Surgical generator and method

Abstract

This disclosure relates to a surgical generator and method, the surgical generator being configured to generate controlled electrical power for a therapeutic signal and to provide the controlled electrical power to biological tissue electrically connected to an instrument. The surgical generator includes: a control circuit connected to an electrical energy source, the electrical energy source being electrically coupled to the instrument and configured to generate the therapeutic signal; the control circuit being configured to: control the electrical power of the therapeutic signal provided to the biological tissue during a portion of a non-closed treatment phase according to a treatment plan by monotonically increasing the electrical power as a function of resistance, wherein the electrical power decreases to a non-zero level between the non-closed treatment phase and a subsequent treatment phase.

Description

[0001] This application is a divisional application of patent application No. 202080034752.3 entitled "Electrosurgical System and Method", filed on May 7, 2020, with international application number PCT / US2020 / 031857, and entered the Chinese national phase on November 9, 2021.

[0002] Priority Statement

[0003] This application relates to (1) U.S. Provisional Application No. 62 / 845,647, filed May 9, 2019, entitled “ELECTROSURGICALLY SEALING BIOLOGICAL TISSUE BY CONTROLLING POWER PROVIDEDTHERETO” by Kester J. Batchelor et al., and (2) U.S. Provisional Application No. 62 / 905,318, filed September 24, 2019, entitled “ELECTROSURGICALLY SEALING BIOLOGICAL TISSUE BY CONTROLLING POWER PROVIDED THERETO” by Kester J. Batchelor et al., and (3) U.S. Provisional Application No. 62 / 905,318, filed September 24, 2019, entitled “CORRECTING TISSUE RESISTANCE MEASUREMENTS USING TEMPORAL” by Huisun Wang et al., filed September 24, 2019. The U.S. Provisional Application No. 62 / 905,366 concerning “DATA”, and relating to (4) U.S. Provisional Application No. 62 / 905,337 concerning “PREDICTIVE PHASE CONTROL OFAN ELECTROTHERAPEUTIC PROCEDURE” filed on September 24, 2019 by Huisun Wang et al., and relating to (5) U.S. Provisional Application No. 62 / 905,345 concerning “PULSED ELECTRICALPOWER PROVIDED TO SEALED TISSUE TO REDUCE TISSUE STICKING” filed on September 24, 2019 by Huisun Wang et al., and relating to (6) U.S. Provisional Application No. 62 / 905,345 concerning “IMPEDANCEPHASE DETECTION FOR SHORT CIRCUIT” filed on September 24, 2019 by Wayne Williams et al., and relating to (6) U.S. Provisional Application No. 62 / 905,337 concerning “PREDICTIVE PHASE CONTROL OFAN ELECTROTHERAPEUTIC PROCEDURE” filed on September 24, 2019 by Wayne Williams et al., and relating to (7) U.S. Provisional Application No. 62 / 905,337 concerning “PREDICTIVE PHASE CONTROL OFAN ELECTROTHERAPEUTIC PROCEDURE” filed on September 24, 2019 by Wayne Williams et al., and relating to (8) U.S. Provisional Application No. 62 / 905,337 concerning “PREDICTIVE PHASE CONTROL OFAN ELECTROTHERAPEUTIC PROCEDURE” filed on September 24, 2019 by Wayne Williams et al., and relating to (9) U.S. Provisional Application No. 62 / 905,337 concerning “PREDICTIVE The entire contents of each of the U.S. Provisional Application No. 62 / 905,360 entitled "Prediction" are incorporated herein by reference in their entirety, and the benefit of priority of each application is claimed herein. Background Technology

[0004] Electrosurgery is the application of electrical signals—therapeutic signals—to induce changes in the biological tissues of a surgical patient in a specific way. Various electrosurgical techniques are used to cut, coagulate, dry, or electrocauterize biological tissues. These and other electrosurgical techniques can be performed during a variety of medical procedures, such as laparoscopic surgery. These procedures include: appendectomy, cholecystectomy, colectomy, cystectomy, gastric banding, gastric bypass, hernia repair, nephrectomy, Nissen fundoplication, prostatectomy, sleeve gastrectomy, etc. Each of these procedures may have one or more electrotherapy phases, such as an inquiry phase, a heating phase, a drying phase, or a cauterization phase.

[0005] The electrotherapy signals used in such a medical procedure can be generated by an electrosurgical generator and then delivered to the biological tissue via an electrosurgical instrument electrically connected to the generator. The electrosurgical instrument can be configured to mechanically and electrically engage the biological tissue to which the electrotherapy signals are delivered. Various types of such electrosurgical instruments can be used, including, for example, various types of forceps, conductive scrapers, and electrosurgical pads.

[0006] Different medical procedures can achieve different electrotherapy signals to produce results specific to those procedures. Various electrophysiological parameters of the electrotherapy signals provided to the joined biological tissue can be used to characterize these signals. These parameters include: polarity (unipolar, bipolar), AC and / or DC, frequency, signal amplitude, rise and fall curves, etc. The electrosurgical generator that generates these various electrotherapy signals can control one or more of these parameters to provide an electrotherapy signal that produces effective results in the biological tissue joined by the electrosurgical instrument. Summary of the Invention

[0007] The apparatus and related methods relate to a system for providing controlled electrical power to biological tissue. The electrosurgical system includes forceps having opposing jaw members configured to open and close. The forceps also has a handle with clamping levers configured to open and close the opposing jaw members. When closed, the opposing jaw members are configured to clamp biological tissue between the opposing jaw members in a manner that provides electrical communication between the opposing jaw members via the clamped biological tissue. The electrosurgical system also includes an electrosurgical generator electrically coupled to the forceps. The electrosurgical generator includes an electrical energy source that is electrically connected to the opposing jaw members when the electrosurgical generator is electrically coupled to the forceps. The electrical energy source is configured to generate an electrotherapy signal. The electrosurgical generator includes control circuitry configured to provide the electrotherapy signal to the clamped biological tissue during an electrotherapy phase. The electrical power of the provided electrotherapy signal is controlled according to the electrotherapy protocol.

[0008] According to one aspect of the invention, a surgical generator is provided, the surgical generator being configured to generate a controlled electrical power for a therapeutic signal and to provide the controlled electrical power to biological tissue electrically connected to an instrument, the surgical generator comprising: a control circuit connected to an electrical energy source electrically coupled to the instrument and configured to generate the therapeutic signal, the control circuit being configured to: monotonically increase the electrical power as a function of resistance, and control the electrical power of the therapeutic signal provided to the biological tissue during a portion of a non-closed treatment phase according to a treatment plan, wherein the electrical power decreases to a non-zero level between the non-closed treatment phase and a subsequent treatment phase.

[0009] According to another aspect of the invention, a method is provided for delivering controlled electrical power of a therapeutic signal to biological tissue electrically connected to an instrument, the method comprising: generating the therapeutic signal using electrical energy coupled to the instrument; and controlling the electrical power of the therapeutic signal supplied to the biological tissue during a portion of a non-closed treatment phase according to a treatment plan by monotonically increasing the electrical power as a function of resistance, wherein the electrical power decreases to a non-zero level between the non-closed treatment phase and a subsequent treatment phase.

[0010] According to another aspect of the invention, a method is provided for delivering controlled electrical power of a therapeutic signal to biological tissue electrically connected to an instrument, the method comprising: generating the therapeutic signal using electrical energy coupled to the instrument; and controlling the electrical power of the therapeutic signal supplied to the biological tissue during a portion of a non-closed treatment phase according to a treatment plan by monotonically increasing the electrical power as a function of current, wherein the electrical power decreases to a non-zero level between the non-closed treatment phase and a subsequent treatment phase.

[0011] Some examples relate to an electrosurgical generator for providing controlled electrical power to biological tissue joined by electrosurgical instruments. The electrosurgical generator includes an electrical connector configured to electrically couple the electrosurgical instruments to the generator to provide electrical communication between the generator and the joined biological tissue. The generator includes an electrical energy source electrically coupled to the electrical connector and configured to generate an electrotherapy signal. The generator also includes control circuitry configured to provide the electrotherapy signal to the joined biological tissue during an electrotherapy phase. The electrical power of the electrotherapy signal is controlled to be provided to the joined biological tissue according to the electrotherapy protocol.

[0012] Some examples relate to a method for providing controlled electrical power to biological tissue joined by an electrosurgical instrument. The method includes the step of joining the biological tissue via the electrosurgical instrument in a manner that provides electrical communication between the electrosurgical instrument and the joined biological tissue. The method proceeds to the step of providing an electrotherapy signal to the joined biological tissue via an electrical energy source electrically connected to the electrosurgical instrument during an electrotherapy phase. The method further includes the step of controlling the electrical power of the provided electrotherapy signal according to an electrotherapy protocol. Attached Figure Description

[0013] Figure 1 This is a three-dimensional diagram of an electrosurgical system that provides electrotherapy to the biological tissues of surgical patients.

[0014] Figure 2 This is a block diagram of an electrosurgical system used to close biological tissues joined by electrosurgical instruments.

[0015] Figures 3A to 3B This is a flowchart of a method for sealing biological tissue joined by electrosurgical instruments.

[0016] Figure 4 It is a graph depicting an example of an electrical power scheme used to control the electrical power supplied to a closed biological tissue.

[0017] Figure 5 This is a flowchart depicting an example of an open-circuit examination technique that can be used in a surgical system.

[0018] Figure 6 This is a flowchart of a biological tissue closure method that uses an electrical power scheme corresponding to the size of the biological tissue coupled with an electrosurgical instrument.

[0019] Figure 7A It is a graph depicting the measured tissue resistance as a function of the jaw temperature of the pliers.

[0020] Figure 7B It is a graph depicting the jaw temperature versus time after the termination power is applied.

[0021] Figure 8 It is a graph depicting the resistance compensation versus time after power is applied.

[0022] Figure 9 A flowchart is shown illustrating a method for compensating for measurements of tissue resistance as a function of time after power is applied.

[0023] Figures 10A to 10D It is a graph of the electrical parameters of the electrotherapy signal of an electrotherapy with pulsed adhesion reduction component.

[0024] Figure 11This is a flowchart of a method for reducing adhesion between biological tissues and electrosurgical instruments.

[0025] Figure 12 It is a graph depicting examples of the impedance-angle / time relationship of biological tissues with and without metallic objects.

[0026] Figure 13 This is a flowchart of a method for determining the presence of a metallic object in biological tissue joined by electrosurgical instruments.

[0027] Figure 14 This is a flowchart depicting an example of a double-boundary technique that can be used in a surgical system.

[0028] Figure 15 This is a flowchart depicting an example of an open-circuit examination technique that can be used in a surgical system.

[0029] Figure 16 This is a flowchart depicting another example of an open-circuit examination technique that can be used in a surgical system.

[0030] Figure 17 This is a flowchart illustrating an example of a power correction technique that can be used in a surgical system.

[0031] Figure 18 This is a simplified block diagram of an example of a combination of ultrasonic energy and electrosurgical energy systems that can realize the various technologies disclosed herein.

[0032] Figure 19 This is a flowchart illustrating an example of a heat margin reduction technique that can be used in a combined ultrasound energy and electrosurgical energy system.

[0033] Figure 20 This is a flowchart illustrating an example of thermal margin control techniques that can be used in electrosurgical systems.

[0034] Figure 21 This is a flowchart illustrating another example of thermal margin control techniques that can be used in electrosurgical systems.

[0035] Figures 22A to 22D A flowchart depicts an example of an energy delivery technology that can utilize the amount of energy delivered to biological tissues in its decision-making process.

[0036] Figure 23 It is an example of a graph depicting the relationship between changes in the measured electrical parameter value and changes in power.

[0037] Figure 24 This is a flowchart illustrating another example of a power correction technique that can be used in surgical systems. Detailed Implementation

[0038] The apparatus and related methods involve applying electrotherapy signals to biological tissue joined by electrosurgical instruments. The control of various electrical quantities of these electrotherapy signals, and specific electrosurgical techniques for performing such control, will be disclosed below. This specification is organized into sections entitled i) Electrical power control of electrotherapy signals ( Figures 1 to 4 ); ii) Predictive phase control of electrotherapy signals ( Figures 5 to 6 ); iii) Correction of the measured resistance of conjoined biological tissues ( Figures 7A to 7B and Figure 9 ); iv) Modification of initial impedance ( Figure 9 v) Reduce the adhesion of biological tissue to electrosurgical instruments by pulsed electrical power of the electrotherapy signal. Figures 10A to 10D and Figure 11 vi) Determine the presence of conductive foreign bodies in biological tissue joined by electrosurgical instruments. Figure 12 and Figure 13 vii) Use the short-circuit error capture between the trigger value and the escape value. Figure 14 viii) Open-circuit check of impedance-limited endpoint waveforms Figure 15 and Figure 16 ); ix) Alternating power correction output in low-accuracy hardware systems ( Figure 17 x) Reduced heat margin combined energy equipment ( Figure 18 and Figure 19 ); xi) is a graded impedance value used to control the thermal margin in systems with slow CPUs. Figure 20 and Figure 21 ); xii) Energy consumption monitoring and open circuit assessment ( Figures 22A to 22D (xiii) the dwell time between pulses; and (xiv) the incremental adjustment of control parameters as a function of the monitored variable. The techniques are described in these separate sections for illustrative purposes only. Each of these techniques may be used in combination with one or more of the other techniques described in this disclosure, unless expressly stated otherwise.

[0039] Electrical power control of electrotherapy signals ( Figures 1 to 4 )

[0040] Electrosurgical closure or coagulation of biological tissue joined by electrosurgical instruments is an electrosurgical technique used in various medical procedures. Joined biological tissue can be electrosurgically closed by heating it in a controlled manner. In some medical procedures, the biological tissue being closed is a blood vessel. Heating the blood vessel causes the collagen found in the vessel wall to denature. This denatured collagen forms a gel-like substance that acts as a glue between the vessel walls. When forced together and held together while cooling, the opposing walls of the blood vessel form a closure.

[0041] Careful control of vessel heating is crucial, ensuring that neither too little nor too much energy is supplied. Excessive energy can lead to carbonization and / or burns of the vessel wall. Insufficient energy may result in poor vessel closure. One indicator of closure quality is the pressure differential the closed vessel can withstand without rupturing. Poor-quality closures can be compromised if the pressure applied to the closed vessel exceeds a certain threshold.

[0042] The rate at which energy is delivered to the blood vessels can also be carefully controlled to facilitate rapid execution of electrosurgical procedures. Rapid execution of electrosurgical procedures reduces the time and complexity of these processes. However, the heating rate should not be so rapid as to cause uncontrolled boiling of the fluids within the biological tissue. Uncontrolled boiling can cause rupture of the joined or nearby biological tissue and / or compromise the quality of the closure.

[0043] Heating of the joined biological tissue can be controlled by controlling the electrical power of the electrotherapy signal supplied to and dissipated by the joined biological tissue. Such electrical power can be controlled according to a closure scheme. For example, the closure scheme can indicate the product of the voltage difference across the joined biological tissue and the current conducted by the joined biological tissue. Thus, the closure scheme is an electrical power scheme. In some examples, the electrotherapy signal can be reduced or terminated in response to a termination criterion. In some examples, the termination criterion is a current characteristic, such as a decrease in the current conducted by the joined biological tissue. In some examples, the termination criterion is a resistance characteristic, such as an increase in the resistance of the joined biological tissue. Such an increase in resistance exceeding a predetermined incremental resistance value can be used as a termination criterion, for example, where the predetermined incremental resistance value is the difference between the measured resistance (or impedance) and the lowest value of the resistance (or impedance) measured in the pulse. In some examples, the termination criterion is a time condition, such as a predetermined duration or a duration calculated based on some conditions.

[0044] Electrical impedance is complex and therefore includes a real component (resistance) and an imaginary component (reactance). This document describes techniques for using impedance or resistance. It should be understood that when complex impedance values ​​are available, these values ​​can be used in place of resistance values. Conversely, when complex impedance values ​​are not available, resistance values ​​can be used in place unless otherwise stated.

[0045] Furthermore, many of the following techniques describe the delivery of electrosurgical energy to biological tissue. Unless otherwise stated, each of these techniques can deliver electrosurgical energy using controlled power or controlled voltage techniques. In controlled power implementations, control circuitry can, for example, control the delivery of electrosurgical energy using the product of voltage and current applied across the connected biological tissue, according to a plan or scheme. For example, control circuitry can control the delivery of constant power or monotonically increasing power during a specific phase, such as a drying phase.

[0046] This document specifically describes one or more techniques for delivering electrotherapy, which can be delivered according to a treatment or other plan. The plan may include formulations, prescriptions, protocols, methods, etc. The plan may include one or more temporal aspects, such as the timing, frequency, type, relative combination (e.g., coagulation relative to a cut) of occurrence or recurrence (or prohibition or suppression). The plan may include electrotherapy waveform information, such as pulse width, duty cycle, on-time duration, off-time duration, repetition rate, amplitude, phase, etc. The plan need not be static or a priori in nature, but may include one or more dynamic aspects, such as those that can be modified or managed, for example, through diagnostic, procedural, or other information acquired during or between electrotherapy delivery instances, including in a closed-loop or other feedback manner. One or more aspects of the plan may be customized, for example, for a specific patient, patient subgroup (e.g., patients sharing one or more specified characteristics), or patient group, for example, based on stored patient data, or through user input, such as that provided by the patient or caregiver. The plan may include one or more conditional aspects, such as one or more branch conditions, which may be determined using patient characteristics, diagnostic measures, efficacy determination, or operational characteristics of the device or its environment. Such branch conditions may be determined automatically by the device (e.g., without user input) or may involve user input, for example, provided before, during, or after one or more operational sections of the electrotherapy device according to the plan. The plan may involve communicating with or using another device, such as receiving or providing one or any combination of inputs, outputs, or instructions, operational parameters, or measurement data. One or more aspects of the plan may be recorded or encoded on a medium (e.g., a computer or other machine-readable medium, which may be a tangible medium).

[0047] In controlled voltage implementations, the control circuit can, for example, control the voltage of the delivered electrosurgical energy according to a plan, scheme, or program. For instance, the control circuit can control the delivery of a constant voltage or a monotonically increasing voltage during a specific phase, such as a drying phase.

[0048] Figure 1 This is a three-dimensional diagram of an electrosurgical system that delivers electrical therapy to the biological tissues of a surgical patient. Figure 1 In this embodiment, the electrosurgical system 10 includes an electrosurgical generator 12 and forceps 14, which are shown as attachment sites for biological tissue 16. The electrosurgical generator 12 generates an electrotherapy signal, which is provided to the attachment site for biological tissue 16 via the forceps 14. Although Figure 1 The forceps 14 are depicted engaging biological tissue and delivering electrotherapy signals to the biological tissue 14, but various types of electrosurgical instruments (such as those disclosed above) can be used for such purposes.

[0049] Various types of forceps can also be used to deliver electrotherapy signals to biological tissue 14. For example, forceps 14 can be medical forceps, cutting forceps, or electrosurgical forceps (e.g., monopolar or bipolar forceps). In some examples, forceps 14 can be used in medically relevant procedures, such as open and / or laparoscopic medical procedures, to manipulate, engage, grasp, cut, burn, close, or otherwise affect blood vessels, biological tissue, veins, arteries, or other anatomical features or objects.

[0050] like Figure 1 As shown, the pliers 14 include a handle 18, a shaft assembly 20, a blade assembly 22, and a clamping assembly 24. In some examples, such as in... Figure 1 In the example shown, forceps 14 are electrically connected to an electrosurgical generator 12, which generates an electrotherapy signal and provides the generated signal to forceps 14. Forceps 14 then electrically delivers the electrotherapy signal to clamping assembly 24 and / or a remote pad, which can be used for various electrosurgical techniques such as cauterization, closure, or other such electrosurgical techniques.

[0051] The handheld component 18 includes a handle 26, a clamping lever 28, a knife trigger 30, an electrotherapy actuation button 32, and a rotating wheel 34. The clamping assembly 24 includes a first jaw member 36 and a second jaw member 38. A shaft assembly 20 is connected to the handheld component 18 at its proximal end and to the clamping assembly 24 at its distal end. The shaft assembly 20 extends distally from the handheld component 18 to the clamping assembly 24 along a longitudinal direction 40.

[0052] The shaft assembly 20 functions to allow a portion of the forceps 14 (e.g., the gripping assembly 24 and the distal portion of the shaft assembly 20) to be inserted into the patient or other anatomical structure, while the remaining portions of the forceps 14 (e.g., the handle 18 and the remaining proximal portion of the shaft assembly 20) remain outside the patient or other anatomical structure. Although in Figure 1 The shaft assembly 20 is shown as substantially straight, but in other examples, it may include one or more angles, bends, and / or arcs. The shaft assembly 20 may be a cylinder with a circular, elliptical, or other cross-sectional profile, or another elongated member extending from the handpiece 18 to the clamping assembly 24. In some examples, the shaft may be bendable, steerable, or deflectable.

[0053] In some examples, such as in Figure 1 In the example, shaft assembly 20 may include an elongated hollow member (e.g., a tubular outer shaft) that surrounds blade assembly 22 and a mechanical linkage to couple blade assembly 22 to blade trigger 30. Typically, the shaft assembly can be any elongated member with sufficient stiffness to deliver force in the longitudinal direction 40. Shaft assembly 20 may also include conductive elements (e.g., wires, conductive outer shafts and / or conductive inner shafts, etc.) to provide electrical communication between handpiece 18 and clamping assembly 24, thereby delivering electrotherapy signals.

[0054] The gripping lever 28 of the handheld component 18, the knife trigger 30, the electrotherapy actuation button 32, and the rotating wheel 34 are all configured to cause various actuations of the shaft assembly 20, typically located at its distal end. For example, actuation of the gripping lever 28 is configured to control the operation of the gripping assembly 24 at the distal end of the shaft assembly 20. The gripping lever 28 is available in an open configuration position ( Figure 1 A clamping actuator (shown) moves between a closed configuration position and a clamping position, wherein the clamping lever 28 moves proximally toward the handle 26. The movement of the clamping lever 28 proximally toward the handle 26 to the closed configuration position causes the clamping assembly 24 to change from an open configuration to a closed configuration. The distal movement of the clamping lever 28 (e.g., release of the clamping lever 28) to the open configuration position causes the clamping assembly 24 to change from a closed configuration to an open configuration.

[0055] By opening the construction ( Figure 1 The transition between the open and closed configurations of the clamping assembly 24 is achieved by moving one or more of the first jaw member 36 and the second jaw member 38 between the open and closed configurations, in which the first jaw member 36 and the second jaw member 38 are spaced apart, and in the closed configuration, the gap between the first jaw member 36 and the second jaw member 38 is reduced or eliminated. Various electrosurgical instruments engage biological tissue 16 in various ways. In some electrosurgical instruments, for example in… Figure 1 In the illustrated electrosurgical instrument, the first jaw member 36 and the second jaw member 38 may be opposed to each other. In the depicted example, the first jaw member 36 and the second jaw member 38 are configured to clamp biological tissue 16 therebetween in such a way that electrical communication is provided between the opposing jaw members 36 and 38 via the clamped biological tissue 16. Other electrosurgical instruments may engage biological tissue in other ways.

[0056] The mechanical linkage within the shaft assembly 20 can be configured to move one or more of the first jaw member 36 and the second jaw member 38 between an open and a closed configuration in response to actuation of the clamping lever 28. An example of a mechanism for moving the clamping assembly between the open and closed configurations can be found in U.S. Patent Publication No. 2017 / 0196579, entitled “FORCEPS JAW MECHANISM,” filed January 10, 2017, by Batchelor et al., the entire contents of which are incorporated herein by reference.

[0057] The actuation of the blade trigger 30 is configured to control the operation of the blade assembly 22 located at the distal end of the shaft assembly 20. The blade assembly 22 is configured to cut, remove, or otherwise affect biological tissue or other objects clamped between the first jaw member 36 and the second jaw member 38. The blade trigger 30 is capable of being in a retracted configuration position (…). Figure 1 A blade actuator (shown) moves between an extended or retracted configuration position, wherein a blade trigger 30 moves proximally toward a handle 26 to cause the blade assembly 22 to cut biological tissue 16 clamped between a first jaw member 36 and a second jaw member 38. Moving the blade trigger 30 proximally toward the handle 26 to the extended configuration position causes the cutting blade of the blade assembly 22 to engage the biological tissue 16, thereby cutting the biological tissue 16. Distal movement of the blade trigger 30 (e.g., release of the blade trigger 30) causes the blade to retract from the clamped biological tissue 16. For example, a mechanical linkage within the shaft assembly 20 may be configured to engage and retract the blade from the engaged biological tissue 16.

[0058] The rotating wheel 34 is configured to control the rotational configuration of one or more of the blade assembly 22 and the clamping assembly 24 at the distal end of the shaft assembly 20, and / or to control the rotational configuration of the shaft assembly 20. Movement (e.g., rotation) of the rotating wheel 34 causes one or more of the shaft assembly 20, the blade assembly 22, and the clamping assembly 24 to rotate about an axis extending in the longitudinal direction 40. This rotational control facilitates the alignment of the clamping assembly and / or the blade assembly with the clamped biological tissue 16.

[0059] The electrotherapy actuation button 32 is configured to control the generation of an electrotherapy signal and / or the delivery of the electrotherapy signal to the engaged biological tissue 16. Actuation of the electrotherapy actuation button 32 causes an electrotherapy signal from, for example, an electrosurgical generator 12 to be applied to one or more of the first jaw member 36, the second jaw member 38, the remote pad (not shown), or other portions of the forceps 14 to cauterize, seal, or otherwise electrically influence the patient or other anatomical structures. An example of a handpiece utilizing a clamping lever, a knife trigger, a rotating wheel, and an electrotherapy actuation button can be found in U.S. Patent No. 9,681,883, filed June 20, 2017, entitled “FORCEPS WITH AROTATION ASSEMBLY” by Windgassen et al., the entire contents of which are incorporated herein by reference.

[0060] Figure 2 This is a block diagram of an electrosurgical system used to close biological tissues joined by electrosurgical instruments. Figure 2 In this electrosurgical system 10, therein, there is an electrosurgical generator 12 and an electrosurgical instrument 14'. The electrosurgical instrument 14' can be any electrosurgical instrument configured to engage biological tissue and deliver an electrotherapy signal to the biological tissue. The electrosurgical generator 12 is configured to generate an electrotherapy signal, such as a high-frequency (AC) electrical signal, which the electrosurgical instrument 14' delivers to the engaged biological tissue 16.

[0061] In some examples, the electrosurgical instrument 14' is a pair of forceps having a handpiece coupled via a shaft assembly to opposing jaw members, for example... Figure 1 The forceps 14 are depicted in the image. In other examples, the electrosurgical instrument 14' is a conductive tongue, conductive pad, or other electrosurgical device. These different types of electrosurgical instruments have various ways of engaging biological tissue (e.g., clamping, contacting, circling, penetrating, radiating, etc.).

[0062] The electrosurgical generator 12 includes an instrument interface 42, an electrical power source 44, measurement circuitry 46, control circuitry 48, and a user interface 50. The instrument interface 42 may include, for example, a signal driver, a buffer, an amplifier, ESD protection devices, and an electrical connector 52. The electrical connector 52 is configured to electrically couple an electrosurgical instrument 14' to the electrosurgical generator 12 to provide electrical communication between the electrosurgical generator 12 and the electrosurgical instrument 14'. This electrical communication can be used to transmit operating power and / or electrical signals therebetween. The electrosurgical instrument 14' can further provide electrical communication between the electrical connector 52 and the biological tissue thereby joined.

[0063] Electrical energy source 44 is configured to generate an electrotherapy signal that is delivered to the joined biological tissue via an electrically connected electrosurgical instrument 14'. The generated electrotherapy signal can be controlled to achieve the desired outcome for a specific electrosurgical procedure. In one example, for instance, the electrotherapy signal is configured to resistively heat the joined biological tissue, thereby surgically influencing (e.g., closing) the joined biological tissue. This control over the electrotherapy signal will be further disclosed below.

[0064] Measurement circuit 46 is configured to measure one or more electrical parameters of the biological tissue joined by the connected electrosurgical instrument 14'. Measurement circuit 46 is electrically connected to the connected electrosurgical instrument 14' when the electrosurgical generator 12 is electrically connected via electrical connector 52. Various examples of measurement circuit 46 are configured to measure various electrical parameters. For example, measurement circuit 46 may be configured to measure the voltage difference transmitted across the joined biological tissue and / or the current conducted by the joined biological tissue. In some examples, measurement circuit 46 may be configured to measure the phase angle between the voltage difference transmitted across the joined biological tissue and the current conducted by the joined biological tissue. In some examples, measurement circuit 46 is configured to measure DC and / or AC electrical parameters of the joined biological tissue.

