microcontroller; determining whether the calculation results satisfy certain criteria established by a device script of the connected electrosurgical instrument; The method according to claim 1, further comprising:

59. retrieving the device script stored in a memory of the connected electrosurgical instrument or its device key; the retrieving step being performed by the primary processor of the microcontroller; 60. The method of claim 58.

60. 60. The method of claim 58, further comprising the step of comparing the calculation result, once received by the primary processor, against a preset range defined by the device script.

61. generating a device error when the calculation result does not satisfy the certain judgment criterion; The certain criteria may include maximum and / or minimum values ​​set by the device script.

60. The method of claim 58.

62. and initiating a complete device script for performing the surgical procedure if the calculations satisfy the certain criteria; The certain criteria may include maximum and / or minimum values ​​set by the device script.

60. The method of claim 58.

63. 62. The method of claim 61, further comprising restarting or reconnecting the electrosurgical device if the device error first occurs.

64. 61. The method of claim 60, wherein the comparing and determining steps are performed by the primary processor of the microcontroller.

65. 60. The method of claim 58, wherein the primary processor comprises an Advanced Reduced Instruction Set Machine (ARM) processor.

66. 60. The method of claim 58, wherein said calculating step is performed by a primary FPGA (field programmable gate array) of said microcontroller.

67. 60. The method of claim 58, wherein the step of measuring the electrical characteristics of the RF output is performed over at least one channel of a feedback system from the electrosurgical generator.

68. 60. The method of claim 58, wherein the RF output in the low voltage or passive mode is limited to a specified voltage range (< 10V) and a specified current range (< 10mA) over a range of 5-500 ohms.

69. an RF amplifier for supplying RF energy; a microcontroller configured to dynamically control the delivered RF energy across at least one tuning mode from a plurality of RF tuning modes and a plurality of RF resolution settings; 13. An electrosurgical generator comprising:

70. an RF amplifier for supplying RF energy; a microcontroller configured to determine at least one of a variable gain factor and a preload function to dynamically control the delivered RF energy; 13. An electrosurgical generator comprising:

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