Electrosurgical Sealing and Cutting System

Abstract

To provide a bipolar electrosurgical fusion / sealer and dissector 20 that is arranged to simultaneously fuse and cut a tissue captured between jaws of the instrument.SOLUTION: Jaws include particularly positioned, shaped, and oriented electrodes along with a compressible landing pad to perform simultaneous fusion and cutting of a tissue. An electrosurgical generator 10 is arranged to supply RF energy through an instrument. This electrosurgical generator monitors a phase angle of the supplied RF energy and adjusts or terminates the supplied RF energy on the basis of the monitored phase angle to optimally fuse and dissect the tissue.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates generally to electrosurgical systems and methods, and more particularly to electrosurgical fusing / sealing and cutting systems.

[0002] Description of Related Applications This application claims the benefit of U.S. Provisional Patent Application No. 62 / 005,009, filed May 30, 2014, and U.S. Provisional Patent Application No. 62 / 004,980, filed May 30, 2014, the disclosures of which are incorporated by reference in their entireties. [Background technology]

[0003] Electrosurgical instruments have become available that use electrical energy to perform certain surgical tasks. Typically, an electrosurgical instrument is a surgical instrument, such as a grasper, scissors, forceps, blade, or needle, that includes one or more electrodes configured to receive electrical energy from an electrosurgical unit that includes a power source. The electrical energy can be used to coagulate, melt, or cut tissue to which the electrical energy is applied.

[0004] Electrosurgical instruments typically fall into two categories: monopolar and bipolar. In monopolar instruments, electrical energy is supplied at a high current density to one or more electrodes of the instrument, and a separate return electrode is electrically coupled to the patient, often designed to minimize current density. While monopolar electrosurgical instruments can be useful for certain procedures, they can pose a risk of certain types of patient trauma, such as electrical burns, often due, at least in part, to the function of the return electrode. In bipolar electrosurgical instruments, one or more electrodes are electrically coupled to a source of electrical energy of a first polarity and one or more other electrodes are electrically coupled to a source of electrical energy of a second polarity opposite the first polarity. Bipolar electrosurgical instruments, which operate without a separate return electrode, can deliver electrical signals to a concentrated tissue area with reduced risk.

[0005] However, even when the surgical effect of a bipolar electrosurgical instrument is relatively focused, the surgical outcome often depends heavily on the skill of the surgeon. For example, delivering electrical energy for a relatively long period of time or delivering a relatively high-power electrical signal for a short period of time can result in thermal tissue damage and necrosis. The rate at which tissue achieves the desired coagulation or cutting effect upon application of electrical energy varies depending on the tissue type and can also vary based on the pressure applied to the tissue by the electrosurgical instrument. However, it can be difficult for a surgeon to assess how quickly to melt the desired amount of a mass of combined tissue types grasped with the electrosurgical instrument. Summary of the Invention [Problem to be solved by the invention]

[0006] According to various embodiments, an electrosurgical laparoscopic melter / sealer and dissector configured to simultaneously melt and cut tissue is provided. In various embodiments, the electrosurgical instrument or device has a first jaw and a second jaw opposing the first jaw for grasping tissue therebetween. The first jaw has an electrode and the second jaw has an electrode. The electrodes of the first and second jaws are positioned to melt and cut tissue between the first and second jaws using radio frequency energy, with opposing central portions of the first and second jaws being electrode-free.

[0007] In various embodiments, the electrosurgical instrument includes a first jaw having a first electrode with a first surface area that contacts tissue and a second electrode with a second surface area that contacts tissue. The first surface area is equal to the second surface area. The instrument further includes a second jaw facing the first jaw and coupled to the first jaw to grasp tissue therebetween. The second jaw has a third electrode with a third surface area that contacts tissue and a fourth electrode with a fourth surface area that contacts tissue. The third surface area is equal to the fourth surface area, and the fourth surface area is greater than the first surface area. The first and third electrodes are positioned on one side of a longitudinal axis to melt tissue located between the first and second jaws using radio frequency energy, and the second and fourth electrodes are positioned on the opposite side of the longitudinal axis to melt tissue located between the first and second jaws using radio frequency energy.

[0008] According to various embodiments, an electrosurgical system for simultaneously melting and cutting tissue is provided. The system, in various embodiments, includes an electrosurgical generator and an electrosurgical melter / sealer and dissector-type instrument or tool. The generator has an RF amplifier and a controller. The RF amplifier delivers RF energy through a removably coupled electrosurgical instrument, such as an electrosurgical melter and dissector, configured to melt and cut tissue using RF energy alone. The controller is configured to monitor the phase angle of the delivered RF energy, and the controller sends a signal to the RF amplifier to increase the voltage of the delivered RF energy if the monitored phase angle is greater than zero and increasing. In various embodiments, the controller sends a signal to the RF amplifier to stop the delivered RF energy if the monitored phase angle is decreasing.

[0009] Many of the attendant features of this invention will be readily appreciated as the same becomes better understood by reference to the foregoing and following detailed description when taken in conjunction with the accompanying drawings.

[0010] The present invention can be best understood when described in connection with the accompanying drawings, in which reference characters refer to the same parts throughout the figures. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a perspective view of an electrosurgical system according to various embodiments of the present invention; [Figure 2] 1A-1C are perspective views of electrosurgical generators according to various embodiments of the present invention; [Figure 3] 1A-1D are perspective views of electrosurgical instruments according to various embodiments of the present invention; [Figure 4] 1A-1D are perspective views of the distal end of an electrosurgical instrument according to various embodiments of the present invention. [Figure 5] 1A-1D are perspective views of the distal end of an electrosurgical instrument according to various embodiments of the present invention. [Figure 6]1A-1D are perspective views of the distal end of an electrosurgical instrument according to various embodiments of the present invention. [Figure 7] 1A-1D are perspective views of the distal end of an electrosurgical instrument according to various embodiments of the present invention. [Figure 8] 1A-1D are perspective views of the distal end of an electrosurgical instrument according to various embodiments of the present invention. [Figure 9] 1A-1D are perspective views of the distal end of an electrosurgical instrument according to various embodiments of the present invention. [Figure 10] 1A-1D are perspective views of the distal end of an electrosurgical instrument according to various embodiments of the present invention. [Figure 11] 1 is a graphical representation of sample experimental data relating to a fusing and cutting process using an electrosurgical instrument according to various embodiments of the present invention. [Figure 12] 1 is a graphical representation of sample experimental data relating to a fusing and cutting process using an electrosurgical instrument according to various embodiments of the present invention. [Figure 13] 1 is a graphical representation of sample experimental data relating to a fusing and cutting process using an electrosurgical instrument according to various embodiments of the present invention. [Figure 14] 1A-1C are cross-sectional views of the distal end of an electrosurgical instrument according to various embodiments of the present invention. [Figure 15] 1 is a flow chart illustrating the operation of an electrosurgical system according to various embodiments of the present invention. [Figure 16] 1 is a schematic block diagram of portions of an electrosurgical system according to various embodiments of the present invention; [Figure 17] 1 is a schematic block diagram of portions of an electrosurgical system according to various embodiments of the present invention; [Figure 18] 1 is a schematic block diagram of portions of an electrosurgical system according to various embodiments of the present invention; [Figure 19] 1 is a flow chart illustrating the operation of an electrosurgical system according to various embodiments of the present invention. [Figure 20] 1 is a flow chart illustrating the operation of an electrosurgical system according to various embodiments of the present invention. [Figure 21] 1 is a flow chart illustrating the operation of an electrosurgical system according to various embodiments of the present invention. [Figure 22] 1 is a graphical representation of sample experimental data for electrosurgical instruments according to various embodiments of the present invention; [Figure 23] 1 is a graphical representation of sample experimental data for electrosurgical instruments according to various embodiments of the present invention; [Figure 24] 1 is a graphical representation of sample experimental data for electrosurgical instruments according to various embodiments of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0012] Generally, a bipolar electrosurgical fuse / sealer and dissector-type instrument, tool, or tool is provided that is configured to simultaneously fuse and cut tissue captured between the jaws of the instrument. The jaws have individually positioned, shaped, and oriented electrodes along with compressible landing pads to simultaneously fuse and cut tissue. The bipolar surgical fuse and dissector may also fuse tissue or cut tissue separately. In various embodiments, tissue cutting is accomplished specifically without the use of a mechanical cutting blade, a specific or central cutting electrode, or the shearing force or action of scissors. Various embodiments of the instrument are provided for use in laparoscopic surgery with a maximum diameter of 5 mm and, thus, are insertable through a 5 mm trocar.