[0065] Measured parameters, such as the voltage difference transmitted across the junctional biological tissue and / or the current conducted by the junctional biological tissue, can be used to determine other electrical parameters. For example, measurements of the voltage difference delivered across the junctional biological tissue and / or the current conducted by the junctional biological tissue, and the phase angle between the voltage difference and the current, can be used to determine the resistance of the junctional biological tissue. Measurements of the voltage difference delivered across the junctional biological tissue and / or the current conducted by the junctional biological tissue, and the phase angle between the voltage difference and the current, can also be used to determine the complex impedance of the junctional biological tissue. Measurements of the voltage difference delivered across the junctional biological tissue and / or the current conducted by the junctional biological tissue, and the phase angle between the voltage difference and the current, can also be used to determine the apparent power (VA) and / or actual power (W) supplied to the junctional biological tissue.

[0066] Such measurements of electrical parameters can be used to control electrotherapy signals during delivery to the joined biological tissue. For example, measurements of the voltage difference delivered across the joined biological tissue and / or the current conducted by the joined biological tissue can be used to determine and / or control the actual power supplied to the joined tissue. This determined actual power can then be compared to the electrotherapy protocol. This comparison can be used to generate error signals. Measurements of electrical parameters can also be used to determine phase control criteria for controlling the phases of electrotherapy. Phase control criteria may include criteria for the start and end of a phase, as well as criteria for control within a phase.

[0067] Control circuit 48 is configured to control the operation of electrical energy source 44 and / or measuring circuit 46. Control circuit 48 is electrically connected to electrical energy source 44 and measuring circuit 46. Control circuit 48 causes electrical energy source 44 to provide electrotherapy signals to biological tissue coupled by electrically connected electrosurgical instruments 14'. Control circuit 48 causes electrical energy source 44 to generate electrotherapy signals according to an electrotherapy protocol, thereby controlling the generated electrotherapy signals for specific electrosurgical procedures.

[0068] Various electrotherapy schemes can be used to achieve various types of electrotherapy. For example, in some examples, the actual power (W) of the electrotherapy signal supplied to the joined biological tissue is controlled according to an electrical power scheme. In other examples, the voltage difference (V) of the electrotherapy signal delivered across the joined biological tissue is controlled according to a voltage scheme. In other examples, the current (A) of the electrotherapy signal conducted by the joined biological tissue is controlled according to a current scheme. In still other examples, the apparent power (VA) of the electrotherapy signal supplied to the joined biological tissue can be controlled according to a voltage-ampere scheme.

[0069] For example, control circuit 48 can supply energy from electrical energy source 44 to the joined biological tissue, thereby controlling the product of the voltage difference across the joined biological tissue and the current conducted by the joined biological tissue according to the electrotherapy protocol. Control circuit 48 can generate an error signal using a comparison of the determined actual power with the electrotherapy protocol. This error signal can be used in a closed-loop feedback system including electrical energy source 44 to generate an electrotherapy signal according to the electrotherapy protocol.

[0070] like Figure 2 As shown, the control circuit 48 includes a processor 54 and a memory 56. The control circuit 48 may include a timer and / or a clock. In some examples, the timer and / or clock is part of the processor 54. In other examples, the timer and / or clock is separate from the processor 54. In one example, the processor 54 is configured to implement functions and / or processing instructions for execution within the electrosurgical system 10. For example, the processor 54 may be able to receive and / or process instructions stored in the program memory 56P. The processor 54 can then execute the program instructions to cause the electrical energy source 44 to generate an electrotherapy signal according to a predetermined electrotherapy protocol. For example, the predetermined electrotherapy protocol can be retrieved from the data memory 56D. The processor 54 can compare electrical parameters measured by the measuring circuit 46 with the retrieved predetermined electrotherapy protocol. The processor 54 can send commands to the electrical energy source 44 and / or the measuring circuit 46. The processor 54 can also send or receive information from the user interface 50.

[0071] In various examples, it can be used Figure 2The components shown or various other components are used to implement the electrosurgical generator 12. For example, the processor 54 may include one or more of a microprocessor, control circuitry, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other equivalent discrete or integrated logic circuits.

[0072] Memory 56 can be configured to store information within the electrosurgical system 10 during operation. In some examples, memory 56 is described as a computer-readable storage medium. In some examples, the computer-readable storage medium may include a non-transitory medium. The term "non-transitory" can indicate that the storage medium is not implemented in a carrier wave or propagating signal. In some examples, a non-transitory storage medium may store data that can change over time (e.g., data stored in RAM or a cache). In some examples, memory 56 is temporary memory, meaning that the primary purpose of memory 56 is not long-term storage. In some examples, memory 56 is described as volatile memory, meaning that memory 56 does not retain its stored contents when the power to the electrosurgical system 10 is turned off. Examples of volatile memory may include random access memory (RAM), dynamic random access memory (DRAM), static random access memory (SRAM), and other forms of volatile memory. In some examples, memory 56 is used to store program instructions executed by processor 54. In one example, memory 56 is used by software or an application (e.g., a software program that implements electrical control of electrotherapy signals provided to biological tissues joined by electrosurgical instruments) running on the electrosurgical system 10 to temporarily store information, for example, in data memory 56D during program execution.

[0073] In some examples, memory 56 may also include one or more computer-readable storage media. Memory 56 may be configured to store a larger amount of information than volatile memory. Memory 56 may also be configured for long-term storage of information. In some examples, memory 56 includes non-volatile storage elements. Examples of such non-volatile storage elements may include magnetic hard disks, optical disks, flash memory, or electrically programmable memory (EPROM) or electrically erasable and programmable memory (EEPROM).

[0074] User interface 50 can be used to deliver information between electrosurgical system 10 and user (e.g., surgeon or technician). User interface 50 may include a communication module. User interface 50 may include various user input and output devices. For example, user interface may include various displays, sound signal generators, and switches, buttons, touch screens, mice, keyboards, etc.

[0075] In one example, user interface 50 utilizes a communication module to communicate with external devices via, for example, one or more wireless or wired networks, or both. The communication module may include, for example, a network interface card (NIC) with an Ethernet card, an optical transceiver, a radio frequency transceiver, or any other type of device capable of sending and receiving information. Other examples of such network interfaces may include Bluetooth, 3G, 4G, and Wi-Fi wireless computing devices, as well as Universal Serial Bus (USB) devices.

[0076] Figures 3A to 3B This is a flowchart of a non-limiting example of a method for generating electrotherapy signals for enclosing biological tissue joined by electrosurgical instruments. Figures 3A to 3B The method 100 shown can be used with, for example, Figures 1 to 2 This is used in conjunction with an electrosurgical system such as the electrosurgical system 10 depicted below. Using various techniques described below, the electrosurgical generator can control the energy delivery of the therapeutic signal to the biological tissue during a portion of the treatment phase based on incremental changes in energy delivery that vary with changes in the electrical parameters of the measured biological tissue. In some examples, the control circuitry can control the electrical power of the therapeutic signal delivered to the biological tissue during a portion of the treatment phase according to the treatment plan, for example, by controlling the power during the phase that provides tissue alteration.

[0077] For example, a control circuit can modify power incrementally based on current. In some examples, the function of current is a function of the change in current. This change in current can be a change in current during a pulse, and therefore looks more like a current value. In some examples, the function of current is a function of an instantaneous measurement of the change in current, and therefore looks more like the slope of a current function. The control circuit can modify power based on either current or an instantaneous change in current. In some examples, the function of the instantaneous measurement of the change in current is a linear function. In other examples, the control circuit can modify power incrementally based on resistance (e.g., when using controlled voltage techniques).

[0078] like Figure 4 As seen in some examples, the system can use a predetermined artificial power curve to control the electrical power of the therapeutic signal delivered to the biological tissue during a portion of the treatment phase. In some examples, the predetermined artificial power curve may include two or more linear portions.

[0079] It should be noted that Figure 3A and Figure 3B as well as Figure 4 These are non-restrictive specific examples used for illustrative purposes.

[0080] In some examples, the method can switch from using controlled power techniques to using controlled voltage techniques. In controlled voltage techniques, the current can be limited, but is allowed to move freely according to the response impedance, enabling variable power delivery. For example, the control circuitry can use controlled power techniques to deliver pulses, and the system can switch to controlled voltage techniques as resistance increases, approaches boiling, or reaches a threshold. In this way, the system can initially utilize controlled power techniques to deliver energy faster, but can switch to controlled voltage techniques for greater sensitivity as it approaches boiling. In some implementations using controlled voltage techniques, the system can use a predetermined voltage profile to control the electrical power of the therapeutic signal delivered to the biological tissue during a portion of the treatment phase. In some examples, the predetermined voltage profile may include two or more linear portions.

[0081] exist Figure 3A In this method, 100 begins at step 102, where, ( Figures 1 to 2 The electrosurgical system 10 (described in the image) is energized. Then, at step 104, the interrogation phase begins, during which ( Figure 2 The control circuit 48 (described in the text) causes (...) to (...) during the interrogation phase. Figure 2The electrical energy source 44 (described in the diagram) provides an interrogation signal, such as an interrogation pulse, to the tissue of the joined biological organism. The power (W) of the provided interrogation signal is controlled according to the interrogation protocol. In some examples, the power level provided to the joined biological tissue during the interrogation phase may be very low, resulting in little or no tissue effect. This low power level can be provided to obtain measurements of the electrical properties of the joined biological tissue. Such measurements are sometimes obtained before the application of electrotherapy to obtain pre-electrotherapy measurements. In some examples, the interrogation protocol instructs the provision of constant electrical power during the interrogation phase. This protocol may be referred to as a constant power protocol. In some examples, the control circuit 48 terminates the interrogation phase after a predetermined duration.

[0082] At step 106, controller 48 causes ( Figure 2 The measurement circuit 46 (described in the diagram) measures a first resistance of the joined biological tissue during the interrogation phase. The resistance measured during the first execution of step 106 is a reference resistance. Then, at step 108, the control circuit 48 compares the measured resistance with a previously measured minimum resistance (if any). At step 108, if the measured resistance is lower than the minimum resistance, the method proceeds to step 110, where the measured resistance is recorded as the new minimum value, and then the method proceeds to step 116 (at which point the first interval of the drying or baking phase begins). However, at step 108, if the measured resistance is greater than the minimum resistance, the method proceeds to step 112, where the control circuit 48 compares the measured resistance with the sum of the minimum resistance and a predetermined resistance increment. At step 112, if the measured resistance is less than the sum of the minimum resistance and the predetermined resistance increment, the method proceeds to step 114, where the measured resistance is ignored. However, at step 112, if the measured resistance is greater than the sum of the minimum resistance and the predetermined resistance increment, the method proceeds to... Figure 3B Step 146 is shown.

[0083] At step 116, for example at the site of tissue alteration, a first interval of the drying or baking phase begins, wherein control circuitry 48, during the first drying interval of the drying phase, causes electrical energy 44 to deliver a first drying signal, such as a first drying pulse, to the joined biological tissue. The power (W) of the provided first drying signal is controlled according to a first drying scheme or plan, for example using a predetermined power curve with a linear slope. In some examples, the first drying scheme or plan is, for example, in… Figure 4 The bottom curve shows a power scheme that monotonically increases between time t1 and t2.

[0084] Then, at step 118, the control circuit 48 compares the supplied power with a first threshold (e.g., a first predetermined maximum power). At step 118, if the supplied power is greater than the first predetermined maximum power, the method proceeds to... Figure 3B Step 130 shown, for example in Figure 4 The bottom curve plot shows the time interval between t2 and t3, which depicts the second drying interval of the drying stage. In some examples that include a second drying interval, the control circuit 48 can reduce the slope at block 130, for example, in... Figure 4 The bottom curve shows the time interval between t2 and t3. In this way, the control circuit 48 can modify the energy delivery during the first pulse (e.g., the first drying pulse) in response to (e.g., intermittently) a first electrical parameter of the joined biological tissue being measured to meet a first threshold.

[0085] This system can, for example, intermittently measure a first electrical parameter, such as current, and reduce or terminate energy delivery during a treatment phase in response to the measured current in the associated biological tissue satisfying a first threshold (e.g., a predetermined value). In some examples, the predetermined value is an absolute current threshold. In some examples, the predetermined value is a threshold that can change based on pulse count. In some examples, the predetermined value is the change in current relative to an initial current measurement. In some examples, the predetermined value is the change in current relative to a maximum current measurement during the pulse of the treatment signal.

[0086] However, at step 118, if the power supplied is less than the first predetermined maximum power, the method proceeds to step 120, at which point the control circuit 48 causes the measurement circuit 46 to measure a first electrical parameter, such as the impedance or current conducted by the joined biological tissue.

[0087] At step 122, the control circuit 48 compares the measured current (or impedance) for the pulse, such as a first electrical parameter, with a previously measured maximum current (if any), such as a threshold. At step 122, if the measured current is greater than the maximum current, the method proceeds to step 124, where the measured current is recorded as the new maximum value, and then the method returns to step 116 to continue the first drying interval of the drying phase by modifying the energy delivery during the first pulse. However, at step 122, if the measured current is less than the maximum current, the method proceeds to step 126, where the control circuit 48 compares the measured current with a predetermined fraction of the maximum current.

[0088] At step 126, if the measured current, such as a first measured current, is greater than a predetermined current threshold, such as a second measured current, the method returns to step 116 to continue the first drying interval of the drying phase. In some examples, the predetermined current threshold may be a ratio or fraction of the maximum current, such as 0.9, 0.8, 0.66, 0.5, and 0.4. In other words, control circuit 48 may continue drying signal or pulse in response to the ratio of the measured first current to the measured second current exceeding a predetermined factor indicating the absence of a liquid phase transition in the joined biological tissue. In other examples, the predetermined current threshold may be a difference rather than a ratio.

[0089] However, at step 126, if the measured current is less than a predetermined fraction of the maximum current, the method proceeds to step 128, at which point the first drying pulse of the first drying interval of the drying phase is terminated. The method then returns to step 104 to repeat the interrogation phase, after which the drying phase can be repeated or the closing phase can be initiated. In other words, the system can monitor the current during the treatment phase to determine when the treatment phase should end.

[0090] In some examples, and compared to determining at step 126 whether the measured current is less than a predetermined fraction of the maximum current, control circuit 48 may determine whether the measured current is less than a predetermined fraction (or offset) of the current value measured at a predetermined time interval after pulse initiation. For an impedance monitoring system, control circuit 48 may determine whether the measured impedance is greater than a predetermined fraction (or offset) of the resistance value measured at a predetermined time interval after pulse initiation.

[0091] exist( Figure 3B At step 130 (as depicted), the second interval of the drying stage begins, during which the control circuit 48 causes the electrical energy 44 to provide a second drying signal, such as a second drying pulse, to the joined biological tissue during the second drying interval of the drying stage. It should be noted that, although... Figure 3A and Figure 3B The diagram illustrates a first and second drying interval for the drying phase, but the second drying interval may not be necessary. Instead, in some examples, the drying phase may terminate during the first drying interval. The power (W) of the provided second drying signal (e.g., a second drying pulse) is controlled according to a second drying scheme or plan (e.g., using a predetermined power curve). In controlled power (or controlled voltage or controlled current) techniques, the system can control the setting of the actuation energy level. A power (or voltage or current) constraint refers to an upper limit or threshold that the controlled current cannot cross, otherwise an error state would exist.

[0092] In other examples, the voltage (V) across the conjoined biological tissue is controlled during a second drying interval. In controlled voltage techniques, the system can control the setting of the actuation energy level. Voltage constraint refers to an upper limit or threshold that the controlled voltage cannot cross, otherwise an erroneous state would occur. In controlled voltage implementations, the control circuitry can monitor the voltage of the treatment signal, and when a threshold or upper limit is reached, the control circuitry can maintain the voltage at the threshold. In some controlled voltage implementations, the voltage can be limited below the upper limit. In other controlled voltage implementations, the voltage can vary over time.

[0093] In the depicted example, the second drying interval uses a second drying scheme or plan as a monotonically increasing power scheme. In some examples, for example, the second drying scheme or plan is a linearly increasing power scheme. Then, at step 132, the control circuit 48 compares the supplied power with a second predetermined maximum power. At step 132, if the supplied power is greater than the second predetermined maximum power, the method proceeds to step 134, where the control circuit 48 causes the electrical energy source 44 to supply power equal to the second predetermined maximum power (e.g., a power upper limit), and then method 100 proceeds to step 136. However, at step 132, if the supplied power is less than the second predetermined maximum power, the method proceeds to step 136, where the control circuit 48 causes the measuring circuit 46 to measure the current conducted by the joined biological tissue.

[0094] At step 138, control circuit 48 compares the measured current with the previously measured maximum current. If, at step 138, the measured current is greater than the maximum current, the method proceeds to step 140, where the measured current is recorded as the new maximum value, and then the method returns to step 130 to continue the second drying stage. However, if, at step 138, the measured current is less than the maximum current, the method proceeds to step 142, where control circuit 48 compares the measured current with a predetermined fraction of the maximum current. At step 142, if the measured current is greater than a predetermined ratio or fraction of the maximum current, the method returns to step 130 to continue the second drying interval of the drying stage. In other words, control circuit 48 can reduce the drying signal or pulse in response to the ratio of the measured first current to the measured second current exceeding a predetermined factor, which indicates the phase transition of the liquid in the bonded biological tissue. In other examples, the predetermined current threshold may be a difference. However, at step 142, if the measured current is less than a predetermined fraction of the maximum current, the method can exit the second interval of the drying phase and return to step 104 to repeat the interrogation phase, after which the drying phase can be repeated or the sealing phase can begin. In other words, the system can monitor the current during the treatment phase to determine when the treatment phase should end.

[0095] At step 146, the sealing or solidification stage begins, at which point the control circuit 48 causes the electrical energy 44 to, for example, Figure 4 During the closure phase between times t7 and t8, as shown in the bottom graph, a closure signal, such as a closure pulse (e.g., a second pulse), is provided to the joined biological tissue. The power (W) of the provided closure signal (e.g., the closure pulse) is controlled according to a closure scheme or plan. In some examples, the closure scheme or plan is a monotonically increasing power scheme. Then, at step 148, the control circuit 48 compares the provided power with a third predetermined maximum power. It should be noted that this is an example of a predetermined power curve with exactly a constant power domain. At step 148, if the provided power is greater than the third predetermined maximum power, the method proceeds to step 150, where the control circuit 48 causes the electrical energy source 44 to provide power equal to the third predetermined maximum power, and then method 100 proceeds to step 152 to measure, for example, intermittently, a second parameter of the joined biological tissue (e.g., tissue resistance). However, at step 148, if the provided power is less than the third predetermined maximum power, the method proceeds to step 152, where the control circuit 48 causes the measuring circuit 46 to measure the resistance of the joined biological tissue.

[0096] At step 154, control circuit 48 compares the measured resistance with a second threshold, such as a calculated termination resistance value. In some examples, the calculated termination resistance value is based on a reference resistance (e.g., a first resistance) measured at step 106. For example, the termination resistance value could be a predetermined coefficient multiplied by the measured reference resistance. In some examples, the termination resistance value could be the sum of a predetermined resistance increment and the measured reference resistance or the minimum resistance measured during this or a previous stage. In some examples, the target resistance is a predetermined incremental resistance, where the predetermined incremental resistance is the change in resistance relative to the minimum resistance measurement during the pulse of the treatment signal.

[0097] At step 154, if the measured resistance is less than the calculated termination resistance, the method returns to step 146 to continue the closing phase. However, at step 154, if the measured resistance is greater than the calculated termination resistance, the closing phase terminates, and the method ends. In other words, in response to, for example, intermittently measured impedance satisfying a second threshold (e.g., changing a predetermined incremental impedance value), the method can, for example, modify the energy delivery of the second pulse by reducing or terminating the energy delivery of the treatment phase (e.g., the closing phase).

[0098] In some non-restrictive examples, Figure 3A and Figure 3BThe method shown can be implemented by a system such that a control circuit can monitor a first electrical parameter, such as current, in a first treatment phase, such as a drying phase, and reduce or terminate a first pulse based on the first electrical parameter, and monitor a second electrical parameter, such as impedance, in a second treatment phase, such as a sealing phase, and reduce or terminate a second pulse based on the second electrical parameter.

[0099] Figure 4 This is a diagram depicting a non-limiting example of an electrotherapy protocol or plan for controlling the electrical power supplied to a biological tissue being sealed. Figure 4 In the graph 200, there is a horizontal axis 202, vertical axes 204A to 204C, and functional relationships 206A to 206C. The horizontal axis 202 indicates time (seconds). The horizontal axis has times t0 to t8, which represent the transition times between the interrogation, drying, and sealing phases disclosed in the discussion of method 100 for generating electrotherapy signals for treating biological tissue joined by electrosurgical instruments. These phases—the interrogation phase, the first drying phase, and the sealing phase—are also marked at different locations in the graph 200. It should be noted that... Figure 4 The graphs are for illustrative purposes only. Figure 4 The graph depicts examples of responses, and different organizations can have different reactions.

[0100] Vertical axis 204A indicates the electrical power (W) supplied to the biological tissue joined by electrosurgical instruments. Functional relationship 206A indicates the relationship with... Figures 3A to 3B The non-limiting example of method 100 shown represents a non-limiting example of the power / time relationship corresponding to the electrotherapy signal generated. Vertical axis 204B indicates the current conducted by the joined biological tissue. Functional relationship 206B indicates the current / time relationship related to the current conducted by the joined biological tissue, to which the electrotherapy signal generated by method 100 is provided. Vertical axis 204C indicates the resistance of the joined biological tissue. Functional relationship 206C indicates the resistance / time relationship corresponding to the resistance of the joined biological tissue, to which the electrotherapy signal generated by method 100 is provided.

[0101] In some examples, the functional relationship 206A can be a predetermined power curve that includes an inquiry phase, a drying phase, and a closing phase. Figure 4In the specific non-limiting example shown, the drying phase depicts a first drying interval and a second drying interval. From time t0 to t1, the power / time relationship 206A indicates the interrogation phase. In some examples, the duration of the interrogation phase is as short as required to obtain a reference measurement of the bonded biological tissue. For example, the duration of the interrogation phase can be less than 1.0, 0.5, 0.25, or 0.1 seconds. As shown in graph 200, the interrogation phase is a constant power scheme or program with power P1 (W). From time t0 to t1, the current / time relationship 206B indicates a rapid current rise interrogation of the current conducted by the bonded biological tissue, followed by a current stabilization period, followed by a slight decrease. Because the power is controlled to be constant throughout the interrogation phase, the voltage applied across the bonded biological tissue is inversely proportional to the current / time relationship (in a multiplicative rather than additive sense). As the fluid temperature in the bonded biological tissue increases, the resistance of the tissue initially decreases. Since this is the first interrogation phase, the measured resistance is not less than the previously measured minimum resistance, and the method proceeds to the first drying phase.

[0102] From time t1 to t2, the power / time relationship 206A indicates the first interval of the drying stage. As shown in graph 200, the first drying interval of the drying stage is a power scheme or plan that monotonically increases from power P1 to P2 (W). From time t1 to t2, the current / time relationship 206B indicates the increase in current conducted by the bonded biological tissue throughout the first interval of the drying stage. Because the power is controlled throughout this first interval of the drying stage according to the drying scheme or plan, the product of the voltage applied across the bonded biological tissue and the current / time relationship should generate the power / time relationship 206A. Although not depicted, in some examples, the resistance / time relationship 206C may indicate that the resistance of the bonded biological tissue may initially decrease as the tissue warms up, but may subsequently increase as the tissue begins to dry during the first interval of the drying stage. This increased resistance may indicate the drying of the bonded biological tissue. Because the current does not decrease below a fraction of the previously measured maximum current before the power / time relationship 206A slopes to a predetermined threshold, the method proceeds to the second interval of the drying stage. If the current drops to a fraction below the previously measured maximum current during the first interval of the drying phase, then the second interval of the subsequent drying phase will be unnecessary (e.g., the second interval can be bypassed).

[0103] From time t2 to t3, the power / time relationship 206A indicates the second interval of the drying stage. As shown in graph 200, the second interval of the drying stage represents the electrical power scheme or plan that monotonically increases from power P2 to P3 (W). Using the information above... Figure 3A and Figure 3B The described technology, control circuit (e.g.) Figure 2The control circuit 48) can control the delivery of the therapeutic signal to the biological tissue during a portion of the treatment phase based on the incremental change in energy delivery as a function of the measured changes in the biological tissue's electrical parameters. For example, the control circuit can incrementally modify the power based on the current. In some examples, the function of the current is a function of the instantaneous measured change in the current. In some examples, the function of the instantaneous measured change in the current is a linear function. In other examples, the control circuit can incrementally modify the power based on the resistance.

[0104] From time t2 to t3, the current / time relationship 206B indicates that the current conducted by the bonded biological tissue increases at the beginning of the second interval of the drying phase, but peaks at the end of the second drying phase and then decreases. It should be noted that the second interval of the drying phase may not be necessary. In some examples, the power can be controlled throughout this second interval of the drying phase, such that the product of the voltage applied across the bonded biological tissue and the current / time relationship can generate a specific power / time relationship 206A.

[0105] In some examples, the second interval of the drying stage increases monotonically, but at a slower rate than the first interval of the drying stage. In other examples, the second interval of the drying stage increases linearly until the power supplied equals a predetermined maximum level, after which the power supplied remains constant. This is because the current decreases by ΔI1 (e.g., the measured current change (e.g.)). Figure 3A In box 126), the current becomes less than a predetermined fraction of the measured maximum current, causing the method to return to the interrogation phase, as shown at time t3. In other words, the current change ΔI1 causes the method to enter the interrogation phase at time t3. It should be noted that in Figure 4 In the non-limiting example shown, the current change ΔI1 that causes the method to enter the interrogation phase occurs after time t2. However, in other examples, the current change ΔI1 that causes the method to enter the interrogation phase may occur after time t1 during the first interval of the drying phase, and a second interval of the drying phase may not be necessary. However, if the current decrease ΔI1 is less than a predetermined fraction of the maximum measured current, the method will remain in the drying phase.

[0106] like Figure 4 As seen in some examples, the predefined power curve 206A may include two or more linear portions, such as the linear portions shown between t1 and t2 and between t2 and t3.

[0107] From time t3 to t4, the power / time relationship 206A again depicts the interrogation phase. As shown in graph 200, the interrogation phase is a constant power scheme for power P1 (W). Because the power is controlled to be constant throughout the interrogation phase, the voltage applied across the bound biological tissue is inversely proportional to the current / time relationship (in a multiplicative rather than additive sense). The resistance / time relationship 206C indicates that the resistance of the bound biological tissue decreases throughout the execution of the interrogation phase. The decrease in resistance may be due to fluid condensation in the tissue or fluid migration into the tissue. Because the measured resistance is no greater than the sum of the reference resistance and the predetermined incremental resistance, the method proceeds again to the first drying phase.

[0108] From time t4 to t5, the power / time relationship 206A indicates another first interval in the drying stage. The power / time relationship from time t4 to t5 is similar to the power / time relationship 206A from time t1 to t2, and will not be described in detail for the sake of brevity.

[0109] From time t5 to t6, the power / time relationship 206A indicates another second interval in the drying stage. The power / time relationship from time t5 to t6 is similar to the power / time relationship 206A from time t2 to t3, and will not be described in detail for the sake of brevity. Because the power is controlled to be constant throughout this second interval in the drying stage, the product of the voltage applied across the conjoined biological tissue and the current / time relationship should generate the power / time relationship 206A. This is because the decrease in current ΔI2 (e.g., the measured current change (e.g.)) Figure 3B If the value of box 142 in the diagram is less than a predetermined fraction of the maximum current being measured, the method returns to the query phase.

[0110] From time t6 to t7, the power / time relationship 206A indicates another inquiry phase. The power / time relationship from time t6 to t7 is similar to the power / time relationship 206A from time t3 to t4, and will not be described in detail for the sake of simplicity. Because the measured resistance is now greater than the sum of the reference resistance and the predetermined incremental resistance, the method proceeds to the closing phase.

[0111] From time t7 to t8, the power / time relationship 206A indicates the sealing phase. As shown in graph 200, the sealing phase is an electrical power scheme or plan that monotonically increases from power P1 to power P3 (W). From time t7 to t8, the current / time relationship 206B indicates the increase in current conducted by the bonded biological tissue throughout the sealing phase. The resistance / time relationship 206C indicates the increase in resistance of the bonded biological tissue during the execution of this sealing phase. The increased resistance may be due to drying the bonded biological tissue and thus sealing it. Because the measured resistance is now greater than the predetermined termination resistance, the sealing phase terminates, and the method ends.