[0013] Additionally, generally speaking, an electrosurgical system is provided that includes an electrosurgical generator and a removably coupled electrosurgical instrument, e.g., a melting and dissection instrument, configured to optimally melt and cut tissue. RF energy is supplied by an electrosurgical generator, which is configured to provide the appropriate RF energy to melt and cut tissue. Various embodiments of the generator define the appropriate RF energy and delivery method for a particular coupled electrosurgical instrument, the particular tissue in contact with the instrument, and / or the particular surgical procedure. In operation, RF sealing or melting of tissue between the jaws is performed to reduce seal time, output voltage, output power, and / or thermal spread. Thus, power is effectively and consistently delivered to the tissue to heat the tissue over a temperature range at a specific rate found to be optimal for tissue impact.

[0014] 1 and 2, an exemplary embodiment of an electrosurgical system is shown, including an electrosurgical generator 10 and a removably connectable electrosurgical instrument 20. The electrosurgical instrument 20 may be electrically coupled to the generator via a cable connection 30 to a tool or instrument port 12 on the generator. The electrosurgical instrument 20 may have audible, tactile, and / or visual indicators to notify the user of certain predetermined conditions of the instrument, such as the start and / or completion of a melting or cutting operation. In other embodiments, the electrosurgical instrument 20 may be reusable and / or connectable to another electrosurgical generator for another surgical procedure. In some embodiments, a manual control, such as a hand or foot switch, may be coupled to the generator and / or instrument to enable predetermined, selective control of the instrument, for example, to initiate a melting or cutting operation.

[0015] According to various embodiments, the electrosurgical generator 10 is configured to generate radio frequency (RF) electrosurgical energy and receive data or information from an electrosurgical instrument 20 electrically coupled to the generator. The generator 10, in one embodiment, outputs RF energy (150 V and 5 A at 375 VA, 350 kHz) and, in one embodiment, is configured to calculate the phase angle or difference between the RF output voltage and the RF output current during operation or delivery of RF energy. The generator regulates the voltage, current, and / or power and monitors the RF energy output (e.g., voltage, current, power, and / or phase). In one embodiment, the generator 10 terminates the RF energy output under predetermined conditions, such as when an instrument switch is deasserted (e.g., a fuse button is released), a time value is met, and / or a change in the active phase angle and / or phase is equal to or exceeds a change in a certain phase and / or phase termination value.

[0016] Electrosurgical generator 10 has two novel bipolar tool ports 12, a standard bipolar tool port 16, and a power port 14. In other embodiments, the electrosurgical unit may have a different number of ports. For example, in some embodiments, the electrosurgical generator can have more than two or less than one novel bipolar tool port, more than two or zero standard bipolar tool ports, and more than two or zero power ports. In one embodiment, the electrosurgical generator has only two novel bipolar tool ports.

[0017] According to various embodiments, each novel bipolar tool port 12 is configured to couple to an electrosurgical instrument with an attached or integrated memory module. The standard bipolar tool port 16 is configured to accept non-specific bipolar electrosurgical tools that are different from the novel bipolar electrosurgical instruments connectable to the novel bipolar tool port 12. The power port 14 is configured to accept or connect to non-specific bipolar electrosurgical tools and direct current (DC) accessory devices that are different from the novel electrosurgical instruments. The power port 14 is configured to provide a DC voltage. For example, in some embodiments, the power port 14 can provide approximately 12 volts DC. The power port 14 can be configured to power a surgical accessory, such as a ventilator, pump, light, or other surgical accessory. Thus, in addition to replacing an electrosurgical generator for a standard or non-specific bipolar tool, the electrosurgical generator can replace a power source for a surgical accessory. In some embodiments, replacing an existing generator and power supply with an electrosurgical generator can reduce the amount of storage space required on storage racks, cards, or shelves for the many mains cords required within a surgical or operating workspace.

[0018] In one embodiment, coupling a non-specific bipolar tool into a standard bipolar port does not cause the generator to actively check for the tool. However, the generator recognizes the connection so that it can display information about the non-specific bipolar tool. According to various embodiments, the generator recognizes the instrument connection status for each of the advanced tool ports 12 and authenticates the connected instrument before receiving an RF energy activation request (e.g., activation of an instrument switch, e.g., a fuse button). In one embodiment, the generator reads authenticated data from the connected instrument and electrical control values ​​from the authenticated and connected instrument (e.g., voltage level setting, current level setting, power level setting, active phase angle level setting, RF energy output activation timing limit, instrument short circuit limit, instrument open circuit limit, instrument model / identification, RF energy output line configuration, switch state command configuration, and / or combinations thereof).

[0019] According to various embodiments, the electrosurgical generator 10 can include a display 15. The display can be configured to indicate the status of the electrosurgical system, including, among other information, the status of one or more electrosurgical instruments and / or accessories, connectors, or connections thereto. In some embodiments, the display can comprise a multi-line display, such as an LCD panel display, capable of providing textual and graphical information, which in some embodiments can be illuminated via a backlight or sidelight. In some embodiments, the display can comprise a multi-color display configured to display information regarding a particular instrument electrically coupled to the electrosurgical generator and a color corresponding to a particular surgical procedure (e.g., cutting operations displayed in yellow text and graphics, melting or welding operations displayed in purple, and coagulation operations displayed in blue, with bloodless transection operations displayable in yellow and blue).

[0020] In some embodiments, the display may be configured to simultaneously display status data for multiple instruments electrically coupled to the electrosurgical generator and / or partitioned to display status information for each instrument connected to a corresponding tool port. A visual indicator, such as a status bar graph, may be used to illustrate the percentage of total available electrical energy to be applied to a bipolar electrosurgical instrument when activated. In various embodiments, an electrosurgical instrument operable to cut, seal, coagulate, or melt tissue may have three colored displays or bar graphs. In some embodiments, a user can toggle the display between providing the status of multiple electrically connected machines and a single electrically connected machine. According to various embodiments, once an instrument and / or accessory is connected and / or detected, a window in the user interface display opens to indicate the connection type and status of the instrument.