[0112] Predictive phase control of electrotherapy signals ( Figures 5 to 6 )

[0113] Electrosurgical procedures can have one or more electrotherapy phases. For example, an electrosurgical tissue closure technique may have an inquiry phase, a drying phase, and / or a closure phase. During each of these electrotherapy phases, a corresponding electrotherapy signal, such as an inquiry signal, a heating signal, a drying signal, a cauterization signal, etc., can be provided to the biological tissue joined by the electrosurgical instrument. The electrotherapy signal provided to the joined biological tissue can be customized for the technique being performed and / or for a specific tissue. Therefore, each electrosurgical signal can be different for different procedures, different tissue types and numbers, and different electrotherapy phases. These differences in electrotherapy signals can be obtained using different electrotherapy protocols and / or different phase control criteria. Differences between different electrotherapy protocols may arise from differences in controlled electrical parameters and / or differences in phase control criteria. As mentioned above, differences in controlled electrical parameters include the apparent power (VA), actual power (W), voltage (V), and / or current (A) of the electrotherapy signal. Phase control criteria include criteria for phase start and phase end, as well as criteria for intra-phase control. Such phase control criteria include concurrent phase control criteria and predictive phase control criteria.

[0114] Synchronous phase control is performed by controlling the phases using real-time measurements. Predictive phase control is performed by generating future phase control criteria using reference measurements taken at a reference time. For example, tissue resistance measurements taken before or during the drying phase can be used to generate the duration of the drying phase. In some examples, tissue resistance measurements can be used to select one of several predetermined electrotherapy protocols. The selected protocol can then be used in subsequent electrotherapy phases.

[0115] For example, a reference measurement of tissue resistance can indicate the size of a blood vessel. Different electrotherapy protocols or plans and / or different stage control criteria can be used to heat blood vessels of different sizes. An appropriate electrotherapy protocol or plan tailored to the size of the blood vessel can achieve safer closure and reduce trauma to nearby tissues. To ensure proper closure of the joined blood vessel, the electrotherapy protocol can be customized based on the size of the blood vessel to be closed. The blood vessel size can be estimated based on a measured reference resistance of the joined blood vessel. The blood vessel closure can then be performed based on the electrotherapy protocol determined based on the measured reference resistance of the joined blood vessel.

[0116] The following is about Figure 6 Techniques for predicting and delivering energy based on the size of detected tissue are described, among others. In electrosurgical generators, for example... Figure 2 The electrosurgical generator 12 is connected via an electrosurgical device and a control circuit (e.g., Figure 2Control circuit 48) and measurement circuit (e.g. Figure 2 After the initial energy is applied to the biological tissue by the measurement circuit 46, the tissue impedance at this time can be measured or calculated in a timely manner. Then, the control circuit can determine the type of tissue (e.g., small or large blood vessels) in contact with the electrosurgical device, such as the one located between the jaws of the electrosurgical device, and then deliver energy to the detected tissue type.

[0117] Figure 6 This is a flowchart of a biovascular closure method that uses an electrical power scheme corresponding to the size of the biovascular vessel connected by an electrosurgical instrument. Figure 6 The method uses three treatment phases: Phase 1 is the inquiry phase, Phase 2 is the drying or baking phase, and Phase 3 is the vascular welding phase. In Phase 1, for example... Figure 1 The electrosurgical system 10 can perform error checks and, for example, generate an interrogation signal according to an interrogation protocol and deliver the interrogation signal to the joined tissue. Although in Figure 6 While described as controlled voltage, the control circuit can use controlled power techniques or controlled voltage techniques to deliver energy. In controlled voltage techniques, the current can be limited but allowed to move freely according to the response impedance, which enables variable power delivery.

[0118] Using the techniques disclosed herein, this method can begin, for example, phase 2, without the control circuitry having already determined which criterion will be used to terminate the phase. For example, as described in more detail below, the method begins phase 2, and the control and measurement circuitry can determine the impedance measurement of the tissue. In response, the control circuitry can determine whether to terminate phase 2 based on either a time measurement or an iterative impedance measurement. In this way, the control circuitry has two different criteria for how to terminate phase 2, but it is not necessary to have already selected which of these two criteria to use before entering phase 2.

[0119] At box 1900, stage 1 begins, and at box 1901, the control and measurement circuits can measure and / or calculate the initial impedance value R0 at time T0. At box 1902, the control circuit can set the voltage ramp rate (or slope) for stage 2. The voltage setting can be a constant voltage, an increasing voltage, or a decreasing voltage. Similarly, for controlled power implementations, the control circuit can set the power ramp rate (or slope) for stage 2. The power can be constant power, an increasing power, or a decreasing power. The output of stage 1 is the initial impedance value R0.

[0120] At box 1904, phase 2 begins. At box 1906, after a set time period, the control and measurement circuits can measure or calculate the reference impedance R1. The tissue's impedance can change from an initial impedance R0 to impedance R1. Impedance R1 is measured to determine whether phase 2 is an open-loop phase (based on a time criterion, such as terminating by a timer expiration) or a closed-loop phase (such as terminating based on an impedance criterion). For drier tissues, it is ideal to operate phase 2 as an open loop, while for wetter tissues, it is ideal to operate phase 2 as a closed loop.

[0121] At box 1908, the control circuitry can determine whether the impedance R1 is greater than or equal to the threshold impedance value Ra. In some examples, the impedance Ra can be an absolute impedance. In other examples, the impedance Ra can be an incremental value, such as a predetermined increase from the initial measured impedance R0. In some examples, the impedance Ra can be approximately 90 ohms.

[0122] In some examples, instead of comparing the measured impedance R1 with the threshold impedance Ra, or otherwise, the control circuit can compare other measured parameters with the threshold parameter. For example, the control circuit can compare the measured phase angle with the threshold phase angle. Examples of other parameters that can be used include, but are not limited to, the energy delivered over a period of time, current consumption, tissue temperature, etc.

[0123] If the control circuit determines that impedance R1 is greater than or equal to impedance Ra (the "Yes" branch of block 1908), the control circuit can operate phase 2 as an open loop at block 1910 and continue delivering power until the timer expires at time T2. At block 1912, phase 2 ends based on a time standard, such as according to time intervals.

[0124] However, if the control circuit determines that impedance R1 is not greater than or equal to impedance Ra (the "No" branch of block 1908), the control circuit can begin operating stage 2 as a closed loop at block 1914. At block 1916, the control circuit can measure impedance R2N at set time intervals. At block 1918, the control circuit can determine whether the current impedance measurement R2N is greater than or equal to the impedance threshold R2X.

[0125] If the control circuit determines that impedance R2N is not greater than or equal to impedance R2X (the "No" branch of box 1918), the method can continue applying power and return to box 1914. At box 1916, the method can repeat the impedance measurement at a defined time interval and determine at box 1918 whether the new impedance measurement is greater than or equal to a threshold. In this way, the method can continue applying power and iteratively compare the impedance measurement with the threshold impedance value.

[0126] If the control circuit determines that the impedance R2N (or any subsequent impedance measurement, if necessary) is greater than or equal to the impedance R2X (the “Yes” branch of box 1918), the control circuit can terminate stage 2 at box 1920 based on the impedance criterion (in contrast to the time criterion used for open-loop processing described above).

[0127] After the control circuit terminates stage 2, regardless of whether stage 2 terminates based on time or impedance measurement, the control circuit can calculate and store the impedance measurement value R3 at box 1922. Next, at box 1924, the control circuit can determine whether the current impedance measurement value R3 is less than or equal to the impedance threshold RX.

[0128] If the control circuit determines that impedance R3 is greater than or equal to impedance RX (the "Yes" branch of box 1924), then the tissue is a small vasculature, and the method can begin phase 3 at box 1926. At box 1928, the control circuit can operate phase 3 as an open loop and continue delivering electrical power until the timer expires at time T3. At box 1930, phase 3 ends based on the time interval.

[0129] However, if the control circuit determines that impedance R3 is not greater than or equal to impedance RX (the "No" branch of block 1924), then the tissue is a large vessel, and the method can begin phase 3 at block 1932, and the control circuit can operate phase 3 as a closed loop. At block 1934, the control circuit can measure impedance R3N at set time intervals. At block 1936, the control circuit can determine whether the current impedance measurement R3N is greater than or equal to the impedance threshold R3X.

[0130] If the control circuit determines that impedance R3N is not greater than or equal to impedance R3X (the "No" branch of box 1936), then at box 1938, the control circuit can determine whether the maximum time limit has been reached. If the control circuit determines that the maximum time limit has been reached (the "Yes" branch of box 1938), then the control circuit can terminate stage 3 at box 1940. In some examples, the time limit may be the time elapsed since the start of stage 1.

[0131] However, if the control circuit determines that the maximum time limit has not yet been reached (the "No" branch of block 1938), the control circuit can continue to apply power and return to block 1934. The method can then repeat the impedance measurement at time intervals at block 1934 and determine at block 1936 whether the new impedance measurement is greater than or equal to the threshold impedance value R3X. In this way, the method can continue to apply power and iteratively compare the impedance measurement with the threshold impedance value R3X.

[0132] If the control circuit determines that the impedance R3N is greater than the impedance R3X (the "Yes" branch of box 1936), then at box 1942, the control circuit can terminate stage 3 based on the impedance measurement (in contrast to the time standard for the open-loop processing used for the stage described above).

[0133] Correction of the measured resistance of conjoined biological tissues ( Figures 7A to 7B as well as Figure 9 )

[0134] The various electrical measurements described above can be used to determine electrotherapy protocols and / or phase control criteria. Therefore, accurate measurements contribute to generating electrotherapy signals that will successfully achieve their therapeutic objectives. The temperature of the electrosurgical instrument and the biological tissue to which it is attached affects the electrical measurements of the attached biological tissue. This temperature / measurement relationship introduces uncertainty and / or complexity when using such electrical measurements to determine electrotherapy protocols and / or phase control criteria. For example, comparing two electrical measurements taken on the attached tissue when the attached tissue and / or electrosurgical instrument are at different temperatures can be complex.

[0135] Some examples calibrate the electrical measurements of the joined tissue to account for the temperature of the electrosurgical instrument and / or the biological tissue. For example, the measured resistance of the biological tissue can be calibrated based on the actual temperature measurement of the electrosurgical instrument. In some examples, the electrosurgical instrument will be equipped with a temperature sensor in distal thermal communication with the joined biological tissue. In other examples, the measured resistance of the biological tissue can also be calibrated based on the temperature of the tissue and / or the electrosurgical instrument predicted according to various indirect measurements. For example, the measured tissue resistance can be calibrated based on the time interval between a reference time and a measurement time, during which electrical power has been delivered to the biological tissue. In some examples, the measured tissue resistance can be calibrated based on calculations of the energy supplied to the joined tissue prior to the electrical measurement.

[0136] Figure 7A It is a graph depicting the measured tissue resistivity as a function of the jaw temperature of the pliers. Figure 7A In the graph 400, there are horizontal axis 402, vertical axis 404, and resistance / temperature relationship 406. Horizontal axis 402 indicates the jaw temperature of the pliers. Vertical axis 404 indicates the temperature of the clamps held in the pliers (e.g., when clamped in the pliers). Figure 1 The forceps 14 depicts the measured resistance of tissue between the opposing jaw members. The resistance / temperature relationship 406 depicts the measured value of a specific biological tissue held by the opposing jaw members, which have been heated to various temperatures. The resistance / temperature relationship 406 depicts a monotonically decreasing function, where the measured resistance decreases with increasing jaw temperature. This change in measured resistance can be caused by many factors, including the dependence of resistance on tissue temperature, tissue-liquid phase, jaw-tissue interface, jaw temperature, etc.

[0137] This variation in measured tissue resistance introduces uncertainty and / or complexity when using such resistance measurements to determine electrotherapy protocols and / or stage control criteria. Some resistance dependencies are undesirable because they do not indicate therapeutic efficacy on biological tissues. Therefore, compensating for these undesirable dependencies can improve the quality of such resistance measurements. Various methods can be performed to compensate for electrical measurements of biological tissues to provide measurements that better indicate the therapeutic efficacy of electrotherapy.

[0138] Figure 7B It is a graph depicting the jaw temperature versus time after the termination power is applied. Figure 7B In the graph 410, the curves include a horizontal axis 412, a vertical axis 414, and a temperature-time relationship 416. The horizontal axis 412 indicates the time following the application of an electrotherapy signal to the biological tissue. During this post-treatment period, no power is delivered to the biological tissue. The vertical axis 414 indicates the measured temperature of the relative jaw members of the forceps used to apply the electrotherapy signal to the tissue. The temperature-time relationship 416 depicts the measured jaw temperatures at various post-treatment times. The temperature-time relationship 416 is a monotonically decreasing function of the time it takes for the temperature to asymptotically approach room temperature. This temperature-time relationship can be characterized by a time constant indicating the rate of decay.

[0139] The relationships depicted in graphs 400 and 410 can be used to model clamp temperature as a function of power application and the duration of power application. For example, the power dissipated by biological tissue joined by an electrosurgical instrument can be used to predict the temperature of that biological tissue, as well as the temperature of the junction of the electrosurgical instrument (e.g., Figure 1 The temperature of the relative jaw members 36 and 38 is depicted. This jaw temperature-power application relationship can be determined theoretically (e.g., using the tissue volume within the engagement of the relative jaw members) and empirically (e.g., by characterizing the instrument). In some examples, the position of the engaged jaw members can be used to determine, for example, the tissue volume within the engagement of the jaw members. In some examples, a combination of theoretical and empirical characterization can be used to model the relationship between jaw temperature and power application. The jaw temperature-time after treatment can be similarly characterized empirically and / or theoretically.

[0140] Furthermore, the undesirable resistance dependence, which does not indicate therapeutic efficacy on biological tissue, can be characterized empirically and / or theoretically. These different characteristics or models can then be combined to determine a compensating resistance value based on the measured resistance value. For example, tissue resistance measurements taken during the application of an electrotherapy signal to biological tissue can be compensated using a jaw temperature calculated based on the electrotherapy protocol. After the electrotherapy signal is applied to the biological tissue, the duration of post-treatment treatment can be used to compensate for the tissue resistance measurement.

[0141] Figure 8 It depicts the relationship between resistance compensation and time after power is applied. Figure 8 In the graph 420, the curves include a horizontal axis 422, a vertical axis 424, and an incremental resistance / time relationship 426. The horizontal axis 422 indicates the time after which an electrotherapy signal has been delivered to the biological tissue. During this post-treatment period, no power is delivered to the biological tissue. The vertical axis 424 indicates the incremental resistance required to compensate for the measured tissue resistance. In some examples, a multiplicative factor may be used instead of an additive incremental resistance correction. The incremental resistance / time relationship 426 depicts the incremental resistance correction factor required to compensate for the jaw temperature at various post-treatment times. The incremental resistance / time relationship 426 is a monotonically decreasing function of time asymptotically approaching zero.

[0142] In one example, the measured tissue resistance can be compensated when the electrosurgical instrument is hotter than a predetermined threshold, but not when the electrosurgical instrument is colder than a predetermined threshold. Figure 8 Operating areas 428 and 430 are depicted, defining two compensation mechanisms (e.g., hot and cold device mechanisms). Operating area 428 spans from the time immediately following the application of the electrotherapy signal to the biological tissue to a predetermined time after the application of the electrotherapy signal to the biological tissue. During the hot device mechanism, the measured tissue resistance is compensated by adding a predetermined incremental resistance value to the measured tissue resistance value. Figure 8 In the example depicted, the transition from a hot instrument mechanism to a cold instrument mechanism is defined as approximately 30 seconds after treatment. Compensation for tissue resistance measurements is not performed under the cold instrument mechanism.

[0143] Modification of initial impedance ( Figure 9 )

[0144] The control circuit of the electrosurgical generator (e.g.) Figure 2 The control circuit 48 of the electrosurgical generator 12 can use a predictive algorithm to generate an electrotherapy signal and deliver the electrotherapy signal to a device coupled to the electrosurgical device, such as... Figure 1 The biological tissue is located between the jaws of the forceps 14. The prediction algorithm may include multiple stages. For example, stage 1 may use low-power energy to initially access the vascular impedance and various energy delivery parameters. Based on the initial impedance determined in stage 1, the system can determine the size of the vascular tissue to be closed, set parameters in stage 2 to dry the vascular tissue, and provide an appropriate energy level and duration in stage 3 to close the vascular tissue.

[0145] However, accurately predicting vessel size can be challenging. For example, the initial vascular impedance that can be used to determine vessel size may be affected by the jaw temperature of the electrosurgical device. If the user attempts to close a second vessel immediately after closing the first, the jaw may be hot. High temperature can affect the initial vascular impedance measurement.

[0146] The inventors have recognized the need to reduce the temperature influence of initial impedance measurements and improve vessel size prediction. As described in more detail below, the inventors have recognized that in some examples, a temperature sensor coupled to the jaws can be used to determine the jaw temperature, and then a correction factor based on the jaw temperature can be used to modify the measured impedance. In other examples, the inventors have recognized that a correction factor based on one or both of the time elapsed since the previous activation or the electrical characteristics of the previous activation can be used to modify the measured impedance. Using the modified impedance value, the electrosurgical system can more accurately predict vessel size, which can be used to determine the settings of the electrosurgical generator.

[0147] Figure 9 This is a flowchart of a biological vascular occlusion method that can compensate for tissue impedance measurements after power application. At box 2000, control and measurement circuits, such as control circuit 48 and measurement circuit 46, are shown. Figure 2 Both of them can be measured in stage 1 to be attached to an electrosurgical device (e.g. Figure 1 The initial impedance R0 of the biological tissue in the forceps 14). At box 2002, the control and measurement circuits can measure the temperature of the forceps of the electrosurgical device using a temperature sensor coupled to the forceps in stage 1.

[0148] At box 2004, using the measured impedance and the measured jaw temperature, the control circuit can query a stored data log or dataset (e.g., a lookup table) and determine or select an adjusted or corrected impedance that takes into account the modification of the initial impedance R0 by the jaw temperature.

[0149] At box 2006, the control circuitry can determine the vessel size using a defined adjustable impedance. For example, using an algorithm or another stored dataset, the control circuitry can determine the vessel size using the adjusted impedance.

[0150] Then, at block 2008, the control circuitry can use the defined vessel size to determine various electrical parameters that define the electrosurgical signals that the electrosurgical generator will generate and deliver to the biological tissue of the vessel. In some examples, the vessel size can be defined as small or large vessels, and two electrosurgical signal settings corresponding to these two vessel sizes can exist. In other examples, a continuum of vessel sizes and electrosurgical settings corresponding to those vessel sizes can exist.

[0151] At block 2010, the control circuitry can use a defined signal setting to control the delivery of electrosurgical signals to the blood vessel to perform closure, and the method can end at block 2012.

[0152] As shown in box 2014, some examples can store the time elapsed since the last activation, instead of using the jaw temperature. The longer the time elapsed, the more the jaws cool down. In this way, the time elapsed since the last activation can be used as a proxy for the jaw temperature.

[0153] At box 2004, the control circuitry can determine the adjusted impedance using the measured initial impedance R0 and the time elapsed since the last activation. In some examples, the control circuitry can compare the elapsed time to, for example, a time T of 20 seconds, and if the elapsed time is greater than or equal to T, the control circuitry can use the initial impedance as the adjusted impedance. However, if the elapsed time is not greater than or equal to T, the control circuitry can add a compensation value to the initial impedance R0 to determine the adjusted impedance. For example, the compensation value can be between approximately 80 ohms and 90 ohms. It should be noted that the compensation value and the time T can depend on the design of the clamp.

[0154] In some examples, instead of adding a compensation value to determine the adjusted impedance, the control circuit can query a stored data log or dataset (e.g., a lookup table) and determine or select the adjusted impedance, i.e., taking into account the modification of the initial impedance R0 due to the time elapsed since the last activation.

[0155] After the control circuit determines the adjusted impedance, the method can proceed to block 2006 and beyond (as described above) to determine the vessel size, signal settings, and perform vessel closure.

[0156] In box 2014, in some examples, in addition to the time elapsed since the last activation, one or more electrical characteristics from the previous activation can be used. For example, the control circuitry can use the amount of energy or current from the previous activation to determine whether the previous activation generated a significant amount of heat on the jaws. If the activation is accidental or terminates quickly, little energy or current is delivered to the tissue, and therefore the jaws are not significantly heated.

[0157] In some examples, the control circuit can determine the amount of energy from a previously activated power curve by integrating the curve. In other examples, the control circuit can determine the amount of energy from a previously activated power curve by retrieving the applied time and the average power delivered from a stored dataset and multiplying the time by the average power delivered. Combining elapsed time information with energy or current information from a previously activated power curve can improve the accuracy of the initial impedance R0 measurement and enhance the system's ability to determine the pulse size. Elapsed time, temperature, and electrical characteristics (such as energy and current) can be collectively referred to as "closure parameters".

[0158] In some examples that use both elapsed time and electrical characteristics, if the electrical characteristic (e.g., energy or current) is below a threshold, the control circuit can use the initial impedance R0 as the adjusted impedance. If the electrical characteristic is not below the threshold, the method can use elapsed time to determine the adjusted impedance.

[0159] If the elapsed time exceeds the threshold, indicating that the jaws have cooled sufficiently, the control circuit can use the initial impedance R0 as the adjusted impedance. However, if the elapsed time does not exceed the threshold, the control circuit can add a compensation value of approximately 80 to 90 ohms to the initial impedance R0 to determine the adjusted impedance.

[0160] In some examples, instead of adding a compensation value to determine the adjusted impedance, the control circuit can query a stored data log or dataset (e.g., a lookup table) and determine or select the adjusted impedance, i.e., taking into account the time elapsed since the last activation and the modification of the electrical characteristics (e.g., energy or current) on the initial impedance R0.

[0161] After the control circuit determines the adjusted impedance, the method can proceed to block 2006 and beyond (as described above) to determine the vessel size, signal settings, and perform vessel closure.

[0162] In the example above, if the control system cannot explicitly determine the elapsed time (and electrical characteristics such as energy or current, if used), the control circuit can determine the adjusted impedance corresponding to the large pulse. The default setting for the large pulse can enhance the safety of pulse closure.

[0163] By using the above technology, the control circuit can deliver electrotherapy signals to biological tissue coupled with the electrosurgical device, measure the impedance of the coupled biological tissue, measure the closure parameters of the electrosurgical device, and determine the adjusted impedance based on the relationship between the closure parameters of the electrosurgical device and the measured impedance. Adhesion of the biological tissue to the electrosurgical instrument is reduced by pulsed electrical power of the electrotherapy signal. Figures 10A to 10D as well as Figure 11 )

[0164] Figures 10A to 10D This is a graph of the electrical parameters of the electrotherapy signal for an electrotherapy with a pulsed adhesion reduction component. Figure 10A In the graph 500, the curve includes a horizontal axis 502, a vertical axis 504, and a voltage / time relationship 506. The horizontal axis 502 indicates time. The vertical axis 504 indicates the voltage of the electrotherapy signal supplied to the tissue joined by the electrosurgical instrument. The voltage / time relationship 506 depicts the measurement of the voltage difference obtained at the time indicated by the horizontal axis 502. A voltage difference is applied across the tissue joined by the electrosurgical instrument. As shown in the graph 500, the voltage / time relationship has four phases 508A to 508D. The first phase 508A is the interrogation phase, during which a moderate voltage is supplied to the joined tissue to obtain an initial measurement of the tissue resistance.

[0165] Following inquiry stage 508A is the second stage 508B, which is the drying stage. During drying stage 508B, the voltage difference supplied across the joint tissue increases monotonically. In the depicted example, the voltage difference supplied across the joint tissue increases linearly. In some examples, drying stage 508B will have an initial slope larger than the final slope. In some examples, instead of controlling the voltage difference applied across the joint tissue during the drying stage, another electrical parameter is controlled. For example, in some examples, the current conducted through the joint tissue or the power supplied to the joint tissue (actual power or apparent power) is controlled.

[0166] Each of the controlled parameters offers various advantages and disadvantages compared to other controlled parameters. For example, controlling the voltage difference across the junctional tissue only requires measuring the voltage difference supplied across the junctional tissue. However, when the tissue is heated, its resistance typically increases, causing a decrease in the current flowing through it. Therefore, as the power supplied to the tissue decreases in response to the increased tissue resistance, the heating rate slows down.

[0167] Controlling the current conducted through the junctional tissue requires only measuring the current conducted through the junctional tissue, which can be easily done, for example, by measuring the voltage across a small series resistor. As mentioned above, heating of the tissue typically causes an increase in tissue resistance, thereby increasing the voltage difference across the tissue. Therefore, when the power supplied to the tissue increases in response to the increase in tissue resistance, the heating rate is accelerated.

[0168] However, controlling the actual power supplied to the junction tissue requires measuring both the voltage difference across the junction tissue and the current conducted through it. Depending on the electrotherapy protocol, as the tissue heats and its resistance changes, both the voltage applied across the junction tissue and the current conducted through it are adjusted to maintain power. The rate of heating is proportional to the power supplied to the junction tissue and is therefore controlled, for example, by the actual power (W) or current (I).

[0169] Following the drying stage 508B is the third stage 508C, which is the sealing stage. During the sealing stage 508C, the voltage difference applied across the joint tissue is constant. In some examples, the sealing stage 508C will not be constant. In some examples, instead of controlling the voltage difference applied across the joint tissue during the sealing stage, another electrical parameter is controlled.

[0170] Following the sealing phase 508C is the fourth phase 508D, which is the adhesion reduction phase. During the adhesion reduction phase, the voltage is pulsed between a maximum and a minimum voltage value. These pulses alternately heat the tissue and allow for cooling. The adhesion reduction program can have alternating minimum and maximum electrical power values, where each of the minimum electrical power values ​​is below a predetermined threshold configured to allow the temperature of the clamped biological tissue to drop below a liquid / gas phase transition threshold, allowing liquid to be present within the clamped biological tissue. In some examples, each of the minimum electrical power values ​​of the adhesion reduction program is maintained for a first predetermined duration. In some examples, the first predetermined duration is greater than or equal to 5 milliseconds. In some examples, the first predetermined duration is greater than or equal to 10 milliseconds. In some examples, the first predetermined duration is greater than or equal to 50 milliseconds.

[0171] During the cooling portion of the pulse waveform, fluid previously expelled from the junction can be returned to the junction. In the depicted example, the pulse waveform is periodic, where each cycle is identical to the previous cycle. In some examples, the pulse waveform is not periodic. For example, the maximum value of each pulse may be less than the maximum value of the previous pulse.

[0172] The adhesion reduction phase 508D can be initiated in various ways. The adhesion reduction phase begins after proper closure of the bonded tissue has been completed. In some examples, predictive phase control can be used to initiate or begin the adhesion reduction phase 508D. For example, tissue resistance can be measured at a reference time during the inquiry phase 508A, drying phase 508B, or closure phase 508C. The duration of the closure phase can be predicted based on the tissue resistance measured at the reference time. The adhesion reduction phase 508D can be initiated in response to the predicted duration of the closure phase having elapsed. In some examples, tissue treatment can continue during the adhesion reduction phase.

[0173] exist Figure 10BIn Figure 510, the graph includes a horizontal axis 512, a vertical axis 514, and a tissue resistance / time relationship 516. The horizontal axis 512 indicates time. The vertical axis 514 indicates the resistance of the tissue bonded by the electrosurgical instrument. The tissue resistance / time relationship 516 depicts the measurement of tissue resistance obtained at the time indicated by the horizontal axis 512. As shown in Figure 510, tissue resistance is low during the interrogation phase 508A, increases during the drying phase 508B, and remains high throughout the sealing phase 508C. During the adhesion reduction phase 508D, tissue resistance alternates between low and high values. The low measurement of tissue resistance obtained during the minimum of the pulse waveform indicates the return of fluid to the bonded tissue.

[0174] exist Figure 10C In the graph 520, the curve includes a horizontal axis 522, a vertical axis 524, and a current / time relationship 526. The horizontal axis 522 indicates time. The vertical axis 524 indicates the current conducted through the tissue joined by the electrosurgical instrument. The current / time relationship 526 depicts the measurement of the current obtained at the time indicated by the horizontal axis 522. As shown in the graph 520, the current increases at the beginning of the drying phase 508B, but then decreases at the end of the drying phase 508B as tissue resistance increases. The current then remains low throughout the sealing phase 508C. During the adhesion reduction phase 508D, the current is substantially periodic, with a maximum value greater than the current value obtained during the sealing phase 508C.

[0175] exist Figure 10D In the graph 530, the curve includes a horizontal axis 532, a vertical axis 534, and a power / time relationship 516. The horizontal axis 512 indicates time. The vertical axis 514 indicates the actual power supplied to the tissue by the electrosurgical instrument. The power / time relationship 516 depicts the measurement of the power supplied to the bonded tissue at the time indicated by the horizontal axis 532. As shown in the graph 530, the power increases at the beginning of the drying phase 508B, but then decreases at the end of the drying phase 508B as tissue resistance increases. During the adhesion reduction phase 508D, the power is substantially periodic, with a maximum value greater than the power value obtained during the sealing phase 508C. The power has a peak at the beginning of the maximum value. These peaks of the power peak correspond to the current peaks that occur before the fluid is expelled from the bonded tissue.