[0021] According to various embodiments, the electrosurgical generator may include a user interface, such as a plurality of buttons 17. These buttons allow user interaction with the electrosurgical generator, such as requesting an increase or decrease in electrical energy delivered to one or more instruments coupled to the electrosurgical generator. In other embodiments, the display 15 may be a touchscreen display, thus incorporating data display and user interface functions. According to various embodiments, the surgeon may set voltage settings via the user interface by selecting one to three levels. For example, at level 1, the voltage is set to 110 V; at level 2, the voltage is set to 100 V; and at level 3, the voltage is set to 90 V. For all three levels, the voltage is set to 5 amps and the power is set to 300 VA. In other embodiments, the voltage is preset or defaults to a particular level, such as level 2. In other embodiments, like the current and power settings, the voltage setting is not user adjustable to simplify operation of the generator, and therefore a predetermined default voltage setting is utilized, for example, the voltage is set to 100V.

[0022] In one embodiment, the electrosurgical tool or instrument 20 can further include one or more memory modules. In some embodiments, the memory contains operational data relating to this and / or other instruments. For example, in some embodiments, the operational data can include information regarding electrode configurations / reconfigurations, instrument usage, operating times, voltage, power, phase and / or current settings, and / or specific operating states, conditions, scripts, processes, or procedures. In one embodiment, the generator initiates reads from and / or writes to the memory module.

[0023] In one embodiment, each new bipolar electrosurgical instrument is accompanied by a memory module and / or integrated circuitry that provides instrument authentication, configuration, expiration, and logging. Binding of such an instrument into a receptacle or port initiates the instrument verification and authentication process. Instrument authentication, in one embodiment, is provided via a challenge-response scheme and / or a stored secret key that is also shared by the generator. Other parameters include a hash key for integrity checking. Usage is logged in the generator and / or on the instrument's integrated circuitry and / or memory. In one embodiment, errors may result in non-logged usage. In one embodiment, logging is set in binary and interpreted by the offline instrument or via the generator.

[0024] In one embodiment, the generator monitors instrument expirations using a time measurement component. Such a component utilizes a polling oscillator or timer or real-time calendar clock that is configured at boot time. Timer interrupts are handled by the generator and can be used by scripts for timeout events. Logging also utilizes a timer or counter to time-stamp logged events.

[0025] According to various embodiments, the generator provides the ability to read the phase difference between the voltage and current of RF energy delivered through a connected electrosurgical instrument while the RF energy is active. The phase reading is used to detect different states during the melting or sealing and cutting process while the tissue is being melted.

[0026] In one embodiment, the generator logs details regarding usage in a downloadable internal log. The generator has memory for storing code and device performance. The generator has programmable memory containing instructions related to specific device performance. The memory holds, for example, serial numbers and device usage parameters. The generator stores information regarding the type of device connected. Such information includes, but is not limited to, a timestamp, the number or duration of use of the connected device, the power settings of each device, and any changes made to the default settings, along with an identifier for the device, such as the serial number of the connected device. In one embodiment, the memory holds data for approximately two months, approximately 10,000 device uses, or up to 150 logged activations, and is configured to overwrite itself as needed.

[0027] The generator, according to various embodiments, does not monitor or control the current, power, or impedance. The generator can adjust and match the voltage. The delivered electrosurgical power is a function of the applied voltage, current, and tissue impedance. The generator can affect the delivered electrosurgical power through adjusting the voltage. However, increasing or decreasing the voltage does not necessarily increase or decrease the delivered electrosurgical power. Power reactions are caused not by the generator supplying the power, but by the power or tissue conditions interacting with the tissue without any control by the generator.

[0028] Once the generator delivers electrosurgical power, it does so continuously, for example, every 150 ms, until a failure occurs or a specified phase parameter is reached. In one example, the jaws of the electrosurgical instrument can be opened, thus allowing compression to be released at any time before, during, and after application of electrosurgical power. The generator also, in one embodiment, does not pause or wait a specified duration or predetermined time delay to initiate termination of electrosurgical energy.

[0029] 3-14, according to various embodiments, a bipolar melt and dissect electrosurgical instrument 20 is provided. In the illustrated embodiment, the instrument 20 includes an actuator 24 coupled to an elongated, rotatable shaft 26. The elongated shaft 26 has proximal and distal ends, with a central longitudinal axis defined between the distal and proximal ends. The shaft 26 includes a jaw 22 at its distal end and an actuator at its proximal end. In one embodiment, the actuator is a handle, such as a pistol grip. The shaft 26 and jaw 22 are sized and shaped, in one embodiment, to fit within a 5 mm diameter trocar cannula or access port.

[0030] The actuator 24 includes a movable handle 23 and a stationary handle or housing 28, with the movable handle 23 coupled to and movable relative to the stationary housing. According to various embodiments, the movable handle 23 is slidably and pivotably coupled to the stationary housing. In operation, a user, e.g., a surgeon, manipulates the movable handle 23 to actuate the jaws, e.g., selectively open and close the jaws. According to various embodiments, the actuator 24 includes a force adjustment mechanism configured such that, in the closed configuration, the jaws 22 deliver a gripping force between a predetermined minimum force and a predetermined maximum force.

[0031] As part of the force adjustment mechanism, the movable handle 23 is coupled to the stationary handle at two sliding pivot locations to form the force adjustment mechanism. The movable handle has a first end with a gripping surface formed thereon and a second end opposite the first end. The movable handle is coupled to a pin adjacent the second end. In some embodiments, the movable handle can be integrally formed with a protrusion extending therefrom to form the pin surface. In other embodiments, the pin can be press-fit into a hole in the movable handle. The pin can be received in a slot in the stationary housing, for example, a corresponding slot formed in the right and / or left handle frame of the stationary housing. In some embodiments, the slot can be configured to define a desired actuation handle path, for example, a curved or angled path, when the actuation handle is moved from a first position corresponding to an open jaw to a second position corresponding to a closed jaw. The force adjustment mechanism includes a biasing member, for example, a tension spring, that biases the pin in a proximal direction. In operation, when a predetermined force is exerted by movement of the movable handle, the biasing force exerted by the spring is overcome and the second end of the movable handle can translate distally as a whole, guided by the pin in the slot.

[0032] According to various embodiments, the movable handle is slidably and pivotally coupled to the stationary housing 28 at a location between the first and second ends of the actuation handle. An actuator member, e.g., a pull block, is coupled to the actuation handle. When the movable handle is moved proximally, the pull block also moves proximally and longitudinally, closing the jaws 22 and thereby clamping any tissue between them. According to various embodiments, the pull block is rectangular with open top and bottom faces and a closed proximal end. The movable handle passes through the top and bottom faces of the pull block. An edge of the movable handle abuts the proximal end of the pull block so that movement of the movable handle relative to the stationary housing moves the pull block longitudinally. The distal end of the pull block, in one embodiment, is coupled to an actuation shaft, e.g., a pull tube, bar, or rod, which may extend longitudinally along the elongated shaft 26. Thus, in operation, movement of the movable handle from a first position to a second position causes longitudinal translation of the pull block within the stationary housing, which in turn causes corresponding generally linear translation of the pull tube along the longitudinal axis relative to the elongated shaft 26. This pull tube movement can control the relative movement of the jaws 22.

[0033] According to various embodiments, the actuator 24 has a latch mechanism that positions the movable handle 23 in a second position relative to the stationary housing 28. In various embodiments, the movable handle has a latch arm that engages a mating latch housed within the stationary handle to hold the movable handle in the second or closed position. In various embodiments, the actuator has a wire harness that includes insulated individual wires or leads housed within a single sheath. The wire harness can exit the stationary housing at its underside and form part of a cable-type connection. The wires within the harness can provide electrical communication between the instrument and the electrosurgical generator and / or its accessories or attachments.