[0176] Figure 11 This is a flowchart of a method for reducing adhesion between biological tissue and electrosurgical instruments. Figure 11 In this method 540, the procedure begins at step 542, in which biological tissue is joined by an electrosurgical instrument. Then, in step 544, control circuit 48 ( Figure 2 The description in the text) enables electrical energy 44 ( Figure 2(As depicted in the text) During the interrogation phase, an interrogation signal is provided to the conjoined biological tissue. Then, in step 546, the control circuit 48 causes the measurement circuit 46 ( Figure 2 The measurement reference tissue resistance R (described in the text) REF Then in step 548, based on the measured reference resistance R... REF Determine the duration of treatment T THERAPY .

[0177] In step 550, control circuit 48 causes electrical energy 44 to deliver an electrotherapy signal to the bonded biological tissue during the electrotherapy phase. Then, in step 552, the elapsed treatment time T is recorded. ELAPSED The treatment duration T determined in step 548 THERAPY A comparison is made. In step 552, if the elapsed treatment time T... ELAPSED Less than the determined treatment duration T THERAPY Then the method returns to step 550, where an electrotherapy signal is provided to the joined biological tissue. However, in step 552, if the elapsed treatment time T... ELAPSED Greater than the determined treatment duration T THERAPY Then method 540 proceeds to step 554, where control circuit 48 causes electrical energy 44 to provide a pulsed adhesion reduction signal to the joined biological tissue during the adhesion reduction phase. After the adhesion reduction phase, the method terminates. The pulsed adhesion reduction signal can be determined according to an adhesion reduction scheme. An adhesion reduction scheme can be configured to reduce adhesion and, in some examples, simultaneously provide additional tissue treatment.

[0178] Determine whether a conductive foreign body is present in biological tissue joined by electrosurgical instruments. Figure 12 and Figure 13 )

[0179] During various surgical procedures, artificial devices are implanted into the patient's body. For example, broken bones can be secured using screws, bolts, washers, and other mechanical components. Anastomotic staples can be used to maintain the desired arrangement of tissue that has been processed during surgery. Pacemakers and other electronic devices can be implanted into the patient's body for various purposes. Many of these artificial devices are conductive elements or contain conductive elements. If a conductive object is found in tissue joined by electrosurgical instruments, the conductive object can interfere with the electrosurgical procedure.

[0180] Determining the environmental conditions of electrosurgical instruments (e.g., the presence of conductive foreign bodies within the host tissue before delivering the electrotherapy signal) can prevent undesirable tissue modification. The presence of conductive foreign bodies in the biological tissue joined by the electrosurgical instrument can be determined based on the angle of impedance measurements of the joined biological tissue. Therefore, inquiring about the angle of tissue impedance before the electrotherapy phase can prevent such undesirable tissue modification.

[0181] Figure 12 This is a graph depicting an example of the impedance angle / time relationship in biological tissue with and without metallic objects. Figure 12 In the graph 600, the curves include a horizontal axis 602, a vertical axis 604, and impedance angle / time relationships 606A to 606B. The horizontal axis 602 indicates time. The vertical axis 604 indicates the impedance angle of the biological tissue joined by the electrosurgical instrument. Impedance angle / time relationships 606A to 606B depict measurements of the impedance angle obtained at the time indicated by the horizontal axis 602 during the electrotherapy phase. The impedance angle of the biological tissue indicates the ratio of the reactive component of the tissue impedance to the resistive component of the tissue impedance. For example, an impedance angle of -90° indicates purely capacitive tissue impedance, a +90° impedance angle indicates purely inductive tissue impedance, and a 0° impedance angle indicates purely resistive tissue impedance. In some examples, the measured reference impedance angle is essentially equal to the angle difference between the voltage across the joined biological tissue and the conducted current, as measured by the measuring circuit.

[0182] Impedance angle / time relationship 606A corresponds to tissue in which there are no conductive foreign bodies. Impedance angle / time relationship 606B corresponds to tissue in which there are conductive foreign bodies. As shown in graph 600, impedance angle / time relationships 606A and 606B indicate changes in the impedance angle during the initial or transient portion of the electrotherapy phase, and then remain substantially constant during the final or steady-state portion of the electrotherapy phase. However, the steady-state values ​​of the impedance angle in impedance angle / time relationships 606A and 606B are different from each other. Impedance angle / time relationship 606A indicates an impedance angle θ. A The steady-state value, which is less than the impedance angle θ indicated by the impedance angle / time relationship 606B. B The steady-state value.

[0183] Impedance angle θ A With θ B Such differences can be used to determine the presence of conductive foreign bodies within tissue joined by electrosurgical instruments. For example, a predetermined threshold θ of the impedance angle can be used. THRESH Compare the measured impedance angle with that of the biological tissue. If the measured steady-state impedance angle is less than a predetermined angle threshold θ... THRESH (As in impedance angle / time relationship 606A), it can be determined that there is no conductive foreign object. However, if the measured steady-state impedance angle is greater than a predetermined angle threshold θ, then... THRESH (As in impedance angle / time relationship 606B), the presence of a conductive foreign object can be determined. In response, such as... Figure 2The control circuit 48 can generate an erroneous notification indicating the presence of a conductive foreign body in the joined biological tissue and reduce or terminate the delivery of the treatment signal. However, if a similar impedance is identified with a steady-state impedance angle not exceeding a predetermined threshold, the control circuit can continue to allow the delivery of the treatment signal. Energy can be applied and increased until boiling is detected. Due to the low resistance in this state, the current will be at the high end of its typical value until boiling begins.

[0184] In some examples, the impedance or resistance of the joined biological tissue is measured during the inquiry phase. If the measured impedance or resistance of the joined biological tissue is less than a predetermined resistance value, the phase angle of the impedance is determined and compared with a predetermined threshold θ. THRESH Compare them.

[0185] In some examples, if the measured steady-state impedance angle is less than a predetermined angle threshold θ THRESH (As in impedance angle / time relationship 606A), a circuit breakage can be determined. In response, the control circuit can generate an error notification indicating that the circuit is broken and can reduce or terminate the delivery of the treatment signal. In some examples, in response to a measured reference impedance angle being greater than a first angle (e.g., angle θA) and less than a second angle (e.g., angle θB), the control circuit can reduce the power level of the treatment signal. In some examples, the first angle may be approximately 70 degrees, which may be device-dependent.

[0186] In this way, the system can compare the measured reference impedance angle with a predetermined angle threshold θ. THRESH A comparison is made, and a response to environmental conditions of the indicating device is generated based on the comparison of the measured reference impedance angle with an angle threshold. The response may include a reduction in power and / or the generation of a signal indicating environmental conditions. The response may include, for example, a notification signal informing the user of the conditions.

[0187] Figure 13 This is a flowchart of a method for determining the presence of metallic objects in biological tissue joined by electrosurgical instruments. Figure 13 In method 620, the procedure begins at step 622, in which biological tissue is joined by an electrosurgical instrument. Then, in step 624, control circuit 48 ( Figure 2 The description in the text) enables electrical energy 44 ( Figure 2 (As depicted in the text) During the electrotherapy phase, an electrotherapy signal is delivered to the bonded biological tissue. Then, in step 626, the elapsed treatment time T is compared with a predetermined time threshold T at which steady-state tissue impedance has been reached. MEASURE A comparison is made. In step 626, if the elapsed treatment time T is less than the time threshold T... MEASURE If so, method 620 returns to step 624, and the electrotherapy protocol continues in step 624.

[0188] However, in step 626, if the elapsed treatment time T is greater than the time threshold T MEASURE Then method 620 proceeds to step 628, in which the control circuit 48 causes the measurement circuit 46 ( Figure 2 The impedance angle θ of the conjoined biological tissues (described in the text) is measured. MEAS Then, in step 630, the measured impedance angle θ of the joined biological tissue is... MEAS With the predetermined reference angle θ REF A comparison is made. In step 630, if the measured impedance angle θ MEAS Greater than the predetermined reference angle θ REF If the error persists, the control circuit can generate an error notification, and method 620 proceeds to step 632, where treatment is terminated. For example, the control circuit can generate an error notification indicating the presence of a conductive foreign body in the joined biological tissue.

[0189] In some examples, a reference angle within a predetermined range (e.g., θ) MIN <θ MEAS <θ MAX This can be used to determine whether a conductive foreign body is engaged by an electrosurgical instrument. However, in step 630, if the measured impedance angle θ MEAS Less than the predetermined reference angle θ REF If so, method 620 proceeds to step 634, where treatment continues.

[0190] The predetermined impedance angle that defines the boundary between the presence and absence of a conductive foreign body can vary depending on the specific electrosurgical instrument, the electrical parameters of the specific electrosurgical signal, the type of biological tissue, etc. For example, the frequency of the electrosurgical signal can be related to the impedance angle that defines the presence / absence threshold.

[0191] Short-circuit error capture using the band between the trigger value and the escape value ( Figure 14 )

[0192] As described above, electrosurgical generators (e.g., Figure 2 The electrosurgical generator 12) can coagulate or close blood vessels or otherwise modify tissue by applying electrical energy via an electrotherapy signal. One problem with such energy application is that if the electrodes coupled to or integrated with the electrosurgical device are short-circuited, the electrical energy passes primarily through the short-circuited area rather than through the tissue surrounding it. In such cases, the tissue is largely unaffected by the applied electrical energy.

[0193] In one approach, an insulating support can be used to prevent opposing electrodes from contacting each other and for energy to transfer through the contact point rather than through the tissue. However, conductive elements may be found during surgery that, when grasped by electrosurgical instruments, can create similar undesirable energy pathways. Examples of such elements include other surgical instruments, metal clips, and staples.

[0194] In some systems, electrosurgical generators can monitor specific (low) impedances (collectively referred to as impedances) and can notify users (e.g., surgeons or technicians) that such an unwanted energy path is currently occurring. If the electrosurgical generator determines the presence of such a low impedance, for example, it can start a timer and alert the user to the problem via audible and / or visual notifications.

[0195] Electrosurgical generators can include a delay before any notification of a low impedance to prevent other similar low impedance occurrences from mistakenly signaling a “real short circuit.” Other low impedances may occur due to, for example, saline added to the surgical site, highly conductive secretions (e.g., gallbladder bile), or thin, moist tissue (e.g., the omentum around the kidneys), especially when used with electrodes having a large electrical surface contact area.

[0196] When faced with such an environment, prolonged application of energy can enhance their electrical impedance by displacing the fluid or by converting it into a gas through a phase change. This is typically achieved, for example, over a set time period, or by advising the user to dry the tip of the electrosurgical instrument and / or grasp tissue in an alternative area. Therefore, when the cause is tissue-derived rather than a foreign body, it is preferable to obtain the desired modified tissue by continuing to apply energy during this initial short-circuit state.

[0197] During the application of energy in the initial short-circuit state of an organized source, impedance fluctuations may occur, where the impedance increases sufficiently to exceed the short-circuit trigger value, but remains in a situation where the applied power cannot overcome the low-impedance environment. In this case, instead of a fairly rapid short-circuit error (e.g., about 3 seconds), energy can be applied until other times are reached, such as the absence of organized effects or satisfaction of the maximum activation time error. However, this can prolong the process, potentially frustrating the user and resulting in a negative user experience. Applying a filter to this situation can only do so much; therefore, a more aggressive indicator that expels the low-impedance environment is more valuable.

[0198] The inventors have recognized the desirability of providing a system that indicates whether a short circuit in a low-impedance environment has been overcome or whether a small increase (followed by a decrease) in the ambient impedance has been achieved. These improvements may be particularly desirable in some systems, such as those where the ability to measure and act on impedance feedback is not very accurate. For example, a system may suffer from inaccuracy problems due to the low voltage applied during low-impedance conditions, making it impossible to obtain accurate impedance readings. This can lead to greater difficulties in detecting phase angle shifts caused by the inherent inductive nature of the system and the inductance generated by the material between the device jaws.

[0199] The inventors have recognized that two boundary thresholds can be used to provide an improved indication of whether a short circuit in a low-impedance environment has been overcome or whether a small increase (and subsequent decrease) in impedance has been achieved. As described in more detail below, the system can monitor two impedance values: a trigger value and an escape value. The system can use a first impedance value (“trigger” value) to trigger a short circuit, and the system can use a second impedance value (“escape” value) greater than the first impedance value to exit an erroneous clock timing routine.

[0200] The inventors have recognized that clinicians can locally boil a fluid, which may generate bubbles with resistance. At this point, the resistance increases significantly, potentially pushing the impedance reading above a first impedance value, but not necessarily out of the short-circuit state. The inventors have recognized that a second impedance value can be important because it ensures the system dries the tissue during the waiting time. By using the two-boundary threshold technique of this disclosure, the short-circuit state can be quickly communicated to the user, allowing the process to continue faster than with other techniques.

[0201] As mentioned above, Figure 2 Examples of surgical systems that can be used to implement various aspects of the two-boundary threshold technique of this disclosure are described. For example... Figure 1 As shown, Figure 1 The surgical system may include an electrosurgical device such as forceps 14. Forceps 14 may include two jaws, such as a first jaw member 36 and a second jaw member 38. In some examples, one of the two jaws may be movable, while the other jaw may be fixed. In other examples, both jaws may be movable.

[0202] It should be noted that the two-boundary thresholding technique of this disclosure is not limited to electrosurgical devices including clamps. Rather, the two-boundary thresholding technique can be implemented using devices such as scrapers and snares.

[0203] Electrosurgical devices (e.g., forceps 14) may include two or more electrodes, which are sized, shaped, and / or otherwise configured to deliver electrotherapy signals to biological tissue (e.g., Figure 1 (Organization 16). In some examples, the electrodes can be coupled with jaws (e.g., as shown in the image). Figure 1 The first jaw member 36 and the second jaw member 38 are integrated. In other examples, the electrodes may be coupled to the jaws.

[0204] Output circuit (e.g., including) Figure 2 The power supply 44) can be configured to generate electrosurgical energy and deliver the electrosurgical energy to the output terminal (e.g., Figure 2 The instrument interface 42 is used for delivery to the patient. The output terminal can be configured to couple to an electrosurgical device (e.g., an instrument interface 42). Figure 1 The clamps 14) and deliver electrosurgical energy (e.g., high frequency such as RF energy) to biological tissue via electrotherapy signals.

[0205] The control circuitry of the surgical system (e.g., Figure 1 The control circuitry 48 of the surgical system can be coupled to the output circuitry, and the control circuitry can be configured to perform various aspects of a two-boundary threshold technique. For example, a user, such as a surgeon or clinician, can initiate the continuous delivery of electrosurgical energy to a patient's biological tissue (e.g., tissue located between the two jaws of an electrosurgical device). In some examples, the processor (e.g., Figure 2 The processor 54 of the control circuit 48 can control the measurement circuit (e.g., Figure 2 Measurement circuit 46) to measure with electrosurgical equipment (e.g., Figure 1 The forceps 14) provides a first impedance value to the tissue through which the two electrodes are electrically connected. In some examples, the tissue may be positioned between the two electrodes of the electrosurgical device.

[0206] The processor can compare a measured first impedance value of the tissue with a first threshold (e.g., a trigger value). In a non-limiting example for illustrative purposes, the trigger value could be approximately 5 ohms. When the measured first impedance value is less than or equal to the first threshold, the processor (e.g., Figure 2 The processor 54 of the control circuit 48 can start, for example, a short-circuit timer included in the processor. In a non-limiting example for illustrative purposes, the timer's duration can be from about 3,000 milliseconds (ms) to about 6,000 ms.

[0207] The processor can control the measurement circuitry to measure a second impedance value of tissue positioned between two electrodes of an electrosurgical device. The processor can then compare this second measured impedance value of the tissue to a second threshold (e.g., an escape value), where the second threshold (escape value) is greater than a first threshold (trigger value). In a non-limiting example for illustrative purposes, the escape value could be approximately 10 ohms.

[0208] The trigger and escape values ​​represent typical values, but are not absolute and can depend on many factors, such as the impedance within the device, the exposed contact area, the processor's ability to measure impedance values ​​based on feedback, and other factors such as the cable length of the attached device. Trigger and escape values ​​can be tuned or adjusted for various systems. Additionally, the values ​​of the timer limits can be tuned or adjusted, and can depend on the manufacturer's understanding of the surgeon's perception and willingness to wait to see if a short-circuit error is indicated or to preferably apply power for a longer period (wait).

[0209] The surgical system can continue delivering electrosurgical energy when the second measured impedance value is less than the second threshold and the timer has not yet met its time limit. However, when the second measured impedance value is less than the second threshold and the timer has met its time limit, the control circuit can control the output circuit to reduce or terminate the delivery of electrosurgical energy. In some examples, the control circuit can increase the power or current limit, or both, for a short period of time to continue delivering energy to overcome a humid environment. In some examples, the surgical system can generate an instruction to the user when the timer has met its time limit. For example, the user interface (e.g., Figure 2 The user interface 50 of the surgical system can generate one or both of auditory and visual instructions to indicate that the delivery of electrosurgical energy has been reduced or terminated.

[0210] Energy delivery can occur during the inquiry phase, in which the amount of energy delivered is low, but not zero. For example, during the inquiry phase, the energy delivered may be insufficient to affect the tissue.

[0211] In some examples, the control circuitry can be configured to adjust at least one of a first threshold (trigger value), a second threshold (escape value), and a time limit based on at least one characteristic of the electrosurgical device. For example, current density can affect the amount of power of the delivered electrotherapy signal, which can affect the amount of energy delivered by the system to biological tissue. For example, the surface area of ​​the electrodes of the electrosurgical device can affect the current density. For example, for an electrosurgical device with a large surface area and a low-power electrosurgical generator, there may not be enough current to quickly burn off the fluid in the tissue. Therefore, it is desirable for the system to wait a longer period of time before reducing or terminating the delivery of energy to the tissue. For this purpose, the control circuitry can use the surface area of ​​the electrodes to adjust at least one of the first threshold (trigger value), the second threshold (escape value), and the time limit. For example, the control circuitry can retrieve various one or more parameters of the electrosurgical device stored in a memory device, one or more of which may include the surface area of ​​the electrodes associated with the electrosurgical device.

[0212] Furthermore, the jaw force of an electrosurgical device can affect the current density. For example, a stronger jaw force can increase the amount of tissue in contact with the electrode, which can affect the boiling point of the tissue. Thus, the control circuit can adjust at least one of a first threshold (trigger value), a second threshold (escape value), and a time limit for an electrosurgical device with a larger jaw force. Electrosurgical devices (e.g., Figure 1 The pliers 14 may include a jaw force sensor configured to sense jaw force, wherein the jaw force sensor is connected to a control circuit (e.g., Figure 2 48) Communication of the control circuit.

[0213] In addition to the characteristics of the electrosurgical device, at least one of the first threshold (trigger value), the second threshold (escape value), and the time limit can be surgery-related. For example, some surgeries and / or tissues are wetter than others. For instance, liver surgery may involve a large amount of blood from the liver. In some surgeries, clinicians may introduce large amounts of fluid to cleanse the tissue. Similarly, in some surgeries, it may be desirable for the system to wait a longer period before terminating energy delivery to the tissue. Therefore, in some examples, if necessary, the control circuitry can adjust at least one of the first threshold (trigger value), the second threshold (escape value), and the time limit to allow the electrosurgical generator additional time to burn off excess fluid.

[0214] Alternatively or additionally, characteristics of the electrosurgical device can be used to adjust thresholds or time limits. For example, the output current of the electrosurgical generator can affect the amount of power of the delivered electrotherapy signal, which can affect the amount of energy delivered by the system to biological tissue. In some examples, if desired, for example, control circuitry can adjust at least one of a first threshold (trigger value), a second threshold (escape value), and a time limit based on the output current to allow the electrosurgical generator additional time to burn off excess fluid.

[0215] In some examples, the two-boundary thresholding technique of this disclosure can be used during the initial tissue inquiry phase at the beginning of the process. In other examples, the technique can be used midway through the process (e.g., during the heating or drying phase).

[0216] For illustrative purposes, non-limiting examples of systems with and without escape values ​​will now be described. Initially, a clinician may press an activation button and attempt to deliver energy to an electrosurgical device, such as to the jaws. However, due to the high conductivity of saline and blood flushing on the electrosurgical device, the electrosurgical generator recognizes an impedance of 4 ohms, and a short-circuit timer begins.

[0217] For systems without an escape value, the electrosurgical generator can provide power and, at the 1000ms power application time, generate a bubble at, for example, the device jaws via a short-circuit timer, which increases the impedance to 6 ohms. The bubble is transient, but because the impedance is now above the 5-ohm threshold, the short-circuit timer is reset and the electrosurgical generator restarts its 3000ms countdown.

[0218] Transitional air bubbles can occur multiple times, but they can be repeatedly knocked out from the jaws, resetting the short-circuit timer each time, until, for example, between approximately 12,000 ms and approximately 30,000 ms, another alarm is eventually triggered, such as an extended start-up time alarm. Clinicians may be frustrated by this experience and realize that they must aspirate some or different portions of the surrounding saline to achieve a proper closure.

[0219] As described above, for systems without an escape value, the electrosurgical generator can provide energy and, at the 1,000 ms energy application time, generate a bubble at, for example, the device jaws via a short-circuit timer, which increases the impedance to 6 ohms. However, because an escape value of, for example, 10 ohms is required to exit the short-circuit loop, the short-circuit timer continues. Another bubble is generated, which again increases the impedance to 6 ohms, but this is again ignored by the short-circuit timer because the impedance has not yet met the escape value or upper boundary requirement. At 3,000 ms, a short-circuit alarm is presented to the clinician, who now knows that the fluid must be removed or the tissue must be gripped differently. This response is faster due to the 10-ohm upper boundary "escape" value, allowing the procedure to continue more quickly.

[0220] The two-boundary threshold technique described above can also be incorporated into other systems utilizing short-circuit triggers. For example, if a trigger value is met, the system can query feedback to determine and interpret the phase angle at that point in time while waiting to see if a short-circuit timer or escape value will be met first. If the phase angle is above a certain threshold, the system can determine that the frequency of the phase angle coupled with low impedance indicates that a metallic object was unintentionally (or otherwise) caught by the electrosurgical device. The system can continue monitoring the phase angle until the escape value is met or the short-circuit timer (e.g., 3,000 ms) is met.

[0221] Figure 14 This is a flowchart illustrating an example of the two-boundary technique described above. At box 1000, the processor (e.g., Figure 2 The processor 54 of the control circuit 48 can determine whether a short-circuit flag is set. If the short-circuit flag is not set (the "No" branch of block 1000), the processor can compare the measured impedance with a first impedance threshold (e.g., a 5-ohm threshold) at decision block 1002.

[0222] If the processor determines that the impedance is less than the first threshold (the "Yes" branch of box 1002), the processor resets the short-circuit timer and sets the short-circuit flag at box 1004, and can restart the sealing process at box 1006. If the processor determines that the impedance is not less than the first threshold (the "No" branch of box 1002), the processor resets the short-circuit timer and removes the short-circuit flag at box 1008, and can restart the sealing process at box 1006.

[0223] However, if the short-circuit flag is set (the "Yes" branch of box 1000), at decision box 1010, the processor can compare the measured impedance with a second impedance threshold (e.g., a 7-ohm threshold). If the processor determines that the impedance is not less than the second threshold (the "No" branch of box 1010), the processor resets the short-circuit timer and the short-circuit flag at box 1008, and can restart the closure at box 1006. If the processor determines that the impedance is less than the second threshold (the "Yes" branch of box 1010), at box 1012, the processor can compare the short-circuit timer with a timer limit (e.g., 3000ms).

[0224] If the processor determines that the short-circuit timer is greater than the timer limit (the "Yes" branch of box 1012), the processor can generate a short-circuit alarm (e.g., an audible and / or visual notification) at box 1014 to notify the user. If the processor determines that the short-circuit timer is not greater than the timer limit (the "No" branch of box 1012), the closure can be restarted at box 1006.

[0225] In this way, if the impedance is less than a first impedance threshold (e.g., 5 ohms), a short-circuit alarm can be generated for a duration defined by a short-circuit timer (e.g., 3000 ms), and the electrotherapy signal will decrease or terminate. A hysteresis may exist between the first and second impedance thresholds (e.g., 5 ohms and 7 ohms) such that a timer (e.g., with a 3000 ms timer limit) is activated when the impedance drops below the first threshold (e.g., 5 ohms) and resets when the measured impedance rises above the second threshold (e.g., 7 ohms).

[0226] Open-circuit check for impedance-limited endpoint waveforms Figure 15 and Figure 16 )

[0227] RF vascular occlusion devices typically use fixed maximum impedance values, such as those indicating that tissue has been adequately affected, or use impedance increments to detect when tissue has been adequately affected. Impedance can also be used to identify whether the instrument jaws have opened during activation. For example, the system may attempt to detect impedance above a set point to identify an "open circuit," indicating that the jaws are open.

[0228] However, in some cases, opening the jaws during activation can cause "false positives," where the generator signals a good seal, but in reality, the user has just opened the device jaws. For example, by using a system that monitors a "good seal" endpoint (e.g., 350 ohms) and an "open circuit" error value (e.g., 2000 ohms), the system can react to such false positives during activation. The user controls the energy applied to the tissue, and the system can monitor both the endpoint and the open circuit. In proper activation, energy application can initially decrease impedance, for example, from 30 ohms to 15 ohms, and then increase the tissue's impedance as the energy dries it. The energy increase can satisfy the 350-ohm endpoint value, and the generator can stop applying power and send a signal to the user indicating that sealing is complete.

[0229] In another example, the user controls the application of energy to the tissue, and this energy application initially reduces the tissue's impedance, for example, from 30 ohms to 15 ohms, and then the impedance begins to rise. During this rise, the user slowly (or quickly) opens the jaws. The impedance value can increase rapidly, first passing the required 350-ohm boundary, at which point the system shuts off the power and reports a good seal. Because the energy is turned off (and if a tissue greater than 350 ohms were produced, continuing to apply energy would result in a "tissue-jaw adhesion" situation) and the impedance will not reach the 2000-ohm "open circuit" error value, the system incorrectly reports a good seal.

[0230] The inventors have recognized the need to include an open-circuit check, which begins when a user initiates continuous electrosurgical energy delivery to biological tissue by starting a timer. When the timer reaches its limit (or "timeout"), the system can determine an impedance value and whether that impedance value indicates an open circuit. If the impedance value does indicate an open circuit, the system can reduce or terminate energy delivery, and if the impedance value does not indicate an open circuit, the system can allow energy to continue being applied until the impedance meets an endpoint value.

[0231] Using the proposed timer technique, an electrosurgical generator (e.g., Figure 2 The electrosurgical generator 12) can apply energy to the system and interact with electrosurgical devices (e.g., Figure 1 The biological tissue is contacted between the jaws of the forceps 14. When the control circuit has determined that the tissue is ready to be driven to the final impedance endpoint value or impedance increment value, the processor (e.g., Figure 2 The control circuit 48 and the processor 54) system can set timers, for example, from 50ms to 100ms.

[0232] When the timer "times out", the measurement circuit (e.g., Figure 2The measurement circuit 46) measures the impedance value. The processor can determine whether the measured impedance indicates an open circuit and energy delivery should be reduced or terminated, or whether the measured impedance is below the open circuit value and energy delivery can continue until the impedance meets the required endpoint value. By using these techniques, there exists a minimum time period during which neither the endpoint value nor the open circuit value can be achieved, but depending on the impedance measured at the end of that time period, the processor can decide whether to mark an "open circuit" error and reduce or terminate energy delivery or continue energy delivery to the full closed-cycle endpoint impedance value.

[0233] Several possible scenarios that may occur when using open-circuit testing techniques will now be described. In the first scenario, the user applies energy to tissue, for example, between the jaws of an electrosurgical device, and the tissue's impedance decreases and then increases. The processor can recognize that the tissue has been appropriately affected and can then start a timer. After a time limit (e.g., 50 ms), the impedance is below the "open circuit" value (e.g., the absolute value of 2000 ohms or the impedance increment), but also below the target tissue endpoint value (or the impedance increment). Thus, the processor continues to control the application of power until the target endpoint value is reached. The processor terminates the application of power and indicates to the user that a good closure has been achieved.

[0234] In some examples, the rate of change of impedance can be a trigger variable. For example, if the rate of change of impedance exceeds a preset value, the generator can report an open circuit and then modify the energy output (or terminate or significantly reduce it).

[0235] In the second scenario, the user applies energy to tissue, for example, between the jaws of an electrosurgical device, and the tissue's impedance decreases and then increases. The processor can recognize that the tissue has been appropriately affected and can start a timer. After a time limit (e.g., 50 ms), the impedance falls below an "open circuit" value (e.g., the absolute value of 2000 ohms or the impedance increment), but the tissue is at or above a tissue endpoint value (e.g., 350 ohms). The processor terminates the application of power and indicates to the user that a good closure has been achieved.

[0236] In the third case, the user applies energy to the tissue, for example, between the jaws of an electrosurgical device, and the tissue's impedance decreases and then increases.

[0237] The processor can recognize that the tissue has been appropriately affected and can then start a timer. The user prematurely releases the tissue, for example by opening the device jaws, and the impedance rapidly increases through the endpoint value and then through the open circuit value (e.g., the absolute value of 2000 ohms or the impedance increment). For example, after 50ms, the processor can determine that the impedance exceeds the open circuit value, terminate the application of power, and indicate an incomplete closure "open circuit" error message to the user.

[0238] The duration of the timer can be important for successfully identifying open circuits and proper closure. If the duration is too long, for example when a user attempts to affect a thin fascia material on the pelvic wall, a small amount of tissue can quickly reach an impedance value greater than the open circuit value. Although such tissue is usually very conductive initially, fluid contents can boil rapidly, and the impedance of a portion of such a thin material, such as within the jaws of a device, causes a rapid rise in impedance. For example, if the timer duration is 200 ms, proper closure or tissue modification of the thin fascia material on the pelvic wall will result in an error message instead of the proper good closure normal state.

[0239] If the timer is too short, false positives may occur. For example, if the timer is set to 10ms, the following may happen: The user applies energy to the tissue, and the impedance decreases and then increases. When the impedance increases, the processor determines that the tissue is ready to be driven to the endpoint and starts the timer. If the jaws open slowly, the impedance slope of the jaws will not meet the open-circuit value within 10ms, and therefore the control circuitry continues to apply energy. For example, as the impedance continues toward the 2000-ohm open-circuit value, the impedance value passes through the 350-ohm endpoint value and stops applying power, thus incorrectly giving a properly closed state at the end.

[0240] The values ​​of the timer, endpoint impedance, and open-circuit impedance can depend on many factors, such as the following factors (alone or in combination): 1) the amount of power applied to the tissue at that time (which can be the set power or the power considered and the timer and / or impedance values ​​adjusted accordingly); 2) the target tissue (previous power feedback can provide an indication of the type of tissue between the jaws and predict the possible or expected impedance slope and adjust the timer and / or impedance values ​​accordingly); and 3) the surface area of ​​the electrodes and / or the force applied by the electrode jaws in their fully closed position.

[0241] Using the open-circuit inspection technique described in more detail below, when preparing to drive tissue to (closed) endpoint values, the electrosurgical system (e.g., Figure 2 System 10) can be configured with a timer, for example, from 50 ms to 100 ms. When the timer reaches its limit and "times out," the system can measure the impedance (or the rate of change of impedance over time) and determine whether the value indicates an open-circuit condition or whether it is permissible to continue applying energy until the impedance meets the endpoint value indicating a well-closed circuit. In this way, there exists a minimum time period during which neither the endpoint value nor the open-circuit value can be achieved. However, based on the impedance determined at the end of the timer, the system can determine whether to continue with the full closure cycle endpoint value or whether an open circuit is indicated.

[0242] Figure 15This is a flowchart depicting an example of the above-mentioned open-circuit examination technique that can be used in a surgical system. For example... Figure 1 As shown, Figure 1 The surgical system may include an electrosurgical device such as forceps 14. Forceps 14 may include two jaws, such as a first jaw member 36 and a second jaw member 38. In some examples, one of the two jaws may be movable, while the other jaw may be fixed. In other examples, both jaws may be movable.

[0243] It should be noted that the open-circuit inspection techniques described in this disclosure are not limited to electrosurgical devices including clamps. Rather, open-circuit techniques can be achieved using devices such as scrapers and snares.

[0244] Electrosurgical devices (e.g., forceps 14) may include two or more electrodes, which are sized, shaped, and / or otherwise configured to deliver electrotherapy signals to biological tissue (e.g., Figure 1 (Organization 16). In some examples, the electrodes can be coupled with jaws (e.g., as shown in the image). Figure 1 The first jaw member 36 and the second jaw member 38 are integrated. In other examples, the electrodes may be coupled to the jaws.

[0245] Output circuit (e.g., including) Figure 2 The power supply 44) can be configured to generate electrosurgical energy and deliver the electrosurgical energy to the output terminal (e.g., Figure 2 The instrument interface 42) is used for delivery to the patient. The output terminal can be configured to couple to an electrosurgical device (e.g., Figure 1 The forceps 14), and deliver electrosurgical energy (e.g., high frequency such as RF energy) to the biological tissue via electrotherapy signals. The control circuitry of the surgical system (e.g., Figure 1 The control circuit 48) of the surgical system can be coupled to the output circuit, and the control circuit can be configured to perform various aspects of the open-circuit inspection technique.

[0246] Now refer to Figure 15 At box 1100, for example, when a user, such as a surgeon or clinician, initiates the continuous delivery of electrosurgical energy to biological tissue positioned between two electrodes of an electrosurgical device, the control circuitry may activate a timer. In some examples, the timer may be included in the processor (e.g., Figure 2 In the processor 54). In some examples, the control circuitry can set a timer when it has determined that the tissue is ready to be driven to the final impedance endpoint value (or impedance increment value). In some examples, the processor (e.g., Figure 2 The processor 54 of the control circuit 48 can control the measurement circuit (e.g., Figure 2The measurement circuit 46) is used to measure the location of the electrosurgical device (e.g., Figure 1 The impedance value of the tissue between the two electrodes of the clamp 14).

[0247] At box 1102, the processor can determine whether the timer exceeds a timer limit (e.g., 50 ms to 100 ms). If the timer has not exceeded the time limit (the "No" branch of box 1102), the system can continue the delivery of electrosurgical energy at box 1104. If the timer has met the time limit (the "Yes" branch of box 1102), at box 1106, the processor can compare the measured impedance representation with a first threshold (endpoint value) (e.g., 250 ohms to 350 ohms). The first threshold can be stored in memory (e.g., ...). Figure 2 In the memory of 56).

[0248] At box 1108, if the processor determines that the representation of the measured impedance is less than a first threshold (the "Yes" branch of box 1108) (endpoint value), the processor can continue the delivery of electrosurgical energy. If the processor determines that the representation of the measured impedance is not less than the first threshold (the "No" branch of box 1108), then at box 1110, the processor can compare the representation of the measured impedance with a second threshold (open-circuit value) (e.g., 2000 ohms). The second threshold can be stored in memory (e.g., ...). Figure 2 In the memory of 56).

[0249] If the processor determines that the measured impedance is less than a second threshold (the "Yes" branch of box 1110), then at box 1112, the processor can reduce or terminate the delivery of electrosurgical energy. Here, the measured impedance is greater than a first threshold (endpoint value) and less than a second threshold (open circuit value), indicating that good closure has been achieved. In some examples, the control circuitry may generate a notification to the user to indicate good closure.

[0250] If the processor determines that the representation of the measured impedance is not less than a second threshold (the "No" branch of box 1110), then at box 1114, the processor can reduce or terminate the delivery of electrosurgical energy. Here, the measured impedance is greater than a first threshold (endpoint value) and also equal to or greater than a second threshold (open circuit value), indicating the presence of an open circuit. In some examples, the surgical system may generate an indication to the user to indicate an open circuit. For example, a user interface (e.g., Figure 2 The user interface 50 of the surgical system can generate one or both of auditory and visual indications to indicate that the delivery of electrosurgical energy has been reduced or terminated and that an open circuit has been detected.

[0251] As mentioned above, in some examples, the processor (e.g., Figure 2The processor 54 of the control circuit 48 can control the measurement circuit (e.g., Figure 2 The measurement circuit 46) measures the impedance value of the tissue, and the processor can determine whether the representation of the measured impedance exceeds a threshold. In some examples, the representation of impedance includes the value of the impedance, such as the absolute value of the impedance. In other examples, the representation of impedance includes the change in the value of the impedance (or "increment") with respect to time, such as the first derivative of the impedance with respect to time.

[0252] Figure 5 This is a flowchart illustrating another example of the above-described open-circuit inspection technique that can be used in a surgical system. In method 300, at block 302, the control circuit can start a timer at the beginning of stage 3. At block 304, the control circuit can apply electrosurgical energy to the biological tissue positioned between the two electrodes of the electrosurgical device. At block 306, the control circuit can determine whether the endpoint is satisfied. If the control circuit determines that the endpoint has not been satisfied (the "No" branch of block 306), the control circuit can return to block 304 and continue applying electrosurgical energy to the biological tissue. However, if the control circuit determines that the endpoint has been satisfied (the "Yes" branch of block 306), the method proceeds to block 308.

[0253] At block 308, the control circuit can determine whether the elapsed time is less than or equal to a timer limit. If the control circuit determines that the elapsed time is less than or equal to the timer limit (the "Yes" branch of block 308), the control circuit can reduce the delivery of electrosurgical energy and indicate an open circuit at block 310. If the control circuit determines that the elapsed time is not less than or equal to the timer limit (the "No" branch of block 308), the control circuit can reduce the delivery of electrosurgical energy and indicate the presence of a good seal at block 312.

[0254] Figure 16 This is a flowchart illustrating another example of the aforementioned open-circuit examination technique that can be used in surgical systems. Figure 16 Similar to Figure 15 The difference is: in Figure 16 The control circuit can compare the rate of change of impedance with respect to biological tissue over time (e.g., 40 kilohms per second) with a threshold.

[0255] Now refer to Figure 16 At box 1200, the control circuitry can activate a timer in response to the delivery of electrosurgical energy to biological tissue positioned between two electrodes of an electrosurgical device. In some examples, the timer may be included in a processor (e.g., Figure 2 In the processor 54). In some examples, the control circuitry can set a timer when it has determined that the tissue is ready to be driven to the final impedance endpoint value (or impedance increment value). In some examples, the processor (e.g., Figure 2 The processor 54 of the control circuit 48 can control the measurement circuit (e.g., Figure 2 The measurement circuit 46) is used to measure the location of the electrosurgical device (e.g., Figure 1 The impedance value of the tissue between the two electrodes of the clamp 14).

[0256] At box 1202, the processor can determine whether the timer exceeds a timer limit (e.g., 50 ms to 100 ms). If the timer has not exceeded the time limit (the "No" branch of box 1202), then at box 1204, the system can continue the delivery of electrosurgical energy. If the timer has met the time limit (the "Yes" branch of box 1202), then at box 1206, the processor can compare the rate of change of the measured impedance relative to time with a first threshold (endpoint value). The first threshold can be stored in memory (e.g., ...). Figure 2 In the memory (56). A non-limiting example of the rate could be 2000 ohms or 40,000 ohms / second over a 50ms time period.

[0257] At box 1208, if the processor determines that the rate of change of the measured impedance is less than a first threshold (the "Yes" branch of box 1208) (endpoint value), then at box 1204, the processor can continue the delivery of electrosurgical energy. If the processor determines that the rate of change of the measured impedance is not less than the first threshold (the "No" branch of box 1208), then at box 1210, the processor can compare the rate of change of the measured impedance with a second threshold (open-circuit value). The second threshold can be stored in memory (e.g., ...). Figure 2 In the memory of 56).

[0258] If the processor determines that the rate of change of the measured impedance is less than a second threshold (the "Yes" branch of box 1210), then at box 1212, the processor can reduce or terminate the delivery of electrosurgical energy. Here, a rate of change greater than a first threshold (endpoint value) and less than a second threshold (open circuit value) indicates that good closure has been achieved. In some examples, the control circuitry may generate a notification to the user to indicate good closure.

[0259] If the processor determines that the rate of change of the measured impedance is not less than a second threshold (the "No" branch of box 1210), then at box 1214, the processor can reduce or terminate the delivery of electrosurgical energy. Here, a rate of change greater than a first threshold (endpoint value) and also equal to or greater than a second threshold (open circuit value) indicates the presence of an open circuit. In some examples, the surgical system may generate an indication to the user to indicate an open circuit. For example, a user interface (e.g., Figure 2The user interface 50 of the surgical system can generate one or both of auditory and visual indications to indicate that the delivery of electrosurgical energy has been terminated and an open circuit has been detected.

[0260] By using the open-circuit checking techniques described above, the system can provide a better closure indication with fewer errors.

[0261] Alternating power correction output in low-precision hardware systems ( Figure 17 )

[0262] Electrosurgical generators continue to evolve with new, state-of-the-art hardware that enables them to be more precise and responsive to feedback from the tissue they are intended to alter. Improvements in hardware architecture can offer numerous benefits over their less advanced or historical counterparts, such as higher CPU speeds, which allow for faster responses in collecting, analyzing, and reacting to data, and new capabilities that enable phase angle calculations, which can provide more accurate indications of feedback-based data such as power delivery and impedance.

[0263] The common expectation is to leverage existing hardware already in the hospital to achieve the performance of new, "state-of-the-art" hardware, thus utilizing older assets without having to upgrade to new ones to provide the same performance to the user. Such performance improvements can be important in some electrosurgical applications to ensure optimal tissue modification performance for the patient.

[0264] For example, appropriate power delivery is important for providing optimal tissue performance in vascular closure. Delivering too much energy too quickly can cause tissue damage due to the vapor bag within the tissue. Applying energy slowly can significantly prolong the procedure and result in prolonged anesthesia, potentially leading to reduced benefits from the procedure and a higher risk of complications in patient recovery. From a competitive standpoint, rapid tissue modification with a high confidence level of accurate tissue effect as a result is important for devices available on the market.

[0265] Many older electrosurgical systems may not have the capability to accurately measure the phase angle of the RF output. During the closure process, changes in the tissue clamped between the jaws and its interaction with the inherent inductance and capacitance in the output circuitry can cause a change in the phase angle of the RF waveform. Without considering this phase angle, calculations of power and load resistance may be inaccurate, and therefore measuring this parameter can increase the system's accuracy.

[0266] When voltage (“E”) leads current (“I”), the mnemonic “ELI” helps to remember that the load is considered inductive. When current (“I”) leads voltage (“E”), the mnemonic “ICE” helps to remember that the load is considered capacitive. In the “ELI” or “ICE” case, due to the misalignment of the current and voltage peaks, the resulting phase angle shift results in a reduction in actual power delivery compared to the apparent power delivery that the electrosurgical generator believes it is providing.

[0267] The accuracy of the applied voltage further complicates the problem. As voltage decreases, achieving accurate voltage application in older systems can become difficult, especially when a voltage has already been generated to control high rates intended for a single-pole output (e.g., 4000V or higher) and then applied to a bipolar output that can be as low as tens of volts or less. This can lead hardware manufacturers to create “tuned hardware,” which is designed to achieve accuracy over a specific impedance and voltage range, typically requiring the device to operate with the desired phase shift. In the lower impedance range, the accuracy of calculated power delivery can become extremely difficult due to the very low voltage levels.

[0268] As an example, to supply a specific power (e.g., 100W), the system supplies a current (I) at a voltage (V) to meet the power requirement. Impedance determines the composition of the voltage and current used to deliver the required power. For example, if the impedance is 5 ohms, an electrosurgical generator can provide a 4.5A output of 22.22V.

[0269] As another example, if the same system attempts to deliver 30W (31.25W) to an impedance of 5 ohms, the electrosurgical generator can provide an output of approximately 2.5A at 12.5V. Consider this 12.5V output on systems configured to provide up to 4000V in some cases. Older electrosurgical systems, whose impedance range often becomes less accurate, typically range from approximately 0 ohms to 50 ohms. For such an impedance range, older electrosurgical systems may struggle to apply sufficient current to burn off the fluid in the tissue to provide a good seal because the power output of the electrosurgical generator is not precise enough.

[0270] The inventors have recognized the need to improve power control in conventional electrosurgical systems. To address this need, the inventors have realized that applying power correction at lower impedance values ​​can improve power control in conventional electrosurgical systems and overcome their lack of accuracy.

[0271] like Figure 1 As shown, Figure 1The surgical system may include an electrosurgical device such as forceps 14. Forceps 14 may include two jaws, such as a first jaw member 36 and a second jaw member 38. In some examples, one of the two jaws may be movable, while the other jaw may be fixed. In other examples, both jaws may be movable.

[0272] It should be noted that the power correction techniques described in this disclosure are not limited to electrosurgical devices including clamps. Rather, power correction techniques can be implemented using devices such as scrapers and ligatures.

[0273] Electrosurgical devices (e.g., forceps 14) may include two or more electrodes, which are sized, shaped, and / or otherwise configured to deliver electrotherapy signals to biological tissue (e.g., Figure 1 (Organization 16). In some examples, the electrodes can be coupled with jaws (e.g., as shown in the image). Figure 1 The first jaw member 36 and the second jaw member 38 are integrated. In other examples, the electrodes may be coupled to the jaws.

[0274] Output circuit (e.g., including) Figure 2 The power supply 44) can be configured to generate electrosurgical energy and deliver the electrosurgical energy to the output terminal (e.g., Figure 2 The instrument interface 42) is used for delivery to the patient. The output terminal can be configured to couple to an electrosurgical device (e.g., Figure 1 The forceps 14), and deliver electrosurgical energy (e.g., high frequency such as RF energy) to the biological tissue via electrotherapy signals. The control circuitry of the surgical system (e.g., Figure 1 The control circuit 48) of the surgical system can be coupled to the output circuit, and the control circuit can be configured to perform various aspects of the power correction technique.

[0275] Figure 17 This is a flowchart depicting an example of a power correction technique that can be used in a surgical system. At box 1300, the measurement circuit (e.g., Figure 2 The measurement circuit 46) measures the positioning of the electrosurgical device (e.g., Figure 1 The impedance of the tissue between the two electrodes of the clamp 14) is represented. In some examples, the control circuit can measure the central tendency (e.g., mean, median, mode, or other central tendency) of the output during a portion of the period (e.g., the last 50ms of the output) and store these values, for example... Figure 2 In memory 56.

[0276] At block 1302, the control circuit can compare the measured impedance with the value stored in memory (e.g., ...). Figure 2The first threshold (e.g., about 50 ohms) in the memory 56 is compared. The first threshold (e.g., 50 ohms) can be based on an impedance value below which the electrosurgical system requires power correction. The first threshold can be adjusted based on the electrosurgical system.

[0277] If the impedance is not less than a first threshold (the "No" branch of box 1302), the impedance is high enough that the control circuit does not need to apply power correction to the power control of the electrosurgical generator, as shown in box 1304. The electrosurgical system can apply power via normal operation.

[0278] However, if the impedance is less than a first threshold (the "Yes" branch of block 1302), the control circuitry can apply a power correction to the power control of the electrosurgical generator. For example, as shown in block 1306, the control circuitry can determine whether the measured impedance is within a first impedance range (e.g., 0 ohms to 100 ohms). If the measured impedance is within the first impedance range (the "Yes" branch of block 1306), the control circuitry can select a first power correction associated with the first impedance range and apply the selected first power correction at block 1308.

[0279] If the measured impedance is not within the first impedance range (the "No" branch of box 1306), then when the impedance is represented within the second range (e.g., 20 ohms to 100 ohms), the control circuitry can select a second power correction associated with the second impedance range (e.g., 20 ohms to 100 ohms) and apply the selected second power correction at box 1310. As an example, the "desired power" could be 100W, but in reality, the system can only measure 50W. A correction factor can be applied to the measured value to ensure that the correct compensation is applied to the output.

[0280] Electrosurgical systems can use linear calculations to apply power corrections, such as the following formula:

[0281] Corrected power = (((Zload×A)+B)×Measured power) / 1000 Equation (1)

[0282] Where Zload is the impedance of the tissue being measured, A and B are specific power correction values ​​or parameters that can be selected to provide different possible power correction trajectories, and the measured power is the power (V×I) that the electrosurgical system believes it is delivering to the tissue. The processor (e.g., Figure 2 The processor 54) can access memory (e.g., Figure 2The memory 56) retrieves parameters A and B, and uses the above equation (1) to calculate the corrected power setting. In a first non-limiting example for illustrative purposes only, the first calculation for a power correction of 10 ohms may use value 11 for A and value 548 for B. In a second non-limiting example for illustrative purposes only, the first calculation for a power correction of 50 ohms may use value 11 for A and value 419 for B.

[0283] Using a calibrated power setting, the control circuitry can deliver electrosurgical energy via the electrodes of an electrosurgical device. In some examples, the control circuitry can reduce or terminate the application of a selected power correction to the power setting when the impedance representation meets or exceeds a threshold. Continuing with the examples described above, the control circuitry can initially apply a power correction for a measured impedance of 15 ohms (which is below 50 ohms and falls within a first range of 0 to 20 ohms), and reduce or terminate the application of that power correction when the measured impedance exceeds 20 ohms (which is above the upper limit of the first range). In some examples, the control circuitry can initiate the application of a new power correction based on a change in impedance. Continuing with the examples above, for a measured impedance of 21 ohms (which is below 50 ohms and falls within a second range of 20 to 50 ohms), the control circuitry can apply a new power correction to the power setting.

[0284] In some examples, instead of a single impedance value (e.g., 20 ohms) representing the difference between a first range (e.g., 0 ohms to 20 ohms) and a second range (e.g., 20 ohms to 50 ohms), the control circuitry can be expected to use hysteresis to prevent the system from oscillating between two power corrections. When implemented, the hysteresis can dynamically change the threshold limits based on the system's current "state," preventing unintentional oscillations between at least two thresholds when the measured parameter approaches the threshold. It can affect one or both of the upper and lower thresholds. In this way, the control circuitry can dynamically adjust at least one of the upper and lower limits of the first range when the impedance representation is within a predetermined percentage of the upper or lower limit or within the upper or lower limit value.

[0285] For example, a specified percentage can be used at the boundaries of the range. As an example, for the impedance measured within 20% of the upper limit of 20 ohms in the first range, the control circuitry can use one or both of the upper and lower limits associated with the first range that can be dynamically adjusted (e.g., increased).

[0286] In another example, instead of using percentages for hysteresis, the control circuitry can use specified impedance values ​​at the boundaries of the range. As an example, for a measured impedance within 4 ohms of the 20-ohm upper limit of the first range, the control circuitry can dynamically adjust (e.g., increase) one or both of the upper and lower limits associated with the first range.

[0287] It should be noted that although two non-limiting examples of ranges are described using two corresponding power corrections, in some examples, a single range may provide sufficient power correction. In other examples, more than two ranges with corresponding power corrections may be used.

[0288] The power correction techniques described above can significantly improve power control in electrosurgical systems, artificially overcoming accuracy deficiencies. However, in some examples, auxiliary parameters can be used to provide even higher accuracy. For example, power correction can be based on output during the "tissue sampling" phase. If the tissue has one characteristic, a first power correction can be used. If the tissue has another characteristic, a second power correction can be used. Examples of characteristics that can be used to determine power correction include, but are not limited to: energy delivered over a period of time, calculated impedance, current draw, voltage phase angle, tissue temperature, etc. The processor can use these characteristics individually or in combination to select power correction. For example, the processor can use tissue temperature and calculated impedance to select power correction.

[0289] In an example of using one or more auxiliary parameters to determine power correction, the measurement circuit can measure the impedance representation of tissue positioned between two electrodes of an electrosurgical device, compare the measured impedance representation to a first threshold, and if the impedance is less than the first threshold (e.g., 50 ohms), as described above... Figure 17 As described, a first power correction is selected from two or more power corrections. The control circuit can then compare the representation of one or more auxiliary parameters with one or more thresholds. When the representation of one(s) auxiliary parameters is less than one(s) threshold, the control circuit can select between the previously selected first power correction and one or more other power corrections. The control circuit can determine that the previously selected first power correction is sufficient, or it can determine, based on auxiliary parameters (e.g., the output current of the power generator), tissue temperature, and voltage phase angle, that different power corrections will be desired to be applied to the power setting.

[0290] In some examples, if the impedance is less than a first threshold (e.g., 50 ohms), the control circuitry can select auxiliary power correction. As the impedance increases, the control circuitry can then select primary power correction. As the increase continues, the adjusted power setting can utilize standard generator control without any power correction.

[0291] In some examples, power calibration can be used for specific time periods (e.g., using tissue feedback). For instance, using calibrated power settings, control circuitry can deliver electrosurgical energy via the electrodes of an electrosurgical device over a period of time, or until a certain amount of energy is applied, or a combination of both, within a range of impedance values. Additionally, external metrics such as time periods or user-defined parameters can be applied.

[0292] Figure 24 This is a flowchart depicting another example of a power correction technique that can be used in surgical systems. Figure 24 A dual-decision flowchart is described, which uses impedance to determine which power correction to apply. Additionally, the flowchart can use impedance as a decision point for when to apply and when to stop applying power correction.

[0293] At box 2400, phase 1A can be completed, and the generator output can stabilize. At box 2402, phase 1B can begin, and the control circuitry can determine the average impedance organized during the last 50ms of phase 1B. At box 2404, the control circuitry can determine whether the average impedance is between 0 ohms and 20 ohms. If the average impedance is between 0 ohms and 20 ohms (the "Yes" branch of box 2404), then at box 2406, the control circuitry can apply a first power correction value "X" to phase 2.

[0294] If the average impedance is not between 0 ohms and 20 ohms (the "No" branch of box 2404), then at box 2408, the control circuit can determine whether the average impedance is between 20.01 ohms and 50 ohms. If the average impedance is between 20.01 ohms and 50 ohms (the "Yes" branch of box 2408), then at box 2410, the control circuit can apply the second power correction value "Y" to stage 2. If the average impedance is not between 20.01 ohms and 50 ohms (the "No" branch of box 2408), then at box 2412, the control circuit can determine that stage 2 does not require power correction.

[0295] Reduced heat margin combined energy equipment ( Figure 18 and Figure 19 )

[0296] Surgical systems exist that can deliver two types of energy—ultrasound energy and electrosurgical energy, such as high-frequency energy. Ultrasound energy can provide rapid and precise tissue cutting, while electrosurgical energy can provide reliable vascular closure. The system can deliver both types of energy simultaneously, or the delivery can be controlled to deliver the two types of energy separately.

[0297] Figure 18This is a simplified block diagram of an example of a combined ultrasonic energy and electrosurgical energy system that can implement various techniques of the present disclosure. System 1400 may include a surgical device 1402 coupled to an ultrasonic drive unit 1404 and an electrosurgical drive unit 1406. Additional information regarding such a combined ultrasonic energy and electrosurgical energy system can be found in US 8,574,228, co-transmitted by Okada et al., entitled “ULTRASOUND TREATMENT SYSTEM,” the entire contents of which are incorporated herein by reference. Surgical device 1400 may include an ultrasonic transducer 1408 and a probe 1410. Ultrasonic drive unit 1404 may include a first output circuit 1412 configured to generate a drive signal applied to ultrasonic transducer 1408 to generate ultrasonic vibrations delivered to biological tissue via probe 1402.

[0298] System 1400 may include control circuitry configured to control various aspects of the operation of the ultrasound drive unit 1404 and the electrosurgical drive unit 1406. For example, control circuitry 1414 may be configured to generate and apply signals to a first output circuit 1412 of the ultrasound drive unit 1404, and to generate and apply signals to a second output circuit 1416 of the electrosurgical drive unit 1406. In some example configurations, control circuitry 1414 may include... Figure 2 The control circuit 48 is similar to the component, and is related to Figure 2 The control circuit 48 operates similarly. In some example configurations, the electrosurgical drive unit 1406 may include... Figure 2 Similar components to the electrosurgical generator 12, and with Figure 2 The electrosurgical generator 12 operates similarly. The second output circuit 1416 can generate a high-frequency electrotherapy signal to be delivered to biological tissue via probe 1410. The first output circuit 1412 and the second output circuit 1416 are coupled to control circuitry 1414 and configured to generate energy and deliver it to the system's output terminals for delivery to the patient. In some examples, the system may include a speaker 1418 and / or a display 1422 to provide the user with alarms or other auditory and / or visual notifications.

[0299] In some examples, the surgical device 1402 may be similar to U.S. Patent Application Publication No. US20120010539, co-assigned by Yachi et al. and entitled “OPERATION DEVICE AND SURGICAL APPARATUS”. Figure 1 Surgical devices, the entire contents of which are incorporated herein by reference. U.S. Patent Application Publication No. US20120010539 Figure 1 Surgical equipment can perform procedures such as cutting and removing living tissue by using ultrasound combined with the application of high-frequency waves. Additionally, ultrasound can be used to coagulate living tissue.

[0300] In some examples, the electrosurgical drive unit 1406 may include measurement circuitry 1420. Measurement circuitry 1420 may be similar to... Figure 2 The measurement circuit 46 can be configured to measure one or more electrical parameters of biological tissue coupled to the surgical device 1402.

[0301] Appropriate power delivery is a crucial factor in achieving optimal tissue efficacy during vascular occlusion. Too much energy, too fast, can create a vapor pocket within the tissue, potentially causing damage to the tissue surrounding the surgical instrument. This phenomenon is commonly referred to as "thermal margin." Combined ultrasound and electrosurgical energy systems often use waveforms with slack-rate outputs, such as constant pulse rates or high-frequency energy (e.g., RF energy), along with ultrasound energy, and layer them on top of each other. This can lead to undesirable consequences such as heating of the surgical instrument tip and increased thermal margin.