[0034] According to various embodiments, the actuator has one or more leads attached to a rotational coupling clip configured to allow infinite rotation of the shaft. In various embodiments, a switch is connected to a user-operated activation button 29, which is activated when the activation button is pressed. In one aspect, once activated, the switch completes a circuit by electrically coupling at least two leads to one another. Thus, an electrical pathway is then established from the electrosurgical generator to the actuator to deliver RF energy to the leads attached to the rotational coupling clip.

[0035] In one embodiment, the actuator includes a rotation shaft assembly including a rotation knob 27 mounted on the outer cover tube of the elongated shaft 26. The rotation knob allows a surgeon to rotate the instrument shaft while grasping the actuator 24. According to various embodiments, the elongated shaft 26 includes an actuation tube that couples the jaws 22 to the actuator. In various embodiments, the actuation tube is housed within the outer cover tube. While the actuation tube is illustrated as a generally tubular member that is fittable within the outer cover tube, other embodiments may use non-tubular actuation members, such as shafts, rigid bands, etc., which may be disposed within the outer cover tube in certain embodiments.

[0036] According to various embodiments, a rotating shaft assembly is attached to the distal end of the outer cover tube, and the rotating shaft assembly includes two mating hubs and a conductive sleeve. The hubs engage the outer cover tube via a snap fit. In other embodiments, the hub can be a one-piece structure and can be configured to interface with a mating feature on the outer cover tube. The conductive sleeve can be attached to a proximal portion of the assembled hub after the assembled hub is attached to the outer cover tube. When the conductive sleeve is attached to the rear of the assembled hub, it captures the exposed end of the insulated wire. In the illustrated embodiment, the insulated wire extends from its capture point, located under the conductive sleeve, through a slot in the actuator tube, and then into the protective sleeve. The protective sleeve and insulated wire extend distally within the actuator tube toward the jaws. In other embodiments, the insulated wire can be integrally formed with the protective sheath, in which case there is no separate protective sleeve within the actuator tube.

[0037] Jaws 22 are attached to the distal end of the elongate shaft and comprise a first jaw 70 and a second jaw 80. In one embodiment, a jaw pivot pin pivotally couples the first and second jaws, allowing the first jaw to move and rotate relative to the second jaw. In various embodiments, one jaw is fixed relative to the elongate shaft, and the opposing jaw pivots relative to the fixed jaw between open and closed positions. In other embodiments, both jaws can be pivotally coupled to the elongate shaft, allowing both jaws to rotate relative to each other.

[0038] The jaw geometry provides specific pressure profiles and specific current densities at specific locations to produce the desired melting / sealing and cutting effect. In operation, the temperature required to achieve sealing and division is minimized while maximizing protein cross-linking within the vascular structure, thereby maximizing the effectiveness of the tissue melting / sealing and division.

[0039] According to various embodiments, the phase angle and / or the rate of change of the phase angle are monitored to monitor the temperature of the biological reaction. The phase angle has been found to provide an indication of the temperature of the biological reaction and indicate that tissue division has occurred. According to various embodiments, the electrosurgical instrument uses electrosurgical bipolar RF energy to cut and melt tissue located between the jaws when opening and closing and / or in contact with the lower jaw when the jaws are opened and closed. In one embodiment, the temperature of the tissue is monitored during the sealing and / or dividing cycles.

[0040] The novel bipolar electrosurgical instruments of various embodiments use bipolar RF energy to both seal or melt and divide or cut tissue. Thus, while applying the energy necessary to divide the tissue, the instruments maintain tissue cellular structure adjacent to the division area. Other RF dissection instruments use a local arc or spark gap to vaporize the tissue and achieve the incision. This may be acceptable for straight tissue incisions because the surrounding area is not sealed or melted, unlike the melting and dissection instruments and systems of various embodiments of the present invention.

[0041] Various embodiments of the novel bipolar electrosurgical instrument also take into account the high heat associated with tissue vaporization or tissue cutting. Therefore, various embodiments of the instrument utilize temperature control to minimize the energy required to achieve tissue division. By minimizing the energy required, temperatures are lower during the reaction, and cellular structures are less likely to be destroyed due to the high energy output.

[0042] Preserving the cellular structure of working tissue is necessary when simultaneously fusion and dissection or division, as sealing must occur adjacent the incision area. Also, the addition of open cutting and sealing modes correspondingly reduces the number of instruments or instrument exchanges used in performing a surgical procedure, or all of these functions of individual such instruments are included in a single, novel bipolar laparoscopic instrument.

[0043] In various embodiments, the electrosurgical instrument has movable jaws capable of capturing tissue therebetween. In one embodiment, the jaws include at least one upper jaw that closes over a stationary lower jaw. According to various embodiments, the upper jaw includes a rigid upper jaw member 41, an upper conductive pad 42, a rigid insulating pad 43, electrical wires 44, and a compressible landing pad 45, all of which are bonded together using an insert molding process, such that the upper jaw is provided as a single structure or assembly, as shown in FIG.

[0044] The rigid upper jaw member and the upper conductive pad are both active electrodes with opposing properties. The compressible landing pad provides a surface with a specific spring constant to ensure contact and pressure occurs between the landing pad and the length of the lower jaw. The upper conductive pad 42 is electrically isolated from the rigid upper jaw member 41 by the landing pad 45 and the insulating pad 43. In various embodiments, the upper jaw is made of stainless steel and is more rigid than the landing pad 45. In various embodiments, the landing pad 45 is made of silicone and is more compliant than the upper jaw member 41 or the conductive pad 42. In various embodiments, the insulating pad is made of a non-conductive material and is as stiff or stiffer than the upper jaw member 41 or the conductive pad 42. In various embodiments, the upper jaw member 41 and the conductive pad are made of the same material.

[0045] The upper jaw member 41 and the conductive pad have lower outer surfaces positioned to contact tissue. The lower surfaces are angled or sloped, mirror images of each other, and such positioning or orientation facilitates focusing of current density and fixation of tissue. The compressible landing pad 45 has a lower surface positioned to contact tissue and / or the lower jaw. In the illustrated embodiment, the landing pad is flat and not parallel to the sloped lower surfaces of the upper jaw member and conductive pad 42. The positioning and orientation of the landing pad's lower surface aids in focusing of current density, aids in fixation of tissue, and facilitates electrodissection of tissue. The spring constant of the landing pad, in various embodiments, is predetermined to provide optimal pressure or force to cause or facilitate electrosection of tissue.

[0046] The lower jaw includes a rigid lower jaw member 52, a lower conductive pad 53, a cutting electrode 55, two rigid insulators 54, 56, and two electrical wires, one to the conductive pad and one to the cutting electrode, all bonded together using an insert molding process and thus provided as a single structure or assembly as shown in FIG. 7 according to various embodiments of the present invention. The rigid lower jaw member 52, the lower conductive pad 53, and the cutting electrode 55 are all active electrodes or function as active electrodes. The lower conductive pad 53 and the cutting electrode 55 have the same polarity and are electrically isolated from the rigid lower jaw member, which has the opposite polarity, by the two rigid insulators 54, 56.

[0047] The lower jaw member 52 and the conductive pad 53 have upper outer surfaces positioned to contact tissue. The upper surfaces are angled or sloped and are mirror images of each other, facilitating current density concentration and tissue fixation. In various embodiments, the lower jaw is made of stainless steel and is approximately as stiff as or stiffer than the conductive pad 53. In various embodiments, the rigid insulators 54, 56 are made of a non-conductive material and are approximately as stiff as or stiffer than the lower jaw member 52 or conductive pad 53. In various embodiments, the lower jaw member 52 and the conductive pad 53 are made of the same material.

[0048] Various embodiments of the overall jaw structure are shown in cross section in FIG. 8 to demonstrate the interplay of upper and lower jaw geometry (e.g., shape, size, material, and any combination thereof for optimal fusion and dissection). In operation, conductive pads 42 and 53 are of the same polarity. Upper and lower jaw members 41, 51, and 52 are of the same polarity but of opposite polarity to conductive pads 42 and 53. In one embodiment, cutting electrode 55 is active only during the open cutting and fusion operation, and this cutting electrode is of opposite polarity to lower jaw member 52. As shown, landing pad 45 interferes with and compresses against lower jaw member 52 and conductive pad 53 during jaw closure. Tissue (not shown) captured between the lower and upper jaws is also compressed between landing pad 45, lower jaw member 52, and conductive pad 53.

[0049] The polarity of each electrode is set to produce the appropriate RF energy and heating due to the current flowing between them. As shown in FIG. 9, the direction of current flow allows for heating between the conductive pad and the jaw members, as illustrated by arrow 101, and allows for end-to-end heating on the lower jaw structure, as illustrated by arrow 102. End-to-end heating on the lower jaw structure is used to divide the tissue, as illustrated by arrow 102. To divide the tissue under the middle of the jaws, the tissue is heated to a temperature of 60°C to 100°C to denature the collagen present in the tissue. Once denatured, the collagen becomes gelatinous.

[0050] When the tissue is in a glue-like or gelatinous state, the spring constant and interference of the silicone landing pad cause mechanical separation of the tissue, as illustrated by arrow 103 in FIG. 10 . In various embodiments, the spring constant is predetermined to optimize tissue separation through interference with the pad and lower jaw, causing the landing pad to contract a predetermined distance or amount to accommodate the tissue between the pad and lower jaw with minimal or no effect on adjacent tissue. Thus, the electrode configuration allows for simultaneous heating of the sealing region (the region between the conductive pad and the jaw members) and the cutting region (the end-to-end current flow region on the lower jaw). Collagen denaturation is also a mechanism used to create tissue sealing or melting. While sealing utilizes the same temperatures as cutting (60°C-100°C), the jaw seal gap between the conductive pad and the jaw members creates a mold for re-crosslinking of the seal once RF application ceases. Notably, by reaching high temperatures quickly, cellular structures may be disrupted due to rapid heating of intercellular moisture. Thus, a gradual increase in temperature and a long residence time within the appropriate temperature range allows for complete denaturation of the collagen.

[0051] In various embodiments, the tissue phase angle and / or rate of change of the phase angle are monitored to achieve the appropriate tissue temperature to produce an associated tissue effect, e.g., a gradual increase and / or longer dwell time. FIGS. 11-13 are graphical illustrations of exemplary sealing and division cycles, in accordance with various embodiments. Also shown, phase 111g is plotted relative to other tissue readings or indicators, e.g., voltage 111a, power 111b, impedance 111c, energy 111d, temperature 111e, and current 111f. Additionally, while shown in FIGS. 11-13, in various embodiments, the generator is configured not to measure or calculate one or more of the indicators or readings, e.g., temperature or energy, to reduce operational and power costs, power consumption, and / or generator part count. Additional information or readings are generally provided or shown for related purposes.

[0052] 11-13, the temperature of the tissue 111e between the jaws increases from the onset of RF energy to the point of highest phase angle. At this point of highest phase angle (or inflection point in the rate of change of phase angle) 155, a temperature plateau 150 continues momentarily (approximately 0.75 seconds) followed by the next highest state 152, even as the voltage is reduced.

[0053] Due to the behavior of the temperature profile, it is noted that momentary temperature plateaus may be due to changes in the state of water or moisture present in the tissue. Once water begins to boil, the temperature does not increase until the liquid water is converted to steam. Therefore, the calculation of temperature 111e may not be based on phase angle 111g. The temperature before the maximum phase angle is associated with steady heating to 100°C. The temperature plateau is associated with a sudden decrease in phase angle that may be associated with 100°C and two states of water. Because liquid water is highly conductive and steam is not, this phase transition may be another indicator of the state of water. Once the temperature continues to increase above 100°C (152) and continues to increase beyond the second phase angle inflection point 160, it is noted that the majority of the water has converted to steam.

[0054] Another point of interest that can be seen in RF power is the sudden spike 170 in power 111b and current 111f during boiling of the water portion of the RF application, as shown, for example, in FIG. 13. This spike can be attributed to tissue splitting during the sealing or melting process. This increase in power and current can be attributed to tissue no longer being present under the insulating portions of the jaws, such as the landing pads. At this point, the jaws are more closed and energy is only passing through the sealing surface.

[0055] Since the temperature required to denature collagen begins at 60° C., the application of energy is optimized to maximize the time prior to 100° C. This results in complete and thorough denaturation of the collagen. Therefore, all seals must be completed prior to the spike 170 in power and current to ensure that the seals are completed prior to splitting.

[0056] According to various embodiments, the electrosurgical instrument also has the ability to cut tissue using RF energy, and in one embodiment, utilizing only the lower jaw when the jaws are in the fully open position, without the cooperation of the upper jaw or when tissue is not trapped between the upper and lower jaws but is in contact with the lower jaw. Figure 14 shows the direction of current flow (arrow 140) from the cutting electrode 55 to the rigid lower jaw member 52.

[0057] To achieve tissue cutting, a high potential difference is created between the cutting electrode 55 and the lower jaw member 52. This results in vaporization of the tissue due to heat created by localized arcing around the cutting electrode. When high temperatures are encountered, the insulating material used to insulate the cutting electrode in one embodiment can withstand or perform well at high temperatures. Also, at high potential differences, the insulator, in one embodiment, has a high dielectric strength. The potential difference exceeds 400 V-peak to achieve sufficient arcing. However, the actual potential difference is directly related to the spacing between the cutting electrode and the lower jaw member.

[0058] Arc suppression is another issue, resulting in rapid correction of RF waveform distortion due to arcing and / or limiting power output to prevent degradation of materials used in jaw construction. If an arc lasts longer than 100 microseconds, the risk of instrument degradation increases. Also, due to the very high heat associated with local arcing, RF energy application according to various embodiments includes waveforms with a predetermined duty cycle or high crest factor. It has been found that the crest factor associated with a sinusoidal waveform, when allowed to maintain a constant output, inevitably results in instrument degradation. Manipulating the duty cycle or crest factor reduces the average output power throughout instrument operation.

[0059] Various embodiments of the electrosurgical instrument also use RF energy, and in one embodiment, only with the jaws in the fully open position, utilizing only the lower jaw, to melt tissue without the cooperation of the upper jaw or with tissue not trapped between the upper and lower jaws but in contact with the lower jaw. Figure 14 shows an exemplary direction of current flow from the cutting electrode 55 to the rigid lower jaw member 52.

[0060] According to various embodiments, a low potential difference is maintained between the cutting electrode 55 and the lower jaw member 52 to cause tissue coagulation. The potential difference is set to less than 100 V peak to prevent local arcing, but the actual potential is directly related to the spacing between the cutting electrode and the lower jaw member. Tissue coagulation is caused by heat generated by RF current between the two electrodes.