[0302] The inventors have recognized the need to monitor feedback from the tissue in combined ultrasound and electrosurgical energy systems to determine whether a desired vapor bag has been generated. Using various techniques described below, combined ultrasound and electrosurgical energy systems can monitor feedback from the tissue, such as changes in the drawn current, changes in impedance, or changes in impedance over time, to provide an indication that a desired vapor bag has been generated. Instead of continuing to apply energy to the tissue, one or both of the high-frequency energy (e.g., RF energy) and ultrasound energy can be reduced or stopped.

[0303] The use of combined ultrasound energy and electrosurgical energy systems (e.g., Figure 18 System 1400) is a non-limiting, specific example of modifying biological tissue using various techniques described herein. The combined ultrasound and electrosurgical energy system can deliver energy in at least two modes: a first mode comprising ultrasound energy and a second mode comprising bipolar energy. Control circuitry (e.g., Figure 18 The control circuit 1414 can control the measurement circuit (e.g., Figure 18 The measurement circuit 1420 measures a representation of tissue impedance to monitor feedback from tissue in contact with the surgical device. For example, the control circuit can monitor changes in the impedance value, which may indicate that a maximum preferred amount of vapor has been generated in the tissue, and that additional vapor generation may cause excessive heat margin. In other example implementations, the control circuit may monitor changes in the drawn current and / or impedance value (e.g., absolute impedance value).

[0304] Once the change in impedance value reaches or exceeds the threshold, the control circuit can control the ultrasonic drive unit (e.g., Figure 18 The ultrasound drive unit 1404 can be used to stop the ultrasound output. Additionally, the control circuit can control the electrosurgical drive unit (e.g., Figure 18 The electrosurgical drive unit 1406 reduces the output of the high-frequency electrotherapy signal generated by the second output circuit 1416 of the electrosurgical drive unit 1406. For example, the high-frequency output can be reduced to the point that the vapor generated in the tissue can be partially or completely restored to a liquid state. Once this liquid state is achieved, as determined by the control circuit using a set time, feedback control, or both, the system 1400 can apply power again until a time is met that vapor generation limits are satisfied, or the end of the energy application cycle is met, for example, by user decision or by feedback control.

[0305] Figure 19 This is a flowchart illustrating an example of a heat margin reduction technique that can be used in a system combining ultrasound energy and electrosurgical energy. At block 1500, control circuitry can control the delivery of energy to biological tissue positioned between two electrodes of an electrosurgical device, wherein the delivered energy includes at least some ultrasound energy. For example, Figure 18 The control circuit 1414 can control the first output circuit 1412 to output to... Figure 18 The surgical device 1402 delivers ultrasound energy to the tissue in contact with it and controls the second output circuit 1416 to direct ultrasound energy to the tissue in contact with it. Figure 18 The surgical device 1402 delivers high-frequency energy (e.g., RF energy) to the tissue in contact with it. For example, the surgical device may include an ultrasonic forceps with HF electrodes on its jaws.

[0306] At box 1502, the measurement circuitry can measure representations of tissue parameters (e.g., impedance) of biological tissue. For example, Figure 18 The measurement circuit 1420 measures the change in current drawn and / or impedance value (e.g., absolute impedance value or change in impedance (relative value)).

[0307] At box 1504, the control circuitry can reduce the level of energy delivery or terminate energy delivery based on measured representations of tissue parameters of the biological tissue. Example characteristics may include, but are not limited to, the following: resistance, impedance, current, phase angle, current consumed and / or required voltage, and changes (increments) of one or more of these characteristics, as well as combinations of these characteristics. For example, Figure 18 The control circuit 1420 can control Figure 18 The first output circuit 1412 reduces the level of ultrasonic energy. In some examples, the control circuit 1420 can control the first output circuit 1412 to terminate or reduce the delivery of ultrasonic energy. Termination is an example of reducing the delivery of ultrasonic energy.

[0308] In some examples, the delivered energy can be modified, for example, by increasing the energy or by temporarily decreasing the energy but allowing it to return to its previous level after a short time interval. Temporarily decreasing the energy can mean temporarily reducing it to or nearing no energy delivery, such as aborting it.

[0309] In some examples, in contrast to the energy pause at the active endpoint, the control circuitry can pause energy delivery to allow vapor condensation. By pausing energy delivery, the system can establish a fluid condensation residence time. The system does not require monitoring tissue parameters to identify the endpoint of the combined high-frequency / ultrasound therapy pulse.

[0310] In other examples, control circuitry 1420 may control first output circuitry 1412 to reduce the level of electrosurgical energy. In some examples, control circuitry 1420 may control first output circuitry 1412 to terminate the delivery of electrosurgical energy.

[0311] For example, as described above, the electrosurgical energy can be power-controlled or voltage-controlled. In a power-controlled implementation, the control circuit 1420 can control the second output circuit 1416 to deliver electrosurgical energy, for example, according to a plan, scheme, or arrangement, using the product of the voltage applied across the joined biological tissue and the current output by the second output circuit 1416. For example, the control circuit can control the second output circuit 1416 to deliver constant power or monotonically increasing power during a specific phase (e.g., the drying phase).

[0312] In a voltage control implementation, the control circuit can, for example, control the voltage of the electrosurgical energy delivered by the second output circuit 1416 according to a plan, scheme, or arrangement. For example, the control circuit can control the second output circuit 1416 to deliver a constant voltage or a monotonically increasing voltage during a specific phase (e.g., a drying phase).

[0313] As described above, the control circuit can reduce or terminate energy delivery based on the characteristics of a representation of the measured biological tissue impedance. In some examples, the characteristics of the representation of the measured impedance are impedance values, such as absolute or relative impedance values. In some such examples, the control circuit can be configured to compare the measured impedance value with a threshold and reduce or terminate energy delivery based on that comparison. For example, the control circuit can reduce the delivery level of one or both of ultrasound energy and electrosurgical energy, periodically reduce the delivery level of one or both of ultrasound energy and electrosurgical energy, or terminate the delivery of one or both of ultrasound energy and electrosurgical energy based on this comparison. By periodically reducing the level, the system can reduce power at various stages during a single output, where the output is during a fully activated process.

[0314] In other examples, the measured impedance is characterized by a change in impedance value. In some such examples, the control circuit can be configured to compare the change in impedance value with a threshold and, based on that comparison, reduce the level of energy delivery or terminate energy delivery. For example, the control circuit can, based on that comparison, reduce the level of delivery of one or both of ultrasound energy and electrosurgical energy or terminate the delivery of one or both of ultrasound energy and electrosurgical energy.

[0315] When the techniques described above are used in combination with ultrasound energy and electrosurgical energy systems, the total power output of the system can be reduced when a steam bag is generated, which can reduce undesirable thermal margin.

[0316] Graded impedance values ​​used to control thermal margin in systems with slow CPUs ( Figure 20 and Figure 21 )

[0317] High performance is typically expected without increasing the system's processing load. If processing power is kept low, slower systems that may be cheaper to buy or maintain can perform better.

[0318] Typically, steam control and thermal margin control for equipment used in vasoconstriction can be achieved by monitoring one or more feedback systems. The feedback system can be a single true feedback element or multiple interdependent feedback elements, for example, through a decision tree structure or calculations based on one or more events.

[0319] Examples of such systems can monitor the difference (or increment) between the lowest encountered calculated impedance and the impedance fluctuating. In other examples, the rate of impedance rise over time, changes in phase angle, changes in drawn current, and changes in voltage can be used as indicators of vapor generation within tissue.

[0320] When monitoring the difference (or increment) between the minimum encountered calculated impedance and the rolling upper limit impedance, newer fast-response hardware, for example, can use specific boundaries or decision points to determine whether the expected steam bag has been generated, and if so, whether the size of the bag necessitates a reduction, brief cessation, or complete power shutdown. In older, slower reaction systems, the rate of steam bag generation is the same, but the response time for reducing or stopping power is slower, which can cause a "steam bag overshoot" that may result in a larger thermal margin.

[0321] As an example, if the impedance threshold is set at 55 ohms, older, slower systems may exceed the 55-ohm threshold and stop at 70 ohms. In contrast, newer electrosurgical systems may include faster analog-to-digital converters, processors, and other hardware that allows sampling at millions of samples per second. In such systems, if the impedance threshold is set at 55 ohms, the newer system may stop at the desired level of approximately 55 ohms.

[0322] The inventors have recognized the need to improve thermal margin control in conventional electrosurgical systems. Through extensive observation of tissue effects, the inventors have realized that overshoot typically occurs in the early pulse phase of the electrosurgical waveform, and the rate of vapor generation decreases throughout the waveform as tissue dries through fluid drainage. Therefore, to address the overshoot problem and improve thermal margin control, the inventors have recognized the desire to incorporate intelligence into the output. In particular, the inventors have realized that electrosurgical systems can count the pulses of the electrosurgical signal and can assign different values ​​of triggers or thresholds, such as impedance values ​​or impedance increments, based on the number of pulses. In this way, the threshold of one or more initial electrosurgical energy pulses can be reduced, which can allow overshoot and thus reduce the thermal margin of conventional electrosurgical systems.

[0323] As mentioned above, Figure 2 Examples of surgical systems that can be used to implement various aspects of the thermal margin control techniques of this disclosure are described. For example... Figure 1 As shown, Figure 1 The surgical system may include an electrosurgical device such as forceps 14. Forceps 14 may include two jaws, such as a first jaw member 36 and a second jaw member 38. In some examples, one of the two jaws may be movable, while the other jaw may be fixed. In other examples, both jaws may be movable.

[0324] It should be noted that the thermal margin control techniques disclosed herein are not limited to electrosurgical devices including clamps. Rather, thermal margin control techniques can be implemented using devices such as scrapers and ligatures.

[0325] Electrosurgical devices (e.g., forceps 14) may include two or more electrodes, which are sized, shaped, and / or otherwise configured to deliver electrotherapy signals to biological tissue (e.g., Figure 1 (Organization 16). In some examples, the electrodes can be coupled with jaws (e.g., as shown in the image). Figure 1 The first jaw member 36 and the second jaw member 38 are integrated. In other examples, the electrodes may be coupled to the jaws.

[0326] Output circuit (e.g., including) Figure 2The power supply 44) can be configured to generate electrosurgical energy and deliver the electrosurgical energy to the output terminal (e.g., Figure 2 The instrument interface 42) is used for delivery to the patient. The output terminal can be configured to couple to an electrosurgical device (e.g., Figure 1 The forceps 14), and deliver electrosurgical energy (e.g., high frequency such as RF energy) to the biological tissue via electrotherapy signals. The control circuitry of the surgical system (e.g., Figure 1 The control circuit 48) of the surgical system can be coupled to the output circuit, and the control circuit can be configured to perform various aspects of thermal margin control technology.

[0327] Figure 20 This is a flowchart depicting an example of thermal margin control technology that can be used in an electrosurgical system. At box 1600, a user, such as a surgeon or clinician, can initiate the delivery of electrosurgical energy to the patient's biological tissue (e.g., tissue positioned between the two jaws of an electrosurgical device). At box 1602, control circuitry (e.g., Figure 2 The control circuit 48 of system 10 can count the number of delivered electrosurgical pulses.

[0328] At box 1604, the control circuitry can compare a parameter to a threshold. In some examples, the parameter may be the impedance of the biological tissue, a change (or increment) in the impedance of the biological tissue, the rate of change of the impedance of the biological tissue, a change in the current of the delivered electrosurgical energy pulse, a change in the output voltage of the delivered electrosurgical energy pulse, or a change in the phase angle (e.g., the phase angle between the voltage difference delivered across the biological tissue and the current conducted by the biological tissue). In some examples, the measurement circuitry (e.g., Figure 2 The measurement circuit 46) measures parameters or measurements that can be made by a control unit (e.g., Figure 2 The processor 54) is used to calculate the electrical characteristics of the parameters. In some examples, the control circuitry can reduce the delivery of multiple electrosurgical energy pulses when the measured impedance representation meets or exceeds the endpoint value (e.g., an endpoint value of about 100 ohms to 600 ohms).

[0329] At box 1606, the control circuitry can adjust the threshold based on the count of electrosurgical energy pulses. That is, the threshold can change with each pulse. For example, for the second pulse, the control circuitry can adjust the impedance increment from, for example, 40 ohms upwards to 45 ohms. In this way, the control circuitry can set the threshold or boundary based on the pulse count. Customizing the threshold for one or more initial electrosurgical pulses based on the pulse count can help address any overshoot caused by delays in older, slower-responding electrosurgical generator systems.

[0330] As a non-limiting example, it might be desirable to deliver an energy pulse that produces an impedance change (or impedance increment) of approximately 55 ohms in biological tissue. When the user initiates the delivery of the first pulse of electrosurgical energy, the control circuitry (e.g., Figure 2 The control circuit 48) can control the counter (e.g., in...) Figure 2 The processor 54 is reset and a threshold value for a parameter (e.g., a change in impedance) is set to a first value. For example, the control circuitry can access the memory device (e.g., Figure 2 The memory 56) retrieves data representing the threshold of the first pulse and sets the threshold of the impedance increment of the first pulse to the retrieved data (e.g., representing 40 ohms).

[0331] The system can deliver a first pulse of energy, and the control circuitry can compare a measured parameter (e.g., impedance increment) to a threshold of 40 ohms. Once the measured parameter reaches 40 ohms, the control circuitry can stop the delivery of the first pulse. Due to delays in older, slower-responding electrosurgical generator systems, the system may exceed the 40-ohm threshold, and the system may actually stop once the impedance increment reaches approximately 55 ohms. A lower threshold for the first pulse allows for a rapid rise of the first pulse, providing an actual impedance of 55 ohms in the event of overshoot due to the system's slow response. As mentioned above, in some examples, an impedance increment of 55 ohms may be desirable.

[0332] Next, when preparing to deliver the second pulse, the control circuit can adjust the threshold based on the count of the electrosurgical pulses. Here, the count is two, and the control circuit can retrieve data representing the threshold of the second pulse from the memory device and set the threshold of the impedance increment of the second pulse to the retrieved data (e.g., representing 45 ohms).

[0333] The system can deliver a second pulse of energy, and the control circuitry can compare the measured parameter with an adjusted 45-ohm threshold. Once the measured parameter reaches 45 ohms, the control circuitry can stop the delivery of the second pulse. Due to a delay, the system may exceed the 45-ohm threshold, and can practically stop once the impedance increment reaches approximately 55 ohms. The adjusted threshold for the second pulse allows for a slightly slower ramp rate, thus providing an actual impedance of 55 ohms due to the system's slow response.

[0334] Next, when preparing to deliver the third pulse, the control circuit can adjust the threshold based on the count of the electrosurgical pulses. Here, the count is three, and the control circuit can retrieve data representing the threshold of the third pulse from a memory device (or use previously retrieved data), and set the threshold of the impedance increment of the third pulse to the retrieved data (e.g., representing 55 ohms).

[0335] The system can deliver a third pulse of energy, and the control circuit can compare the measured parameters with a pre-adjusted 55-ohm threshold. Once the measured parameter reaches 55 ohms, the control circuit can stop delivering the third pulse. Using the third pulse, the ramp rate can be slow enough that the system can react and stop promptly once the impedance increment reaches 55 ohms.

[0336] In this way, the threshold of one or more pulses in the initial electrosurgical energy pulse can be artificially lowered because, despite adjustments of 40 ohms, 45 ohms, etc., the desired threshold of, for example, 55 ohms remains the same. This artificial lowering of the threshold can allow overshoot and thus reduce the thermal margin of conventional electrosurgical systems. It may not be necessary to adjust the thresholds of additional pulses such as the fourth, fifth, and higher pulses. For example, the fourth, fifth, and higher pulses can be set to, for example, 55 ohms. In other examples, the third, fourth, fifth, and higher pulses can be adjusted.

[0337] In addition to the hierarchical pulse capability described above, the control circuit can use a predictor to determine or select a set of pulse ratios to use. For example, the ratio can be between each of the adjusted thresholds and the desired threshold. As a non-limiting example for illustrative purposes only, if the desired threshold is 55 ohms and the first pulse threshold, second pulse threshold, and third pulse threshold are 40, 45, and 50, respectively, then the ratios can be 40 / 55, 45 / 50, and 50 / 55.

[0338] The predictor can identify the likelihood of an impedance rise and takes this rise into account in the calculation of the adjusted thresholds. For example, a tissue with a high initial impedance that drops to a low impedance in the first pulse can indicate a rapid rise and therefore a decrease in the percentage of the impedance increment being searched. This could be because a tissue with a high initial impedance that drops abruptly can indicate a tissue with a large amount of fluid and therefore a rapid vapor rise. However, tissues with a lower starting impedance that drops even lower can have different ratio selectors or a set of thresholds.

[0339] Various parameters that can be used as predictors may include: the impedance of biological tissue, the change (or increment) of the impedance of biological tissue, the rate of change of the impedance of biological tissue, the current change of the delivered electrosurgical energy pulse, the output voltage change of the delivered electrosurgical energy pulse, or the change of phase angle (e.g., the phase angle between the voltage difference delivered across biological tissue and the current conducted by biological tissue).

[0340] In some examples, the control circuit (e.g., Figure 2The control circuit 48) can compare the first measurement parameter with the second measurement parameter and adjust the threshold based on the difference between the first measurement parameter and the second measurement parameter. For example, the measurement circuit (e.g. Figure 2 The measurement circuit 46) can measure, for example, a first impedance increment before the delivery of the first pulse and a second impedance increment, for example, after the delivery of the first pulse. Based on the difference between the first impedance increment and the second impedance increment, the control circuit can select a specific set of adjusted impedances.

[0341] As a non-limiting example, the control circuit may have a first set of adjusted impedance increment thresholds for the initial selection of the first pulse, the second pulse, and the third pulse, for example, 40 ohms, 45 ohms, and 55 ohms, respectively. However, based on the difference between the first impedance increment and the second impedance increment, the control circuit may select a second set of adjusted impedance increment thresholds for the first pulse, the second pulse, and the third pulse, for example, 45 ohms, 50 ohms, and 55 ohms, respectively.

[0342] In some examples, the control circuit can adjust the threshold based on the first measured parameter being greater than the second measured parameter. In other examples, the control circuit can adjust the threshold based on the first measured parameter being less than the second measured parameter. In some examples, the control circuit can adjust the threshold based on the rate of change between the first and second measured parameters.

[0343] Other factors can also be used to predict the correct ratio to use. For example, the rate of decrease of the initial impedance relative to time can be used to indicate the rate of increase, and thus the correct threshold or trigger. Alternatively, the initial impedance or even previous tissue activation can be used as a predictor. Previous tissue activation could be, for example, the last time a surgeon grasped the tissue and pressed the activation button.

[0344] Figure 21 This is a flowchart illustrating another example of thermal margin control techniques that can be used in electrosurgical systems. (Control circuitry, for example,...) Figure 2 The control circuit 48 of system 10 can count the number of delivered electrosurgical pulses. In some examples, the control circuit can count the number of pulses delivered from a memory device (e.g., Figure 2 The memory 56) retrieves data representing the first (and more) thresholds. At box 1700, a user, such as a surgeon or clinician, can initiate the delivery of a first electrosurgical energy pulse to the patient's biological tissue (e.g., tissue positioned between the two jaws of the electrosurgical device).

[0345] At block 1702, the control circuitry can compare a first measured impedance representation of the biological tissue (e.g., impedance increment) with a first threshold (e.g., 40 ohms). In some examples, the measured impedance representation may be: the impedance of the biological tissue, a change (or increment) in the impedance of the biological tissue, the rate of change of the impedance of the biological tissue, or a change in the current of the delivered electrosurgical energy pulse. In some examples, the measurement circuitry (e.g., Figure 2 The measurement circuit 46) measures impedance, or the measurement can be performed by a control unit (e.g., Figure 2 The processor 54) is used to calculate the electrical characteristics of the impedance representation. In some examples, the control circuitry can reduce the delivery of multiple electrosurgical energy pulses when the measured impedance representation meets or exceeds the endpoint value (e.g., an endpoint value of about 250 ohms to 350 ohms).

[0346] At block 1704, when the first measured impedance indicates that the first threshold is met or exceeded, the control circuit can reduce or terminate the delivery of the first electrosurgical energy pulse. For example, when the measured impedance increment meets or exceeds the 40-ohm threshold associated with the first pulse, the control circuit can reduce or terminate the delivery of the first pulse.

[0347] At block 1706, the control circuit can increase a first threshold to a second threshold based on the pulse count. For example, based on a count of two, the control circuit can increase a 40-ohm impedance increment threshold associated with the first pulse to a 45-ohm impedance increment threshold associated with the second pulse.

[0348] At box 1708, the control circuit can control the electrosurgical generator (e.g., Figure 2 An electrosurgical generator 12) is used to deliver a second electrosurgical energy pulse to the tissue. At block 1710, control circuitry can compare a second measured impedance representation of the biological tissue (e.g., impedance increment) with a second threshold (e.g., 45 ohms).

[0349] At block 1712, when the second measured impedance indicates that the second threshold is met or exceeded, the control circuit can reduce or terminate the delivery of the second electrosurgical energy pulse. For example, when the measured impedance increment meets or exceeds the adjusted 45-ohm threshold of the second pulse, the control circuit can reduce or terminate the delivery of the second pulse.

[0350] In some examples, when preparing to deliver the third pulse, the control circuitry can adjust the threshold based on the count of the electrosurgical pulses. Here, the count is three, and the control circuitry can retrieve data representing the threshold of the third pulse from a memory device (or use previously retrieved data), and set the threshold of the impedance increment of the third pulse to the retrieved data (e.g., representing 55 ohms).

[0351] As referenced above Figure 20 As described above, a predictor can be used to determine or select a set of pulse ratios to use. For example, a control circuit (e.g.) Figure 2 The control circuit 48) can compare the first measurement parameter with the second measurement parameter and adjust the threshold based on the difference between the first measurement parameter and the second measurement parameter. For example, the measurement circuit (e.g. Figure 2 The measurement circuit 46) can measure, for example, a first impedance increment before the delivery of the first pulse and a second impedance increment, for example, after the delivery of the first pulse. Based on the difference between the first impedance increment and the second impedance increment, the control circuit can select a specific set of adjusted impedances.

[0352] By using the above example about Figure 20 and Figure 21 The described thermal margin control technique allows for the artificial reduction of the threshold of one or more pulses in the initial electrosurgical energy pulse. This artificial reduction of the threshold can allow overshoot and thus reduce the thermal margin of conventional electrosurgical systems.

[0353] Although described separately, the aforementioned dual-boundary thresholding technique, open-circuit inspection technique, power correction technique, heat margin reduction technique for combined ultrasound energy and electrosurgical energy systems, and heat margin control technique may be implemented individually or in combination of two or more techniques described in this disclosure, as needed.

[0354] For example, a system implementing dual-boundary threshold technology can also implement one or more of the power correction techniques described above, heat margin reduction techniques for systems combining ultrasound energy and electrosurgical energy, and heat margin control techniques. As a non-limiting example, and for illustrative purposes only, a system implementing dual-boundary threshold technology can also implement heat margin control techniques capable of artificially reducing the threshold.

[0355] In another non-limiting example, for illustrative purposes only, a combined ultrasound and electrosurgical energy system that implements a heat margin reduction technique by reducing the energy delivery level or terminating energy delivery based on the characteristics of the impedance representation of the measured biological tissue can also implement a power correction technique that can apply power correction to the power control of the electrosurgical generator based on whether the measured impedance is within, for example, an impedance range of 0 ohms to 20 ohms.

[0356] Energy consumption monitoring and open circuit assessment ( Figures 22A to 22D )

[0357] To help determine whether to continue with an additional tissue drying phase, the inventors have recognized that at the end of the drying phase, the amount of energy (and / or charge) delivered to the tissue during the just-completed drying phase (or the just-completed interrogation and drying phases) can be assessed, as described in detail below. If the amount of energy (and / or charge) applied is below an energy (and / or charge) threshold and a sufficient impedance increment has been generated, the tissue is sufficiently dry, and processing can proceed to the next phase. However, if the amount of energy (and / or charge) applied is above an energy (and / or charge) threshold and a sufficient impedance increment has been generated, the tissue is too wet and requires another drying phase.

[0358] Figures 22A to 22D A flowchart depicts an example of an energy delivery technology that can utilize the amount of energy delivered to biological tissues, among other things, during its decision-making process. Although... Figures 22A to 22D The technology depicted in the flowchart is described as power-controlled, but in some examples, the technology can be voltage-controlled.

[0359] exist Figures 22A to 22D The flowchart depicts three steps, which are described in detail below. The portion of the flowchart labeled Step 1 (which could be an interrogation phase or other low-energy phase) could be a power-controlled step (or, in other examples, a voltage-controlled step), in which an electrosurgical generator (e.g., Figure 2 The electrosurgical generator 12) can control the delivery of low-power electrotherapy signals (e.g., 10W) ​​to biological tissue. In some examples, step 1 can be considered a vapor dissipation stage, in which the vapor generated in the tissue during step 2 is allowed to dissipate to prevent thermal margin.

[0360] In some examples, step 1 can be set to run for a specific duration, such as 250 ms, during which the electrosurgical generator can control the power as tightly as possible to ensure a consistent delivery level. During step 1, the control circuitry (e.g., Figure 2 Control circuit 48) and measurement circuit (e.g. Figure 2 The measurement circuit 46) combination can track various parameters. For example, the control circuit and measurement circuit can initiate measurements and store the maximum and minimum impedances associated with a specific delivery pulse (pulse RMax and pulse RMin) (also tracked in step 2). Additionally, during the application of power in steps 1 and 2, the control circuit and measurement circuit can store the value of the amount of energy (and / or charge) delivered to the tissue.

[0361] The amount of energy delivered to tissue can be measured in joules and is the integral of the amount of power delivered, measured in watts. The amount of charge delivered to tissue can be measured in coulombs and is the integral of the amount of current, measured in amperes. Although the amount of energy delivered to tissue is generally shown and described below, Figures 22A to 22D The technology can additionally or alternatively utilize the amount of charge delivered to the tissue.

[0362] Figure 22A The method shown begins at box 1800, where the electrosurgical generator (e.g. Figure 2 The electrosurgical generator 12) is energized. At box 1802, the method proceeds to step 1, and the electrosurgical generator can deliver a constant power output "A" during duration "B". At box 1804, the measurement and control circuitry can read or calculate the impedance value of the tissue, and the control circuitry can then average these values. In some examples, the average impedance determined during step 1 can influence the selection of the ramp rate used to apply energy in step 2 (the next power control phase).

[0363] exist Figure 22B At box 1806, the method proceeds to step 2, which can be the drying stage. At box 1806, the control circuit can automatically select the power ramp rate based on the impedance value determined in step 1. Different segments or ranges of impedance values ​​can produce different output power ramp rates. For example, for a lower impedance range, such as 1 ohm to 15 ohms, the control circuit can select ramp "E" (box 1808) (e.g., 0.05 W / ms), while for a medium impedance range, such as 15 ohms to 75 ohms, the control circuit can select ramp "D" (box 1810) (e.g., 0.035 W / ms), and for a high impedance range, such as 75 ohms to 400 ohms, the control circuit can select power ramp "F" (box 1812) (e.g., 0.035 W / ms). In some examples, there may be only two ramps, such as a fast first ramp and a slower second ramp, as... Figure 4 The values ​​t1 to t2 and t2 to t3 are shown in block 1814. After selecting the power slope, the control circuit can set the accumulated pulse energy (and / or charge) value to 0, and apply power to the tissue via an electrotherapy signal at block 1816.

[0364] Next, the method can perform activities in parallel, including controlling the circuitry at box 1818 to read or calculate the tissue's impedance and at box 1820 to read or calculate the energy (and / or charge) applied during that particular phase. In some examples, instead of running in parallel, the activities can be mixed in a single process.

[0365] At box 1820, the control circuit can read and calculate the energy (e.g., in joules) (and / or charge, e.g., in coulombs) applied to the biological tissue during this phase. Then, at box 1822, the control circuit can add the energy (and / or charge) applied during this phase to the pulse energy (and / or charge) value to generate a cumulative applied energy (and / or charge) value.

[0366] exist Figure 22A In the example shown, and in parallel with the calculation of the applied energy, after calculating the impedance in box 1818, at box 1824... Figure 2 The control circuit 48 can determine whether the impedance is less than the previous impedance Rmin. In some examples, the control circuit can start with a default initial impedance (e.g., 1000 ohms) when determining the minimum impedance Rmin. For example, if the next measured or calculated impedance is 20 ohms, then 20 ohms is the new minimum impedance Rmin. Similarly, if the subsequent measured or calculated impedance is 15 ohms, then 15 ohms is the new minimum impedance Rmin. The minimum impedance Rmin can come from step 1 or from the current impedance reading.