[0061] In one embodiment, an insulated wire 44 is routed to electrically couple the first jaw to a wiring harness within the actuator. The insulated wire extends from the distal end of a protective sleeve housed at the proximal end of the second jaw and into the first jaw. The first jaw may have a slot positioned to receive the insulated wire. The insulated wire then passes through a hole in the first jaw and into a slot in the non-conductive portion. The insulated wire then extends to the distal end of the non-conductive portion, through which it passes down to the conductive pad.

[0062] In some embodiments, the geometry of the electrodes on or at the conductive pads of the jaws is such that the sealing area completely encompasses the distal portion of the blade cutting path. According to various embodiments, the dimensions of the jaw surfaces are appropriately proportioned for optimal pressure exerted on the tissue between the jaws due to the potential force that the force adjustment mechanism can generate. The surface area is also electrically significant relative to the surface area in contact with the tissue. This ratio of surface area and tissue thickness is optimized with respect to its relationship to the electrical relative properties of the tissue.

[0063] In one embodiment, as shown in FIG. 15 , an electrosurgical process, such as a tissue melting process, begins by pressing a switch on the instrument or tool (151), thereby initiating an initial measurement sequence. With the tool switch engaged, the generator takes an initial measurement of the tissue (open, short, etc.) (152) and initiates or prevents delivery of RF energy (153) based on the initial measurement. According to various embodiments, the generator measures tool and / or tissue impedance and / or timing and / or determines whether the phase angle is within acceptable limits. In one embodiment, the generator measures the tissue between the electrodes of an electrosurgical instrument connected to the generator that utilizes RF energy in a low-energy range (e.g., voltages of about 1-10 volts) that does not produce psychological effects (i.e., passive measurements). In various embodiments, the generator uses the initial impedance measurement to determine whether the instrument is shorted, faulty, open, etc. Based on a positive result of the initial check, the generator enables delivery of RF energy from the generator to the electrosurgical instrument and ultimately to the tissue 154. After RF power is turned on, and as RF power is continuously delivered by the generator, the generator monitors 155 the phase angle or phase angle difference and / or change between the power and voltage of the delivered RF energy.

[0064] At a predetermined or pre-determined time, condition, or threshold (156), delivery of RF energy is stopped (157), providing an audible and / or visual signal indicating that the tissue has melted (or that an error (e.g., shorted electrode) and / or unexpected condition (e.g., unexpected switch release but acceptable condition) has occurred). According to various embodiments, the predetermined time, condition, or threshold and / or initialization check is determined based on a device algorithm or script provided for the connected electrosurgical instrument, procedure, or preference. According to various embodiments, the measured tissue acceptability and conductivity or initial phase shift results are used to determine an endpoint for the connected instrument.

[0065] 16 , in one embodiment, electrosurgical generator 10 is connected to an AC mains input, and power supply 141 converts the AC voltage from the AC mains input to a DC voltage for powering the various circuits of the generator. The power supply also provides the DC voltage to RF amplifier 142, which generates RF energy. In one embodiment, RF amplifier 142 converts 100 VDC from the power supply into a sinusoidal waveform at a frequency of 350 kHz, which is transmitted through the connected electrosurgical instrument. RF sense circuit 143 measures / calculates the voltage, current, power, and phase at the generator's output, and RF energy within the generator is supplied to the connected electrosurgical instrument 20. The measured / calculated information is transmitted to controller 144.

[0066] In one embodiment, the RF sense analyzes the measured AC voltage and current from the RF amplifier and generates DC signals for control signals sent to the controller for further processing, including voltage, current, power, and phase. In one embodiment, the RF sense circuit 143 measures the output voltage and current and calculates the root mean square (RMS) of the voltage and current, the apparent power of the RF output energy, and the phase angle between the voltage and current of the RF energy being delivered through the connected electrosurgical instrument. In particular, the voltage and current of the output RF energy are processed by the RF sense analog circuitry to generate real and imaginary components of both the voltage and current. These signals are processed by a field programmable gate array (FPGA) to provide different measurements of the voltage and current, including the AC signal, the phase shift between the voltage and current, and an RMS measurement of the power. Thus, in one embodiment, the output voltage and current are measured analog, converted to digital, and processed by the FPGA to calculate the RMS voltage and current, the apparent power, and the phase angle between the voltage and current, and then the output voltage and current are converted back to analog for the controller.

[0067] For each instrument port, there is one pair of signals for the voltage and one pair of signals for the current coming from the RF amplifier 142. In one embodiment, the generator has two redundant RF sense circuits 143a, 143b that measure the voltage and current for each instrument at different locations on the RF amplifier. The first RF sense circuit senses the current sent through the connected electrosurgical instrument on either Instrument Port 1 or Instrument Port 2 via a sense resistor and senses the voltage measured before and after the return to the output on either Instrument Port 1 or Instrument Port 2. The second RF sense circuit senses the current returned from the connected electrosurgical instrument on either Instrument Port 1 or Instrument Port 2 via a sense resistor and senses the voltage 146a, 146b measured before and after the output to the return on either Instrument Port 1 or Instrument Port 2. The voltage input signal is a high-voltage sinusoidal waveform at 350 kHz that is attenuated and AC-coupled by a voltage divider and inverting filter to remove DC bias on the signal. Inverting filters are used because the voltage and current inputs are 180° out of phase when measured with opposite polarities. For each voltage input signal, two separate inverted and non-inverted voltage sense signals are generated. In one embodiment, a differential voltage measurement is made between the voltage input signals to generate two separate pairs of inverted and non-inverted current sense signals. The current input signal represents the voltage across a shunt resistor on the RF amplifier, where this voltage is proportional to the current flowing through the shunt resistor. The current input signal is a low-voltage sinusoidal waveform at 350 kHz that is amplified using a non-inverting filter to remove DC bias on the signal. RF Sense generates signals similar to the result of multiplying each voltage and current signal by a predetermined reference signal. Thus, RF Sense produces non-inverted voltage and current sense signals when the waveform is positive, inverted voltage and current sense signals when the waveform is negative, and a ground signal when the waveform is zero.

[0068] According to various embodiments, the RF sense receives four reference synchronization signals provided by the controller via an RF amplifier. The synchronization signals are 350 kHz pulse signals with the same duty cycle but different phase shifts, which in one embodiment are 90° out of phase with each other. Two of the synchronization signals are used to generate in-phase waveforms to generate the real component of the input waveform, and two other synchronization signals are used to generate quadrature waveforms to generate the imaginary component of the input waveform. These signals are further processed to generate control signals for multiple switches, the outputs of which are combined to generate the signal output. In one embodiment, the control signals for the switches determine which input signals pass to the signal output. According to various embodiments, a first combination allows non-inverted voltage and current sense signals to pass, which represents or resembles multiplying the sense signals with a positive pulse. A second combination allows inverted voltage and current sense signals to pass, which represents or resembles multiplying the sense signals with a negative pulse. A third combination allows a ground signal to pass, thereby producing a zero voltage output representing or similar to multiplying the sense signal by zero. Each output is fed to a low-pass filter, which generates a DC voltage corresponding to the real or imaginary component of the sensed signal. These signals are fed to an ADC, which sends a digital signal to the FPGA.

[0069] In one embodiment, the controller 144 controls the RF amplifier 142 to affect the output RF energy. For example, the controller uses information provided by the RF sense 143 to determine whether RF energy should be output and when to stop the output of RF energy. In one embodiment, the controller compares predetermined phase thresholds based on the particular tissue in contact with the connected electrosurgical instrument 20 to determine when to stop the output of RF energy. In various embodiments, the controller performs the ablation process, which is described in detail below, and in some embodiments, the controller receives commands and settings or script data for implementing the ablation process from data sent from the electrosurgical instrument.

[0070] According to various embodiments shown in FIG. 17, the generator has six major subsystems or circuit modules, including a system power supply or power supply 145, a controller 144, a front panel interface 146, an advanced bipolar instrument interface 147, an RF amplifier 142, and an RF sense 143. According to various embodiments, one or more of the circuits may be combined or integrated with the other circuits. The power supply 145 is configured to provide a DC voltage along with control signals to all other circuits or subsystems to control the power supply output. The power supply receives an AC power input that is 90-264 VAC, 47-63 Hz, and in one embodiment, the power supply has an integrated or separate switch configured to connect or disconnect the AC power input to the generator. The controller supports instrument connections for the user interface 121 and electrosurgical instruments 1, 2 connected to the electrosurgical generator via the front panel interface (FPI) and advanced bipolar instrument interface (ABDI).

[0071] RF amplifier 142 generates high-power RF energy that passes through the connected electrosurgical instrument, and in one example, for tissue ablation. According to various embodiments, the RF amplifier converts a 100 VDC power source into a high-power sinusoidal waveform having a frequency of 350 kHz that is delivered to ABDI 147 and ultimately to the connected electrosurgical instrument. RF sense 143 interprets the measured AC voltage and current from RF amplifier 142 and generates DC control signals that are interpreted by controller 144, including voltage, current, power, and phase.

[0072] The generator has multiple dedicated connection receptacles, in the illustrated embodiment, Instrument Port 1 and Instrument Port 2, that are used exclusively for connection to novel bipolar instruments, such as the electrosurgical ablation instrument described in detail below. Each dedicated receptacle contains an array of spring-loaded probes or pogo pins. In various embodiments, the generator has circuitry that detects the presence of novel bipolar instruments prior to energizing the active output terminals at the receptacles.

[0073] The front panel interface (FPI) 146 is configured to drive the display, instrument signals from the controller, and LED backlighting for the front panel buttons. The FPI is also configured to provide power isolation via a regulator and functionality for the front panel switches / buttons. In one embodiment, the ABDI 147 is used as a pass-through connection to the instrument via the FPI. The FPI also allows connection of the controller 144 and the connected electrosurgical instrument via the ABDI. This instrument interface, in one embodiment, is electrically isolated from the rest of the FPI. In various embodiments, the interface includes lines to read and write FRAM® on the new bipolar instruments, read the trigger switch, and / or read the signal indicating that the instrument is connected. In one embodiment, an instrument memory circuit is provided that utilizes the controller's serial peripheral interface (SPI) to read and write to the FRAM on the new bipolar instruments. In one embodiment, a microcontroller is used instead of the FRAM, and the interface includes an interrupt line, so all information is communicated between the electrosurgical instrument and the generator via the digital interface. The FPI provides isolation for SPI signals to and from new bipolar instruments via ABDI. In one embodiment, the isolated interface for SPI signals is shared by two new bipolar instruments, and a port pin is used as a chip select.

[0074] According to various embodiments, the generator has an SPI communication bus that allows the controller to have a bidirectional communication relationship with a complex programmable logic device (CPLD) and an RF sense FPGA. In various embodiments, the FPI provides an SPI interface between the controller and a connected instrument via the ABDI connector to communicate with the FRAM on new bipolar instruments. The FPI also provides electrical isolation for low voltage signals from the controller and the ABDI. The instrument interface on the ABDI is configured to deliver RF energy to a connected instrument along with isolated interface communication for the SPI signals. In one embodiment, the ABDI provides a connection for a signal from the instrument indicating that the instrument is connected.

[0075] The FPI-ABDI interface provides power to instruments connected to the generator, enables SPI communication between the controller and the instruments, provides instrument switch signals from the instruments to the controller, and provides instrument connection signals from the instruments to the controller. The ABDI provides RF energy to each connected new bipolar instrument via a separate pogo pin array. The FPI provides signals from the FPI and RF amplifier, low voltage power, and high voltage RF power via the pogo pin array to the connected instruments through the ABDI connector.

[0076] According to various embodiments, the operational engine allows the generator to be configured to accommodate a variety of operational plans, including, but not limited to, many different electrosurgical tools, surgical procedures, and preferences. The operational engine receives and interprets data from external sources, thereby specifically configuring the operation of the generator based on the received data.

[0077] The operational engine receives configuration data from an appliance database script file that is read from a memory device on the appliance plug. The script defines the state logic used by the generator. Based on the states defined by the generator and measurements made by the generator, the script can define or set output levels and shutoff criteria. The script includes trigger events or indicators, including, for example, in one embodiment, an indication of a short circuit condition if the measured phase is greater than 70° or an indication of an open circuit condition if, for example, the measured phase is less than -50°.

[0078] In one embodiment, the operational engine provides system states and user states. System states are predefined states that control or manage certain predefined or predetermined operating conditions of the generator, such as a state that successfully applies RF energy or indicates an error. System states, in one embodiment, are predefined sets of configurations in which the system is operational (e.g., activated versus idle) and whose functionality is hard-coded (coded not to be changed) into the electrosurgical generator. For example, an RF Done state is a system state that indicates an RF energy cycle has completed without error. User states provide a framework by which customized or specialized operations and values ​​can be established by command from an external source for a particular instrument, procedure, and / or preference.

[0079] In one embodiment, the script describes system states and their exit conditions, such as when to expire or a command to another state, and where a user state begins. For each user state, operating parameters for the specific state, such as power, voltage, and current settings, can be defined or carried over from a previous state. In one embodiment, a user state can provide an instrument, operator, or procedure specific state, and in one embodiment, a user state may be provided for a test or diagnostic specific state.

[0080] 18, when an electrosurgical instrument or device 20 is connected, the generator 10 receives script information from the electrosurgical instrument or device 20. The generator uses this script information to determine the number of states and the order in which the states are to be executed.

[0081] The script source file or script information 180, written by an instrument script author and not resident on the instrument or generator 10, is text or user-readable. The script information is compiled using a script compiler 185 to produce an instrument script database or binary file (SDB) 101. The script binary file is transferred by an instrument key programmer 187 to a memory module connectable to or embeddable in the electrosurgical instrument 20 via an instrument key 182. When an electrosurgical instrument is connected to the electrosurgical generator, the generator authenticates the script binary file and / or the instrument (188). The generator verifies the script binary file (189), and if verified, the action engine utilizes the script (190) to be initiated by an actuation by the connected instrument. The script source file, in one embodiment, is a text file containing an instrument script specific to a particular electrosurgical instrument, generator, and / or surgical procedure. The script source file for the instrument, in one embodiment, contains information containing parameters and scripts (states, functions, events) for the electrosurgical generator and / or electrosurgical instrument. After successful verification, the script compiler assembles the data into a binary format that constitutes the state machine used by the electrosurgical generator. The script compiler, as shown in FIG. 18, in one embodiment, is separate from the electrosurgical generator and is responsible for reading text from the script source file and verifying its contents.

[0082] When the memory module is inserted into the generator, the generator downloads a binary file stored in a ferromagnetic read / write memory (FRAM) or microcontroller located within the module. The binary contains the logic for executing the treatment algorithm. The generator contains firmware / software responsible for processing the binary to authenticate the connected device and then executing the binary to implement the treatment algorithm. As such, the generator is configured to operate only with certified, compatible hand tools.