[0367] If the current impedance reading is lower than the previous impedance Rmin (the "Yes" branch of box 1824), then at box 1826, the control circuit can store the current impedance reading as the new minimum resistance value Rmin. Then, at box 1828, the control circuit can increase the power, for example, along a specific power slope trajectory (power increases over time).

[0368] At block 1830, the control circuitry can determine whether the power is greater than the maximum power level (power "H") of step 2. If the power is not greater than the maximum power level (the "No" branch of block 1830), the process returns to block 1816 and begins another stage. However, if the power is greater than the maximum power level (the "Yes" branch of block 1830), at block 1832 the control circuitry can adjust or change the power slope to a second slope. In some examples, the second slope is slower than the first slope.

[0369] At block 1834, the control circuit can determine whether the applied power is greater than the maximum power level. If the power is not greater than the maximum power level (the "No" branch of block 1834), the process returns to block 1816 and begins another stage. However, if the power is greater than the maximum power level (the "Yes" branch of block 1834), at block 1836 the control circuit can change the power slope to the maximum power level setting, and then the process returns to block 1816 and begins another stage.

[0370] Returning to decision box 1824, if the current impedance reading is not lower than the minimum impedance Rmin (the "No" branch of box 1824), then at box 1838 the control circuit can determine whether the current impedance reading is greater than the minimum impedance Rmin plus the impedance increment. If the current impedance reading is not greater than the minimum impedance Rmin plus the impedance increment (the "No" branch of box 1838), then the control circuit can move to box 1828, and the method can continue as described above.

[0371] In some examples, instead of determining at step 1824 whether the measured current is less than a predetermined fraction of the maximum current, control circuit 48 may determine whether the measured current is less than a predetermined fraction (or offset) of the current value measured at a predetermined time interval after pulse initiation. For impedance monitoring systems, control circuit 48 may determine whether the measured impedance is greater than a predetermined fraction (or offset) of the impedance value measured at a predetermined time interval after pulse initiation.

[0372] However, if the current impedance reading is greater than the minimum impedance Rmin plus the impedance increment (the "Yes" branch of box 1838), the control circuit can move to decision box 1840. As a non-limiting example, the impedance increment could be 55 ohms, the current impedance reading could be 75 ohms, and the minimum impedance Rmin could be 15 ohms. In this non-limiting example, if the current impedance reading (e.g., 75 ohms) is greater than the minimum impedance Rmin (e.g., 15 ohms) plus the impedance increment (e.g., 55 ohms) (the "Yes" branch of box 1838), the control circuit can move to decision box 1840.

[0373] As described above, the control circuit determines whether there is a set difference between the current impedance reading and the minimum impedance Rmin. If this difference is greater than a set amount, such as 55 ohms, the control circuit can now check how much energy was delivered during the previous step 1 and the current step 2 phase at this point in time. At box 1840, the control circuit can determine whether the amount of applied energy (or charge) is less than an energy threshold (or charge threshold), such as 20 joules (or 2 coulombs of charge). If the amount of applied energy is not less than the energy threshold (the "No" branch of box 1840), the control circuit can reset the minimum impedance Rmin at box 1842 and return to step 1. Finally, the system will return to the second drying cycle in step 2. In this way, if the amount of delivered energy exceeds the energy threshold, the control circuit can control the energy delivery of the therapeutic signal provided to the bonded biological tissue during the second drying phase.

[0374] However, if the amount of energy (or charge) applied is less than the energy threshold (or charge threshold) (the "Yes" branch of box 1840), the control circuitry, as shown in box 1844, can terminate the pulse and proceed to step 3. In this way, if the amount of energy delivered is less than the threshold energy value, the control circuitry can control the delivery of energy for the therapeutic signal supplied to the joined biological tissue during the completion phase.

[0375] It could be step 3 in the final stage. Figure 22C The target final impedance begins at box 1846. At box 1846, the control circuitry can store or record the target final impedance. In some examples, the target final impedance can be a set final value. In some examples, the target final impedance can be calculated incrementally based on the lowest impedance value read or calculated in this step, plus a predetermined percentage or increment. For example, if the minimum impedance Rmin in this step is measured to be 20 ohms, a predetermined increment of 280 ohms can be added to the final target impedance to set the target final impedance value to 300 ohms. In some examples, the target final impedance can be calculated incrementally based on an impedance measurement taken after a predetermined time interval following pulse initiation, plus a predetermined percentage or increment.

[0376] In some examples, the target final impedance may depend on the number of pulses (e.g., drying pulses). For example, if the endpoint depends on the number of pulses and two pulses are delivered to the tissue, the final impedance value might be 320 ohms. However, if five pulses are delivered to the tissue, the final impedance might be 280 ohms. If the endpoint is not reached within a predetermined time period (e.g., 2 seconds), the method may return to step 1 to attempt further drainage of fluid from the tissue and to reach a satisfactory endpoint impedance.

[0377] At box 1848, the control circuitry can, for example, reset and start a timer in response to the delivery of electrosurgical energy to biological tissue (e.g., biological tissue positioned between the two jaws of an electrosurgical device or in contact with one or more electrodes). If the predetermined impedance increment between the current impedance reading and the minimum impedance Rmin for that pulse is not met before the time interval is reached, the output returns to the first step, as this may indicate that the tissue still contains excessive water.

[0378] At box 1850, the control circuitry can set the power output to power level "I". In some examples, the control circuitry can use a constant power slope to control the delivery of the electrotherapy signal to the tissue. In some examples, the constant power slope in step 3 can be slower than a previous slope, such as in step 2. The control circuitry can continue delivery using a constant power slope until a final impedance value is reached, for example, 320 ohms in a non-limiting example.

[0379] At box 1852, the control circuitry can begin monitoring the tissue impedance. As described below, for example at boxes 1862 and 1872, the control circuitry can intermittently compare the impedance representation of the biological tissue with a threshold and continue delivering electrosurgical energy until the threshold is met. At box 1854, the control circuitry can increase the power to a constant power slope "J". In some examples, the control circuitry can deliver electrosurgical energy at a constant power slope before delivering it at a constant power slope.

[0380] At box 1856, the control circuit can determine whether the power is greater than the maximum power level in step 3. If the power is greater than the maximum power level in step 3 (the "Yes" branch of box 1856), then... Figure 22D The control circuit at box 1858 can set the power to the maximum power level of step 3. After setting the power to the maximum power level of step 3 at box 1858, or if the power is not greater than the maximum power level of step 3 (the "No" branch of box 1856), the control circuit at decision box 1860 can compare the timer value with the time interval "R".

[0381] If the timer value is not greater than or equal to the time interval "R" (the "No" branch of box 1860), the method can return to box 1854, and the control circuit can increase the power. However, if the timer value is greater than or equal to the time interval "R" (the "Yes" branch of box 1860), the control circuit at box 1862 can determine whether the impedance is greater than the minimum value within the pulse plus a predetermined incremental impedance, where the predetermined incremental impedance is the difference between the measured impedance and the minimum value of the impedance measured within the pulse.

[0382] If the control circuit determines that the impedance is not greater than the target impedance minus the predetermined incremental impedance (the "No" branch of box 1862), the method shown in box 1864 can return to step 1. In this way, the control circuit can change the predetermined incremental impedance value in response to the measured (e.g., intermittently measured) impedance, thereby reducing or terminating energy delivery during the treatment phase.

[0383] However, if the control circuit determines that the impedance is greater than the target impedance minus the predetermined incremental impedance (the "Yes" branch of box 1862), the method can move to box 1866 and increase the power to the power slope "J".

[0384] At decision box 1868, the control circuit can determine whether the current power is greater than the maximum step 3 power level. If the current power is greater than the maximum step 3 power level (the "Yes" branch of box 1868), then at box 1870 the control circuit can reset the power to the maximum step 3 power level "Q".

[0385] After setting the power to the maximum power level of step 3 at box 1870, or if the power is not greater than the maximum power level of step 3 (the "No" branch of box 1868), the control circuit can determine at box 1872 whether the impedance is greater than the target final impedance "P". If the control circuit determines that the impedance is greater than the target final impedance (the "Yes" branch of box 1872), the closure is completed at box 1874, and the control circuit can shut down the electrosurgical generator. However, if the control circuit determines that the impedance is not greater than the target final impedance (the "No" branch of box 1872), the control circuit can determine at box 1876 whether the timer is greater than the maximum step 3 output timer.

[0386] If the timer exceeds the maximum step 3 output timer (the "Yes" branch of box 1876), the method can return to step 1 as shown in box 1878. For example, if the timer times out, this can indicate that the tissue was not sufficiently dried during the previous step. However, if the timer does not exceed the maximum step 3 output timer (the "No" branch of box 1876), the method can return to box 1866 to increase the power slope.

[0387] In some examples, the timer at box 1860 can be used to detect potential open circuit conditions. For example, if an open circuit, such as..., is opened during the closing process... Figure 1 If the jaws of the forceps 14 of the electrosurgical device are not properly positioned, the electrosurgical generator may incorrectly determine that the accompanying increase in impedance is a result of tissue drying.

[0388] Figures 22A to 2 The unrestricted values ​​of parameters A to S in section 2 are shown in Table 1 below:

[0389] Table 1:

[0390] A 10W B 250ms D 0.035W / ms E 0.05W / ms F 0.035W / ms H 60W I 15W J 0.035W / ms P 320 ohms Q 100W R 100ms S 20 ohms

[0391] According to the disclosure, during step 3, a timer at block 1860 can be started. When the target final impedance (or threshold) is reached, the control circuit can record the elapsed time. If the target final impedance (or threshold) is reached within a very short time period, such as before the threshold time limit, the control circuit can determine that an open circuit has occurred rather than a complete closure and declare an error state. In other words, if the elapsed time is less than the time limit, the control circuit can declare an error state. The time limit can be 50ms, 100ms, or another time period.

[0392] For example, the control circuitry can determine the difference between the minimum measured impedance Rmin and the current or maximum measured impedance, and compare the determined difference with a predetermined incremental impedance value. In some examples, the control circuitry can increase the power slope of the electrosurgical energy in response to this comparison. The control circuitry can continue to increase the power slope (e.g., at block 1854) until the determined difference meets or exceeds the predetermined incremental impedance value (e.g., at block 1862), or reaches a power limit (e.g., at block 1858).

[0393] However, in some examples, if the determined difference is equal to or greater than a predetermined incremental impedance value and the timer exceeds a threshold timeout, the control circuit can declare an error state and generate an error signal. In some examples, an open-circuit error signal can be generated by the control circuit, for example, using... Figure 2 The user interface 50 sends an error message to the user and quickly terminates power supply to the electrosurgical device.

[0394] In some examples, the control circuitry does not terminate power supply at the time marker. Instead, power supply may continue until the final impedance is reached. At this point, the control circuitry can evaluate the time interval to see if mitigation is needed. For example, setting the time interval or threshold too long may produce false negatives (e.g., a good seal is formed, but the system has already determined an open circuit), especially on thin tissue that is being rapidly sealed. Setting the time interval or threshold too short may produce false positives (e.g., a good seal is not formed, but the system does not detect the error), which could occur, for example, when the user slowly opens the jaws.

[0395] Dwell time between pulses

[0396] It may be desirable to use pulsed waveforms to deliver electrotherapy signals. By pulsed electrosurgical signals, the tissue between the jaws of the device can be heated. Without pulsed signals, the tissue can become hot, and this heating typically increases with increasing applied energy as the tissue passes through different temperature ranges, allowing the fluid within the tissue to reach its boiling point. The boiling point can depend on the composition of the fluid being boiled, and also on the pressure at which the jaws clamp the tissue (changing the pressure changes the boiling point). This leads to the generation of vapor.

[0397] The generated steam increases tissue impedance, thus requiring less heating current to flow through the tissue and more voltage to be driven into it. The steam grows into a steam bag, and because the steam undergoes a phase change as it evaporates, the bag now has a larger volume. This new, larger volume further increases impedance, thus requiring more voltage to achieve the same power input. Simultaneously, the steam now shifts from its previous position between the jaws and extends into the surrounding tissue.

[0398] The higher voltage required to power these steam bags increases tissue adhesion to the energy application surface (e.g., the jaws), while steam leakage from the application site into the surrounding tissue is negative (known as thermal margin). Thermal margin can damage structures not intended for tissue modification and can ultimately lead to postoperative tissue necrosis and perforation of vital organs or organ structures. To overcome the propagation of steam bags into surrounding tissues and the high required driving voltage, pulsed control is currently used.

[0399] Pulsation refers to a pause in the application of energy delivered to tissue at a level capable of altering the tissue. In some examples, energy delivery is stopped for a period of time. In other examples, the energy level may be reduced to a level where the energy has no significant tissue effect. It may be desirable to apply at least some energy to the tissue rather than stopping delivery completely to allow for continuous or near-instantaneous feedback of tissue state to the control circuitry.

[0400] In some methods, a fixed period of 250 ms can be used as a pause period or "dwell time," which ensures that the vapor bag has condensed significantly before energy is reapplied. The dwell time is the time interval between the first pulse and the second pulse. If a dwell time of less than 250 ms is used, the vapor bag may not be fully depleted, and subsequent energy application can quickly restore it.

[0401] While a pause of less than 250 ms is generally correct for the first pulse, it is less clear for subsequent pulses. For the second pulse, a dwell time such as 200 ms may be appropriate, depending on the volume of tissue present between the jaws and its associated water content. Subsequent pulses may require even less time (e.g., the fifth pulse may require 50 ms or less) to allow for recondensation of the now greatly reduced fluid content between the device jaws.

[0402] During these "residence times," the fluid may migrate back into the target tissue. During these residence times, the generator can deliver a low-power signal to the tissue, low enough not to trigger tissue effects. A slight decrease in tissue thickness is often a result of vascular closure, where the compressed tissue contains fluid. Fluids can also be expelled by vapors with high pressure that push more mobile elements out of the area between the device's application plates, such as extracellular fluids.

[0403] Unfortunately, not all tissues have the same fluid levels or tissue fluid mobility, and not even the same amount of tissue thickness or width is clamped between the jaws of each closure device. Thus, a fixed standard reduction in the pause period between pulses may not provide an effective or accurate pause time controller.

[0404] Furthermore, there may be pressure to minimize the time required for full activation. Estimating a long dwell time and applying it even to a conservative approach that doesn't require such a long dwell period could unnecessarily prolong full activation. Unnecessarily prolonged full activation could extend the procedure time and potentially increase user fatigue, among other things.

[0405] To overcome the aforementioned problems, the inventors have recognized that control circuitry can accurately predict the most suitable reduced pause period using known characteristics of the tissue between the jaws. For example, the control circuitry can query a stored dataset (e.g., a lookup table) and determine the reduced pause period, or "dwell time," using one or more known characteristics of the tissue. The reduced dwell time can reduce the full activation time of the closure cycle without affecting the low thermal margin while still providing a high degree of confidence in reliable closure.

[0406] In some examples, control circuitry (e.g.) Figure 2 The control circuit 48) can deliver a first electrosurgical energy pulse and a second electrosurgical energy pulse to biological tissue that is electrically connected to the two electrodes of a surgical device (e.g., physically coupled to the two electrodes of the surgical device, positioned between the two electrodes of the surgical device, or otherwise coupled to the two electrodes of the surgical device), wherein the first electrosurgical energy pulse and the second electrosurgical energy pulse are separated from each other by corresponding residence times. The control circuit can then determine a residence time corresponding to at least one of the electrosurgical energy pulses following the first electrosurgical energy pulse.

[0407] In some examples, control circuitry (e.g.) Figure 2 The control circuit 48) can determine and use the amount of energy applied to the tissue to determine the optimal residence time. The amount of fluid between the jaws of the device requires a specific amount of energy to boil at a known energy application rate. The control circuit can estimate the amount of fluid present by determining how much energy is delivered to the jaws to produce a thermodynamic change in the tissue. The control circuit can use the determined amount of energy delivered to query a stored dataset to identify the appropriate corresponding residence time. For large steam generation pulse cycles using a large amount of energy, the control circuit can provide a longer residence time for condensation, and for smaller steam generation pulse cycles using a smaller amount of energy, the control circuit can provide a shorter residence time for condensation.

[0408] In other examples, instead of using a stored dataset (e.g., a lookup table), the control circuit can determine the dwell time as a ratio of the energy applied to the jaws. In other examples, the control circuit can determine the dwell time as a multiple of the energy applied to the jaws. As a non-limiting example, if the energy applied to the jaws is 20 joules, the dwell time can be 200 ms (X*10 ms). Therefore, 30 joules can correspond to 300 ms. Equation X*10 is illustrative and not limiting. It can also be part of a logarithmic scale or other mathematically based ratio term.

[0409] Additionally, determining the time required for the tissue to boil between the jaws (using a set or known variable power) is another way to determine a residence time long enough to ensure sufficient cooling mechanisms have occurred before applying energy to the tissue for the next level of tissue modification. In some examples, the control circuitry may attempt to cut off the power if the tissue has not boiled or has only minimal boiling. If a longer time is required for the tissue to boil as more energy is delivered, the control circuitry may determine that a longer residence time is needed. For example, the control circuitry may start a timer when a pulse is delivered, determine if the tissue has boiled or is close to boiling, and if so, stop the timer, compare the timer with one or more values ​​associated with the corresponding residence time, and determine or select the residence time based on that comparison. The residence time can be increased as the timer value increases. As a non-limiting example for illustrative purposes only, a residence time of 250 ms may be used if it takes 30 joules to boil or nearly boil the tissue, while a residence time of 150 ms may be used if it takes 18 joules. These values ​​may depend on the surface area of ​​the jaws of the device used or other factors.

[0410] While the energy applied to the tissue can be a strong indicator of the amount of steam produced, the tissue's impedance can also affect the accuracy of the setting. For example, if the tissue has high electrical resistance (e.g., fat), more voltage and less current are required to boil the tissue, while if the tissue has good conductivity, current works and produces a large vapor pocket with the same amount of energy. Therefore, a system is desirable that uses energy application to determine residence time, thereby also determining and using the tissue impedance for the energy used to produce the boiling effect.

[0411] Control circuits can use other electrical characteristics to determine dwell time in order to check or improve the signal. These other electrical characteristics include one or more of the following: current, reactance, inductance, impedance, resistance, power, phase angle, and energy.

[0412] Steam is a result of the delivered current, which excites molecules within the tissue and causes heating. When more current is needed to heat the tissue, it suggests that more fluid should remain within the tissue, given that the resistivity of the tissue structure itself is much higher than its fluid content. Therefore, depending on the function of the electrotherapy signal, such as how the signal applies energy, it is desirable for the control circuitry to determine the peak current applied in the previous pulse, or the current delivered as a function of time, or the total amount of current delivered in the previous pulse. The control circuitry uses the determined current and queries a stored dataset (e.g., a lookup table) and determines or selects the residence time based on the comparison.

[0413] For example, control circuits (e.g.) Figure 2 The control circuit 48) can control and apply power to the tissue, where the current and voltage are allowed to fluctuate according to the tissue impedance (this is a simplified explanation for general understanding). The control circuit can determine, for example, the total amount of current applied in the previous pulse by integrating the amount of current delivered, which helps to understand how much vapor can be generated during energy application. Current (I) is equal to the rate of change of charge (Q) with respect to time (I = dQ / dt). Therefore, the integral of current I over a period of time is equal to the total amount of charge (Q) during that period of time.

[0414] Instead of using the total amount of energy delivered to the tissue, the inventors have determined that the total amount of charge delivered can be used to determine the residence time. In some examples, the control circuitry can determine the residence time as a ratio to or a multiple of the total amount of charge. In other examples, the control circuitry can determine the residence time using the total amount of charge by using a stored dataset (e.g., a lookup table) or by using some other mathematical derivation calculation to provide an appropriate residence time that is not necessarily the same for all energy pulses.

[0415] The dwell time can be further improved by including or excluding other factors as described above. An example of such exclusion is that if current is delivered over a period longer than 300 ms, the control circuitry can reduce the dwell time because the amount of tissue within the jaws can have a significant impact. In this case, the control circuitry can start a timer, compare the timer to a threshold (e.g., 300 ms), and determine the dwell time based on that comparison. Alternatively, one or more feedback signals (e.g., phase angles) can be used to predict the composition of the tissue between the energy-conducting elements. The control circuitry can then take these feedback signals into account as indications to determine the appropriate dwell time.

[0416] Incremental adjustment of control parameters as a function of the monitored variable

[0417] The initial transformation of collagen occurs at approximately 58 (±10) degrees Celsius (C), at which point the collagen fibers undergo conformal changes. The major transformation likely occurs at approximately 65 (±10) degrees Celsius, corresponding to the gelation process of collagen in an aqueous environment and caused by the breaking of internal crosslinks. Other important and significant temperature-constrained tissue modifications occur. At typical tissue temperatures between approximately 90 and 100 degrees Celsius, further phase transitions begin within the tissue, most notably the conversion of water into vapor. This change is undesirable because vapor is resistive, and although it displaces energy-competing fluids from the tissue, it can also damage surrounding tissues by migrating into adjacent structures. This is undesirable because such damage can be uncontrolled and may affect tissues outside the clamped area.

[0418] From a clinical perspective, this means that surgeons should be aware of any potential “thermal diffusion” when using the device and activating it close to sensitive adjacent structures. This is undesirable and can lead to unexpected tissue damage, such as perforation and necrosis. Both can occur immediately, or worse, many days after the energy is applied.

[0419] Tissues containing vapor also have higher electrical resistance than the same tissue containing liquid water. This means that more energy is converted from electric current to voltage to drive changes in tissue state. Since electric current typically heats via molecular excitation, limiting the time of the vapor phase is advantageous for good vascular closure.

[0420] The inventors have recognized the need for improved power control (or voltage control) techniques that attempt to maintain power output for a longer period in a favorable state of collagen transformation before loss of control and the occurrence of bubble field generation. Using various techniques described in detail below, electrosurgical generators (e.g.) Figure 2 The electrosurgical generator 12 can control the energy delivery of therapeutic signals to the biological tissue during a portion of the treatment phase, based on the incremental change in energy delivery as a function of the changes in the electrical parameters of the measured biological tissue.

[0421] Applying energy to tissue can generate steam. As the amount of steam increases, the impedance increases. This increase in impedance can be an indicator of steam generation. When impedance increases, for the same amount of power delivered, the current decreases while the voltage increases (P = V * I). If the control circuit continues to apply the same amount of power after it has determined that steam is being generated, steam generation will undesirably increase and may adversely affect adjacent tissues. However, by using the various techniques of this disclosure, the control circuit can monitor changes in electrical parameters (e.g., current or impedance) and reduce the power, for example, to keep the tissue in a state where steam generation has just begun but has not yet reached a large scale, which would be desirable in order to avoid undesirably creating a thermal margin that could affect collagen.

[0422] Control circuits and measurement circuits (e.g.) Figure 2 The control circuit 48 and the measurement circuit 46 can monitor the current output of the generator and can convert an increase or decrease in current into a corresponding increase or decrease in output power. In some examples, the correlation between an increase or decrease in current and subsequent control regarding increasing or decreasing power can be proportional.

[0423] In some examples, the control circuitry can adjust the power application to provide different power based on changes in the measured electrical parameters (e.g., current or impedance). The adjustment can be a function of changes in the measured electrical parameters of the biological tissue. In some examples, the function can be a curve. In other examples, the function can be a linear equation, such as a linear transformation of changes in the value of the measured electrical parameter (e.g., current or impedance) into changes in power or voltage (e.g., in watts or volts per second). The power (or voltage) can increase or decrease with changes in current. In some examples, the linear equation can be monotonic. In some examples, one or both of minimum and maximum values ​​can be defined, allowing the control circuitry to limit changes in power or voltage.

[0424] Figure 23 This is an example graph depicting the relationship between changes in the value of a measured electrical parameter and changes in power. Although specifically depicted as changes in current per unit time relative to changes in power per unit time in watts, the described technique is not limited to current or power. Figure 23 In the example shown, the y-axis of Figure 2100 can represent watts per second, and the x-axis can represent current change per second.

[0425] In the example, the linear equation defining line 2102 may include an offset such that the line does not pass through the origin, so that the power change is positive when the current change or the incremental current value is zero. For example, in graph 2100 of power change versus current change, line 2102 may have a positive slope and may extend through quadrants I, II, and III. As another example, in graph of voltage change versus current change, the line may have a negative slope and may extend through quadrants I, II, and IV. Figure 23 In the example shown, one or both of the maximum slope 2104 and the minimum slope 2106 can be defined so that the control circuit can limit, for example, the rate of power change.

[0426] In the example, the relationship between the measured changes in electrical parameters and the incremental changes in energy can be stored in a dataset (e.g., a lookup table). The control circuitry can query the stored dataset, compare the measured changes in the electrical parameters of the biological tissue with the stored dataset, and determine the incremental changes in energy delivery based on that comparison.

[0427] Whether using a function such as a linear function or a stored dataset, the control circuit can monitor electrical parameters such as changes in current, allowing it to adjust control parameters such as power or voltage in real time (or "instantaneously") to control the energy delivery of the therapeutic signal to the biological tissue during a portion of the treatment phase. In this way, the control circuit can control the electrical power or voltage of the therapeutic signal delivered to the biological tissue based on measured changes in the biological tissue's electrical parameters. For example, the control circuit can modify the electrical power or voltage incrementally based on the current.

[0428] As a non-limiting example, a small positive current rate change can produce a medium power rate change. As another example, a zero current rate change can produce a negative power rate change. As yet another example, a negative current rate change can produce a high negative power rate change. As yet another example, a high current rate change can produce a high power rate change. By monitoring the current increment (also known as current change), different power controls can be applied, which can drive different organizational results or be modified to suit different applying devices.

[0429] When power is applied, the current can increase because the tissue has not yet boiled, and the tissue becomes more conductive when heated. Therefore, more current is needed to increase the power. Various techniques using this disclosure are employed to control circuits (e.g., Figure 2 The control circuit 48) can allow power to increase because the current is still increasing, which can hopefully accelerate the time taken for collagen denaturation. Eventually, a state is reached where power cannot be applied to the tissue more quickly without causing tissue rupture. To avoid tissue rupture, the control circuit can limit the maximum power (or voltage) applied to the tissue.

[0430] As the amount of steam increases, the impedance increases. When impedance increases, for the same amount of power delivered, the current decreases while the voltage increases (P = V * I). If the control circuit determines that steam is being generated, it can quickly reduce the power, but not quickly enough to stop steam generation altogether. As the impedance continues to increase, the control circuit can determine the amount of energy delivered based on the impedance change. Using the determined amount of delivered energy, the control circuit can stop applying power and temporarily pause to allow the steam to collapse.

[0431] Biological tissues contain salts, and sodium burns when energy is applied to the tissue. Burning sodium can become highly conductive, which can affect the accuracy of measurements used to determine whether to increase or decrease power or voltage. To avoid making real-time decisions based on tiny, rapid changes such as those in burning sodium, electrosurgical generators (e.g., Figure 2The electrosurgical generator 12) may include or implement various filters. As an example, when considering changes in current increments, a filter can be added to the current sampling to smooth the generator output. The frequency of the filter can depend on the processing speed of the generator control CPU.

[0432] In some examples, the control circuitry can also determine whether a suggested increase or decrease in power (or voltage) should occur. For instance, the control circuitry can sample recent increases or decreases in power (or voltage) and determine whether a continued increase (or decrease) should continue, or whether the latest change in power ramp (or voltage ramp) is noise or within expected limits. For example, if the past two (or more) power ramp values ​​(or voltage ramp values) were positive and large, but the latest value indicates a significant negative (decreased) power, the control circuitry can ignore the decision to reduce power (or voltage) until subsequent current increment calculations are evaluated.

[0433] In some examples, the control circuitry may include boundaries for the maximum permissible variation and / or the maximum permissible output or ramp rate, thereby preventing the generator from being limited solely by its hardware or from applying energy to the tissue too quickly. This can be achieved by limiting the maximum power during the phase, limiting the maximum power variation (e.g., limiting the maximum watts per second ramp rate), etc.

[0434] These power (or voltage) control techniques, which can be used in single-slope waveform outputs or pulsed waveform outputs, control the energy delivery of the therapeutic signal to the biological tissue during a portion of the treatment phase based on the incremental changes in energy delivery as a function of changes in the electrical parameters of the measured biological tissue. The advantage of pulsed waveform outputs is that the power can be rapidly increased if needed. For example, under certain conditions, the power can be significantly reduced (or temporarily stopped) to allow vapor condensation and to allow power to be subsequently applied again in a ramping manner until the desired tissue effect "endpoint" is reached.

[0435] all aspects

[0436] To further illustrate the above electrosurgical techniques, a non-limiting list of aspects is described below. Each of the non-limiting aspects can exist independently, or can be combined with one or more other aspects in various permutations or combinations.

[0437] A. Short-circuit error capture with a band between the trigger value and the escape value.

[0438] Aspect A1 may include or use the following subject matter (e.g., systems, apparatus, methods, articles, etc.), which may include or use a surgical system comprising: control circuitry; and output circuitry coupled to the control circuitry and configured to deliver electrosurgical energy to an output terminal for delivery to a patient, the output terminal being configured to be coupled to an electrosurgical device having two electrodes, wherein the control circuitry is configured to: compare a first measured impedance value of biological tissue electrically connected to the two electrodes of the electrosurgical device with a first threshold; start a timer when the first measured impedance value is less than or equal to the first threshold; compare a second measured impedance value of tissue between the two electrodes with a second threshold, wherein the second threshold is greater than the first threshold; and continue delivering electrosurgical energy when the second measured impedance value is less than the second threshold and the timer has not yet met its time limit.

[0439] Aspect A2 may include or use at least some features of aspect A1, or may optionally combine with at least some features of aspect A1 to include or use: the control circuit is configured to reduce the delivery of electrosurgical energy when the second measured impedance value is less than the second threshold and the timer has met the time limit.

[0440] Aspect A3 may include or use at least some features of any one or more of aspects A1 or A2, or may optionally combine with at least some features of any one or more of aspects A1 or A2 to include or use: the control circuit is configured to generate an indication when the timer has met the time limit.

[0441] Aspect A4 may include or use at least some features of any one or more of aspects A1 to A3, or may optionally combine with at least some features of any one or more of aspects A1 to A3 to include or use: a timer of less than 6 seconds.

[0442] Aspect A5 may include or use at least some features of any one or more of aspects A1 to A4, or may optionally combine with at least some features of any one or more of aspects A1 to A4 to include or use: the control circuit is configured to adjust at least one of a first threshold, a second threshold, and a time limit based on at least one characteristic of the electrosurgical device or based on at least one characteristic of the electrosurgical generator configured to be coupled to the electrosurgical device.

[0443] Aspect A6 may include or use at least some features of any one or more of aspects A1 to A5, or may optionally be combined with at least some features of any one or more of aspects A1 to A5 to include or use: at least one feature includes the surface area of ​​at least one electrode.

[0444] Aspect A7 may include or use at least some features of any one or more of aspects A1 to A6, or may optionally combine with at least some features of any one or more of aspects A1 to A6 to include or use: an electrode positioned on the jaws of an electrosurgical device, and at least one of the features includes: jaw force of the electrosurgical device.

[0445] Aspect A8 may include or use at least some features of any one or more of aspects A1 to A7, or may optionally combine with at least some features of any one or more of aspects A1 to A7 to include or use: at least one feature includes the output current of the electrosurgical generator.

[0446] Aspect A9 may include or use at least some features of any one or more of aspects A1 to A8, or may optionally combine with at least some features of any one or more of aspects A1 to A8 to include or use: an electrode positioned on the jaws of an electrosurgical device, and biological tissue positioned between the two electrodes of the electrosurgical device.

[0447] Aspect A10 may include or use a method for delivering electrical energy to an electrosurgical device, the method comprising: initiating continuous delivery of electrosurgical energy to biological tissue electrically connected to two electrodes of the electrosurgical device; comparing a first measured impedance value of the tissue with a first threshold; initiating a timer when the first measured impedance value is less than or equal to the first threshold; comparing a second measured impedance value of the tissue with a second threshold, wherein the second threshold is greater than the first threshold; and continuing delivery of electrosurgical energy when the second measured impedance value is less than the second threshold and the timer has not yet met its time limit.

[0448] Aspect A11 may include or use at least some features of aspect A10, or may optionally combine with at least some features of aspect A10 to include or use: reducing the delivery of electrosurgical energy when the second measured impedance value is less than the second threshold and the timer has met the time limit.

[0449] Aspect A12 may include or use at least some features of any one or more of aspect A10 or aspect A11, or may optionally combine with at least some features of any one or more of aspect A10 or aspect A11 to include or use: generating an indication when a timer has met a time limit.

[0450] Aspect A13 may include or use at least some features of any one or more of aspects A10 to A12, or may optionally combine with at least some features of any one or more of aspects A10 to A12 to include or use: electrodes positioned on the jaws of the electrosurgical device, and biological tissue positioned between the two electrodes of the electrosurgical device.

[0451] Aspect A14 may include or use at least some features of any one or more of aspects A10 to A13, or may optionally combine with at least some features of any one or more of aspects A10 to A13 to include or use: a timer of less than 6 seconds.

[0452] Aspect A15 may include or use at least some features of any one or more of aspects A10 to A14, or may optionally combine with at least some features of any one or more of aspects A10 to A14 to include or use: adjusting at least one of the first threshold, the second threshold, and the time limit based on at least one characteristic of the electrosurgical device or based on at least one characteristic of the electrosurgical generator configured to be coupled to the electrosurgical device.

[0453] Aspect A16 may include or use at least some features of any one or more of aspects A10 to A15, or may optionally combine with at least some features of any one or more of aspects A10 to A15 to include or use: at least one characteristic of the electrosurgical device includes the surface area of ​​at least one electrode.

[0454] Aspect A17 may include or use at least some features of any one or more of aspects A10 to A16, or may optionally combine with at least some features of any one or more of aspects A10 to A16 to include or use: an electrode positioned on the jaws of an electrosurgical device, and at least one characteristic of the electrosurgical device including the jaw force of the electrosurgical device.

[0455] Aspect A18 may include or use at least some features of any one or more of aspects A10 to A17, or may optionally combine with at least some features of any one or more of aspects A10 to A17 to include or use: at least one characteristic of the electrosurgical generator includes the output current of the electrosurgical generator.

[0456] B. Open-circuit check of the RF waveform at the resistor-limited endpoint and evaluation of the open-circuit time in the final stage.

[0457] Aspect B1 may include or use the subject matter (e.g., system, apparatus, method, article, etc.) which may include or use a surgical system comprising: control circuitry; and output circuitry coupled to the control circuitry and configured to deliver electrosurgical energy to an output terminal for delivery to a patient, the output terminal being configured to be coupled to an electrosurgical device having two jaws with corresponding electrodes, wherein the control circuitry is configured to: initiate a timer in response to delivery of electrosurgical energy to biological tissue electrically connected to the two electrodes of the electrosurgical device; compare an impedance representation with a first threshold after the timer has satisfied a time limit; and continue delivery of electrosurgical energy when the impedance representation is less than the first threshold.

[0458] Aspect B2 may include or use at least some features of aspect B1, or may optionally combine with at least some features of aspect B1 to include or use: the control circuit is configured to reduce the delivery of electrosurgical energy when the impedance representation is greater than or equal to a first threshold and less than a second threshold.

[0459] Aspect B3 may include or use at least some features of aspect B1 or B2, or may optionally combine with at least some features of aspect B1 or B2 to include or use: the control circuit is configured to reduce the delivery of electrosurgical energy when the impedance representation is greater than or equal to a second threshold.

[0460] Aspect B4 may include or use at least some features of any one or more of aspects B1 to B3, or may optionally combine with at least some features of any one or more of aspects B1 to B3 to include or use: the control circuit is configured to generate an indication when the impedance representation is greater than or equal to the second threshold.

[0461] Aspect B5 may include or use at least some features of any one or more of aspects B1 to B4, or may optionally combine with at least some features of any one or more of aspects B1 to B4 to include or use: a control circuit configured to generate an indication when the impedance representation is greater than or equal to a second threshold, the control circuit being configured to generate an auditory indication.

[0462] Aspect B6 may include or use at least some features of any one or more of aspects B1 to B5, or may optionally combine with at least some features of any one or more of aspects B1 to B5 to include or use: control circuitry configured to generate an indication when the impedance representation is greater than or equal to a second threshold, the control circuitry being configured to generate a visual indication.

[0463] Aspect B7 may include or use at least some features of any one or more of aspects B1 to B6, or may optionally combine with at least some features of any one or more of aspects B1 to B6 to include or use: impedance representation includes the value of impedance.

[0464] Aspect B8 may include or use at least some features of any one or more of aspects B1 to B7, or may optionally combine with at least some features of any one or more of aspects B1 to B7 to include or use: impedance representation includes a change in impedance value.

[0465] Aspect B9 may include or use the subject matter (e.g., system, apparatus, method, article, etc.) which may include or use a surgical system comprising: control circuitry; and output circuitry coupled to the control circuitry and configured to deliver electrosurgical energy to an output terminal for delivery to a patient, the output terminal being configured to be coupled to an electrosurgical device having two jaws with corresponding electrodes, wherein the control circuitry is configured to: initiate a timer in response to the delivery of electrosurgical energy to biological tissue electrically connected to the two electrodes of the electrosurgical device; compare the rate of change of impedance of the biological tissue with a first threshold after the timer has elapsed; and continue the delivery of electrosurgical energy when the rate of change of impedance is less than the first threshold.

[0466] Aspect B10 may include or use at least some features of aspect B9, or may optionally combine with at least some features of aspect B9 to include or use: the control circuit is configured to reduce energy delivery when the rate of change of impedance is greater than or equal to a first threshold.

[0467] Aspect B11 may include or use at least some features of any one or more of aspects B9 or B10, or may optionally combine with at least some features of any one or more of aspects B9 or B10 to include or use: the control circuit is configured to generate an indication when the rate of change of impedance is greater than or equal to a first threshold.

[0468] Aspect B12 may include or use at least some features of any one or more of aspects B9 to B11, or may optionally combine with at least some features of any one or more of aspects B9 to B11 to include or use: a control circuit configured to generate an indication when the rate of change of impedance is greater than or equal to a first threshold, the control circuit being configured to generate an indication.

[0469] Aspect B13 may include or use the subject matter (e.g., system, apparatus, method, article, etc.) which may include or use a method for delivering electrical energy to an electrosurgical device, the method comprising: starting a timer in response to the delivery of electrosurgical energy to biological tissue electrically connected to two electrodes of the electrosurgical device; comparing an impedance representation of the biological tissue with a threshold; continuously delivering electrosurgical energy until the threshold is met; recording the elapsed time when the threshold is reached; and declaring an error state if the elapsed time is less than a time limit.

[0470] Aspect B14 may include or use at least some features of aspect B13, or may optionally combine with at least some features of aspect B13, to include or use: determining the difference between a first measured impedance and a second measured impedance and comparing the determined difference with a predetermined incremental impedance value; and generating an error signal in response to the determined difference being equal to or greater than the predetermined incremental impedance value and a timer being less than a threshold time limit.

[0471] Aspect B15 may include or use at least some features of any one or more of aspects B13 or B14, or may optionally combine with at least some features of any one or more of aspects B13 or B14 to include or use: determining the difference between a first measured impedance and a second measured impedance and comparing the determined difference with a predetermined incremental impedance value; and increasing the power slope of the electrosurgical energy in response to the comparison.

[0472] Aspect B16 may include or use at least some features of any one or more of aspects B13 to B15, or may optionally combine with at least some features of any one or more of aspects B13 to B15 to include or use: continuously increasing the power slope until the determined difference meets or exceeds a predetermined incremental impedance value or reaches a power limit.

[0473] Aspect B17 may include or use at least some features of any one or more of aspects B13 to B16, or may optionally combine with at least some features of any one or more of aspects B13 to B16 to include or use: a power slope is a first power slope, and in response to reaching a power limit, the power slope is adjusted from the first power slope to a second power slope, wherein the second power slope is slower than the first slope.

[0474] Aspect B18 may include or use at least some features of any one or more of aspects B13 to B17, or may optionally combine with at least some features of any one or more of aspects B13 to B17 to include or use: a threshold of a first threshold, and during the completion phase: comparing the impedance representation of the biological tissue with a second threshold; and delivering electrosurgical energy at a constant power slope until the impedance representation meets or exceeds the second threshold.

[0475] Aspect B19 may include or use at least some features of any one or more of aspects B13 to B18, or may optionally combine with at least some features of any one or more of aspects B13 to B18 to include or use: delivering electrosurgical energy at a constant power prior to delivering electrosurgical energy at a constant power slope.

[0476] C. Alternating power correction output in low-precision hardware systems

[0477] Aspect C1 may include or use the subject matter (e.g., system, apparatus, method, article, etc.) which may include or use a surgical system comprising: control circuitry; and output circuitry coupled to the control circuitry and configured to deliver electrosurgical energy to an output terminal for delivery to a patient, the output terminal being configured to be coupled to an electrosurgical device having two jaws with corresponding electrodes, wherein the control circuitry is configured to: compare an indication of impedance of biological tissue electrically connected to the two electrodes of the electrosurgical device with a first threshold; select a first power correction from at least two power corrections when the indication of impedance is within a first range; and apply the selected first power correction to a power setting of a power generator coupled to the electrosurgical device.

[0478] Aspect C2 may include or use at least some features of aspect C1, or may optionally combine with at least some features of aspect C1 to include or use: the control circuit is configured to select a second power correction from at least two power corrections when the impedance is represented in a second range.

[0479] Aspect C3 may include or use at least some features of any one or more of aspects C1 or C2, or may optionally combine with at least some features of any one or more of aspects C1 or C2 to include or use: the control circuit is configured to compare the representation of at least one auxiliary parameter with at least one threshold; and when the representation of at least one auxiliary parameter is less than at least one threshold, a third power correction is selected from at least two power corrections.

[0480] Aspect C4 may include or use at least some features of any one or more of aspects C1 to C3, or may optionally combine with at least some features of any one or more of aspects C1 to C3 to include or use: at least one auxiliary parameter including one or more of the power generator's output current, tissue temperature, and phase angle.

[0481] Aspect C5 may include or use at least some features of any one or more of aspects C1 to C4, or may optionally combine with at least some features of any one or more of aspects C1 to C4 to include or use: the control circuit is configured to deliver electrosurgical energy via the electrodes of the electrosurgical device over a period of time using a calibrated power setting.

[0482] Aspect C6 may include or use at least some features of any one or more of aspects C1 to C5, or may optionally combine with at least some features of any one or more of aspects C1 to C5 to include or use: a period of time based at least on the range of impedance values.

[0483] Aspect C7 may include or use at least some features of any one or more of aspects C1 to C6, or may optionally combine with at least some features of any one or more of aspects C1 to C6 to include or use: a period of time based at least on the amount of electrosurgical energy delivered.

[0484] Aspect C8 may include or use at least some features of any one or more of aspects C1 to C7, or may optionally combine with at least some features of any one or more of aspects C1 to C7 to include or use: the control circuit is configured to: deliver electrosurgical energy via the electrodes of the electrosurgical device using a calibrated power setting; and reduce the application of the selected first power calibration to the power setting when the impedance representation meets or exceeds a second threshold.

[0485] Aspect C9 may include or use at least some features of any one or more of aspects C1 to C8, or may optionally combine with at least some features of any one or more of aspects C1 to C8 to include or use: delivering electrosurgical energy via electrodes of an electrosurgical device using a calibrated power setting; and dynamically adjusting at least one of the upper and lower limits of a first range when the impedance is represented within a predetermined percentage or value of an upper or lower limit.

[0486] Aspect C10 may include or use the subject matter (e.g., system, apparatus, method, article, etc.) which may include or use a method for delivering electrical energy to an electrosurgical device, the method comprising: comparing an impedance representation of a biological tissue electrically connected to two electrodes of the electrosurgical device with a first threshold; selecting a first power correction from at least two power corrections when the impedance representation is within a first range; and applying the selected first power correction to a power setting of a power generator coupled to the electrosurgical device.

[0487] Aspect C11 may include or use at least some features of aspect C10, or may optionally combine with at least some features of aspect C10 to include or use: selecting a second power correction from at least two power corrections when the impedance is represented in a second range.

[0488] Aspect C12 may include or use at least some features of any one or more of aspects C10 or C11, or may optionally combine with at least some features of any one or more of aspects C10 or C11 to include or use: comparing the representation of at least one auxiliary parameter with at least one threshold; and selecting a third power correction from at least two power corrections when the representation of at least one auxiliary parameter is less than at least one threshold.

[0489] Aspect C13 may include or use at least some features of any one or more of aspects C10 to C12, or may optionally combine with at least some features of any one or more of aspects C10 to C12 to include or use: at least one auxiliary parameter including the output current of the power generator; tissue temperature; and phase angle.

[0490] Aspect C14 may include or use at least some features of any one or more of aspects C10 to C13, or may optionally combine with at least some features of any one or more of aspects C10 to C13 to include or use: delivering electrosurgical energy via electrodes of an electrosurgical device over a period of time using calibrated power settings.

[0491] Aspect C15 may include or use at least some features of any one or more of aspects C10 to C14, or may optionally combine with at least some features of any one or more of aspects C10 to C14 to include or use: a period of time based at least on a range of impedance values.

[0492] Aspect C16 may include or use at least some features of any one or more of aspects C10 to C15, or may optionally combine with at least some features of any one or more of aspects C10 to C15 to include or use: a period of time based at least on the amount of electrosurgical energy delivered.

[0493] Aspect C17 may include or use at least some features of any one or more of aspects C10 to C16, or may optionally combine with at least some features of any one or more of aspects C10 to C16 to include or use: delivering electrosurgical energy via electrodes of an electrosurgical device using a calibrated power setting; and reducing the application of a selected first power calibration to the power setting when the impedance representation meets or exceeds a second threshold.

[0494] Aspect C18 may include or use at least some features of any one or more of aspects C10 to C17, or may optionally combine with at least some features of any one or more of aspects C10 to C17 to include or use: delivering electrosurgical energy via electrodes of an electrosurgical device using a calibrated power setting; and applying a second power correction to the power setting when the impedance is expressed as a specified percentage above the upper limit of a first range.

[0495] D. Combined energy equipment to reduce heat margin

[0496] Aspect D1 may include or use the subject matter (e.g., system, apparatus, method, article, etc.) which may include or use a combined ultrasound energy and electrosurgical energy system, the system comprising: control circuitry; and output circuitry coupled to the control circuitry and configured to deliver energy to an output terminal for delivery to a patient, the output terminal being configured to be coupled to an electrosurgical device having two jaws with corresponding electrodes, wherein the delivered energy includes at least some ultrasound energy, wherein the control circuitry is configured to: control the delivery of energy to biological tissue electrically connected to the two electrodes of the electrosurgical device; measure the representation of tissue parameters of the biological tissue; and reduce the level of energy delivery or terminate energy delivery based on the characteristics of the representation of the measured tissue parameters of the biological tissue, wherein the delivered energy is a combination of electrosurgical energy and ultrasound energy, and wherein the control circuitry configured to reduce the level of energy delivery or terminate energy delivery is configured to: reduce the level of ultrasound energy.

[0497] Aspect D2 may include or use at least some features of aspect D1, or may optionally combine with at least some features of aspect D1 to include or use: a control circuit configured to reduce the level of ultrasonic energy is configured to terminate the delivery of ultrasonic energy.

[0498] Aspect D3 may include or use at least some features of any one or more of aspect D1 or aspect D2, or may optionally combine with at least some features of any one or more of aspect D1 or aspect D2 to include or use: the control circuit is configured to: reduce the level of electrosurgical energy.

[0499] Aspect D4 may include or use at least some features of any one or more of aspects D1 to D3, or may optionally combine with at least some features of any one or more of aspects D1 to D3 to include or use: a control circuit configured to reduce the level of electrosurgical energy is further configured to terminate the delivery of electrosurgical energy.

[0500] Aspect D5 may include or use at least some features of any one or more of aspects D1 to D4, or may optionally combine with at least some features of any one or more of aspects D1 to D4 to include or use: the delivered energy is a combination of electrosurgical energy and ultrasound energy, and the electrosurgical energy is power-controlled.

[0501] Aspect D6 may include or use at least some features of any one or more of aspects D1 to D5, or may optionally combine with at least some features of any one or more of aspects D1 to D5 to include or use: the delivered energy is a combination of electrosurgical energy and ultrasonic energy, and the electrosurgical energy is voltage-controlled.

[0502] Aspect D7 may include or use at least some features of any one or more of aspects D1 to D6, or may optionally combine with at least some features of any one or more of aspects D1 to D6 to include or use: the measured tissue parameter is represented as an impedance value, and the control circuit is configured to: compare the impedance value with a threshold; and reduce the level of ultrasound energy based on the comparison.

[0503] Aspect D8 may include or use at least some features of any one or more of aspects D1 to D7, or may optionally combine with at least some features of any one or more of aspects D1 to D7 to include or use: the measured tissue parameter is represented as an impedance change, the method comprising: comparing the impedance change with a threshold; and reducing the level of ultrasound energy based on the comparison.

[0504] Aspect D9 may include or use the subject matter (e.g., system, apparatus, method, article, etc.) which may include or use a method for delivering energy to a device combining ultrasound energy and electrosurgical energy, the method comprising: delivering energy to biological tissue electrically connected to two electrodes of the electrosurgical device, wherein the delivered energy includes at least some ultrasound energy; measuring a representation of tissue parameters of the biological tissue; and reducing the level of energy delivery or terminating energy delivery based on characteristics of the representation of the measured tissue parameters, wherein the delivered energy is a combination of electrosurgical energy and ultrasound energy, and wherein reducing the level of energy delivery or terminating energy delivery comprises: reducing the level of ultrasound energy.

[0505] Aspect D10 may include or use at least some features of aspect D9, or may optionally be combined with at least some features of aspect D9 to include or use: reducing the level of ultrasonic energy includes terminating the delivery of ultrasonic energy.

[0506] Aspect D11 may include or use at least some features of any one or more of aspects D9 or D10, or may optionally be combined with at least some features of any one or more of aspects D9 or D10 to include or use a reduced level of electrosurgical energy.

[0507] Aspect D12 may include or use at least some features of any one or more of aspects D9 to D11, or may optionally combine with at least some features of any one or more of aspects D9 to D11 to include or use: reducing the level of electrosurgical energy includes terminating the delivery of electrosurgical energy.

[0508] Aspect D13 may include or use at least some features of any one or more of aspects D9 to D12, or may optionally combine with at least some features of any one or more of aspects D9 to D12 to include or use: the delivered energy is a combination of electrosurgical energy and ultrasound energy, and the electrosurgical energy is power-controlled.

[0509] Aspect D14 may include or use at least some features of any one or more of aspects D9 to D13, or may optionally combine with at least some features of any one or more of aspects D9 to D13 to include or use: the delivered energy is a combination of electrosurgical energy and ultrasonic energy, and the electrosurgical energy is voltage-controlled.

[0510] Aspect D15 may include or use at least some features of any one or more of aspects D9 to D14, or may optionally combine with at least some features of any one or more of aspects D9 to D14 to include or use: the measured tissue parameter is represented as an impedance value, the method comprising: comparing the impedance value with a threshold; and reducing the level of ultrasound energy based on the comparison.

[0511] Aspect D16 may include or use at least some features of any one or more of aspects D9 to D15, or may optionally combine with at least some features of any one or more of aspects D9 to D15 to include or use: the measured tissue parameter is represented as an impedance change, the method comprising: comparing the impedance change with a threshold; and reducing the level of ultrasound energy based on the comparison.

[0512] E. Graded resistor values ​​used to control thermal margin in systems with slow CPUs

[0513] Aspect E1 may include or use the subject matter (e.g., system, apparatus, method, article, etc.) which may include or use a surgical system comprising: control circuitry; and output circuitry coupled to the control circuitry and configured to deliver energy to an output terminal for delivery to a patient, the output terminal being configured to be coupled to an electrosurgical device having at least one electrode, wherein the control circuitry is configured to: count electrosurgical energy pulses and deliver electrosurgical energy pulses to biological tissue in communication with at least one electrode; and for a plurality of electrosurgical energy pulses: compare parameters to a threshold; and adjust the threshold based on the count of the electrosurgical energy pulses.

[0514] Aspect E2 may include or use at least some features of aspect E1, or may optionally combine with at least some features of aspect E1 to include or use: parameters selected from the group consisting of: the impedance of biological tissue, the change in the impedance of biological tissue, the rate of change of the impedance of biological tissue, the change in phase angle, the change in the current of the delivered electrosurgical energy pulse, and the change in the output voltage of the delivered electrosurgical energy pulse.

[0515] Aspect E3 may include or use at least some features of any one or more of aspect E1 or aspect E2, or may optionally combine with at least some features of any one or more of aspect E1 or aspect E2 to include or use: the control circuitry is configured to: retrieve data representing a threshold from a memory device.

[0516] Aspect E4 may include or use at least some features of any one or more of aspects E1 to E3, or may optionally combine with at least some features of any one or more of aspects E1 to E3 to include or use: control circuitry configured to compare a first measurement parameter with a second measurement parameter, and wherein control circuitry configured to adjust a threshold based on the count of electrosurgical energy pulses is configured to adjust the threshold based on the difference between the first measurement parameter and the second measurement parameter.

[0517] Aspect E5 may include or use at least some features of any one or more of aspects E1 to E4, or may optionally combine with at least some...

Claims

1. A surgical generator configured to generate controlled electrical power for a therapeutic signal and to provide the controlled electrical power to biological tissue in electrical communication with an instrument, the surgical generator comprising: A control circuit connected to an electrical energy source, the electrical energy source being electrically coupled to the device and configured to generate the therapeutic signal, the control circuit being configured to: During a portion of the non-closed treatment phase, the electrical power supplied to the biological tissue is controlled according to the treatment plan by monotonically increasing the electrical power as a function of resistance. as well as Between the non-closed treatment phase and the subsequent treatment phase, the electrical power is reduced to a constant power with a non-zero level.

2. The surgical generator according to claim 1, wherein, The control circuit is configured to: The voltage of the therapeutic signal supplied to the biological tissue is controlled according to the treatment plan during a portion of the drying phase.

3. The surgical generator according to claim 2, wherein, The control circuit is configured to: Monitor the voltage of the treatment signal; and The voltage is maintained when the voltage meets the voltage threshold.

4. The surgical generator according to claim 1, wherein, The control circuit is configured to: A predefined power curve is used to control the electrical power of the therapeutic signal supplied to the biological tissue during a portion of the therapeutic phase.

5. The surgical generator according to claim 4, wherein, The predefined power curve includes a linear portion.

6. The surgical generator according to claim 4, wherein, The predefined power curve includes two or more linear components.

7. A computer-readable storage medium having a computer-executable program stored thereon, which, when executed by a processor, causes the processor to perform a method of delivering controlled electrical power of a therapeutic signal to biological tissue in electrical communication with an instrument, the method comprising: The therapeutic signal is generated using electrical energy coupled to the device; as well as During a portion of the non-closed treatment phase, the electrical power supplied to the biological tissue is controlled according to the treatment plan by monotonically increasing the electrical power as a function of resistance. as well as Between the non-closed treatment phase and the subsequent treatment phase, the electrical power is reduced to a constant power with a non-zero level.

8. The computer-readable storage medium of claim 7, wherein the method comprises: The voltage of the therapeutic signal supplied to the biological tissue is controlled according to the treatment plan during a portion of the drying phase.

9. The computer-readable storage medium of claim 8, wherein the method comprises: Monitor the voltage of the treatment signal; as well as The voltage is maintained when the voltage meets the voltage threshold.

10. The computer-readable storage medium of claim 7, wherein the method comprises: A predefined power curve is used to control the electrical power of the therapeutic signal supplied to the biological tissue during a portion of the therapeutic phase.

11. The computer-readable storage medium according to claim 10, wherein, The predefined power curve includes a linear portion.

12. The computer-readable storage medium according to claim 11, wherein, The predefined power curve includes two or more linear components.

13. A surgical generator configured to generate controlled electrical power for a therapeutic signal and to provide the controlled electrical power to biological tissue in electrical communication with an instrument, the surgical generator comprising: A control circuit connected to an electrical energy source, the electrical energy source being electrically coupled to the device and configured to generate the therapeutic signal, the control circuit being configured to: During a portion of the non-closed treatment phase, the electrical power supplied to the biological tissue is controlled according to the treatment plan by monotonically increasing the electrical power as a function of current. as well as Between the non-closed treatment phase and the subsequent treatment phase, the electrical power is reduced to a constant power with a non-zero level.

14. The surgical generator according to claim 13, wherein, The function of the current is a function of the instantaneously measured change in current.

15. A computer-readable storage medium having a computer-executable program stored thereon, which, when executed by a processor, causes the processor to perform a method of delivering controlled electrical power of a therapeutic signal to biological tissue in electrical communication with an instrument, the method comprising: The therapeutic signal is generated using electrical energy coupled to the device; as well as During a portion of the non-closed treatment phase, the electrical power supplied to the biological tissue is controlled according to the treatment plan by monotonically increasing the electrical power as a function of current. as well as Between the non-closed treatment phase and the subsequent treatment phase, the electrical power is reduced to a constant power with a non-zero level.

16. The computer-readable storage medium according to claim 15, wherein, The function of the current is a function of the instantaneously measured change in current.

17. The computer-readable storage medium of claim 16, wherein, The function of the instantaneously measured current change is a linear function.

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