[0083] In one embodiment, an instrument script or script database represents instrument processes for a particular or given instrument. The instrument script is stored on a memory connected to or integral with the instrument, controller, or combination thereof. An event handler responds to a particular event, such as a switch activation / deactivation, instrument position, or measurement threshold crossing. An action engine based on the detected event, if applicable for a given event, provides an output to the connected instrument. In one embodiment, an event is a discrete change when a switch is asserted or deasserted.

[0084] A script state is a block or a set of script functions or operating conditions and script events or indicators. A script function is a configurable instruction for controlling the generator and / or instrument. A script operator is a logical and comparative operation performed during script event evaluation. A script parameter is configuration data used by all script states and events and, in one embodiment, is declared in their own dedicated section of the script file. A script event is a discrete change in an electrosurgical generator measurement. When a script event occurs, for example, a sequence of script functions is executed.

[0085] According to various embodiments, the phase angle and / or rate of change of the phase angle between the voltage and current is utilized to maximize the length of time the tissue remains within a predetermined temperature range. In one embodiment, the predetermined temperature range is 60°C to 100°C. In one embodiment, a low voltage is utilized to minimize temperature effects while accelerating sealing or melting times.

[0086] According to various embodiments, tissue is grasped between the jaws of a bipolar electrosurgical instrument. The bipolar electrosurgical instrument, removably coupled to an electrosurgical generator, provides RF energy that is delivered to the tissue upon command. The delivered RF energy has a predetermined voltage range that heats the tissue at a predetermined rate. In one embodiment, the predetermined voltage range is 20 Vrms to 50 Vrms. During application of the RF energy, the phase angle between the output voltage and current is monitored to identify an increase or decrease in phase. Initially, the phase angle is monitored to determine the rate of change of the phase angle from an increase to a decrease. It is assumed that once this inflection point occurs, it is determined that the water in the jaws of the instrument has reached 100°C and is above the temperature required to produce the desired tissue effect. A shutoff point is then established to stop the delivery of RF energy.

[0087] An exemplary RF energy control process for an electrosurgical generator and associated electrosurgical tool for melting tissue according to various embodiments is shown in Figures 19-21. In various embodiments, as shown in Figure 19, energy is delivered by the generator through a connected electrosurgical tool (251). The generator monitors at least the phase and / or rate of change of the delivered RF energy (252). If the phase / phase change is greater than zero or positively trending (253), the voltage is increased (254). The generator continues to monitor at least the phase and / or rate of change of the delivered RF energy (255). If the phase and / or phase change continues to increase (256), the generator continues to monitor the phase and / or phase change. If the phase and / or phase change decreases (257), the process is complete or a termination procedure is initiated and / or the RF energy delivered by the generator is stopped (258).

[0088] In one embodiment, prior to the start of the process, impedance is measured to determine a short or open circuit condition via a low voltage measurement signal sent to the connected electrosurgical tool. In one embodiment, passive impedance is measured to determine if the grasped tissue is within the operating range of the electrosurgical tool (2-200 ohms). If the initial impedance check passes, RF energy is delivered to the electrosurgical tool. Thereafter, impedance / resistance is not measured or ignored.

[0089] Initial parameters are initially set to prepare for sealing the tissue placed between the jaws. In one embodiment, voltage and current settings are set for specific settings. In one embodiment, the voltage of RF energy is applied in a ramping manner starting from 30% of the global setting or a user-selected level (e.g., 27.5-88 V for Level 1, 25.0-80 V for Level 2, and 22.5-72 V for Level 3). The voltage DAC is set to 30% of the voltage setting, which is 25.5 Vrms, for Level 2 (medium). The phase is monitored for phase angles above zero degrees, and the tissue and water between the jaws of the electrosurgical instrument are heated at a predetermined slow rate.

[0090] 20 and 21, in various embodiments, a generator delivers energy through a connected electrosurgical tool (251). The generator monitors at least the phase and / or rate of phase change of the delivered RF energy (252). If the phase / phase change is greater than zero or positively trending (253), the voltage is increased (254). In various embodiments, the voltage is increased at a predetermined rate, e.g., 50% over 5 seconds, which is 42.5 Vrms at level 2 (medium) after the phase has increased above zero degrees. Ramping continues until a predetermined condition is met. In one embodiment, ramping continues once the monitored phase angle increases beyond approximately 5°. This ensures that the phase is increasing as expected based on tissue heating.

[0091] In a next state (265), if the monitored phase angle increases beyond a predetermined phase value, e.g., 5°, the phase continues to be monitored for an increasing condition or condition. It is thereby envisioned that such an increasing condition is an indication that the temperature of the tissue and water between the jaws is increasing, but is below 100°C. However, a monitored phase indicating a decreasing condition or condition provides a different indication. It is envisioned that such an indication is that the temperature of the tissue and water between the jaws has reached at least 100°C and / or that the desired tissue effect is complete, e.g., tissue sealing and / or cutting.

[0092] One or more of the following conditions are checked for conditions that increase or decrease the monitored phase angle: According to various embodiments, various small or periodic checks are performed along with various small or periodic updates to various predetermined thresholds or indicators to look for increasing or decreasing phase angle or rate of change conditions.

[0093] An indication is that the desired tissue impact, e.g., tissue sealing and / or cutting, is complete when the phase angle, rate of change, or trend of the phase angle is decreasing rather than increasing, as determined by one or more of the following conditions: It is therefore assumed that the temperature of the tissue and water between the jaws has reached at least 100°C.

[0094] At this or the next condition, the voltage ramping or increase of the output RF energy is decreased or reduced, thus reducing or preventing rapid boiling of the water and maintaining a steady state or constant temperature until a predetermined condition is reached. In one embodiment, the predetermined condition is a decrease in the phase angle by at least 5°.

[0095] According to various embodiments, in a next state (266), if the monitored phase angle increases beyond a predetermined phase value, e.g., 10°, the phase continues to be monitored for an increasing state or condition. However, if the monitored phase angle otherwise indicates a decreasing state, e.g., decreases below a predetermined phase value, e.g., 5° (268), or if a predetermined time limit is reached, the voltage increase is stopped (280). Next, if the monitored phase angle continues to indicate a decreasing state, e.g., decreases below a predetermined phase value, e.g., 5° (268), or if a predetermined time limit is reached, the RF energy is stopped and the process ends (281).

[0096] If the monitored phase angle indicates an increasing state, for example, at the next subsequent state (267), if the monitored phase angle increases beyond a predetermined phase value, for example, 12.5°, the phase continues to be monitored for a continuation of the increasing state or condition. If the monitored phase angle now indicates a decreasing state, for example, if it decreases below a predetermined phase value, for example, 7.5° (269), or if a predetermined time limit is reached, the voltage increase is stopped (280). Next, if the monitored phase angle continues to indicate a decreasing state, for example, if it decreases below a predetermined phase value, for example, 5° (268), or if a predetermined time limit is reached, the RF energy is stopped and the process ends (281).

[0097] In the next post-state (270), if the monitored phase angle indicates an increase condition, e.g., if it increases by more than a predetermined phase value, e.g., 15°, the voltage increase is stopped (271) and the phase continues to be monitored for an increase condition or condition. However, if the monitored phase angle otherwise indicates an increase condition, e.g., if it decreases below a predetermined phase value, e.g., 10° (277), or if a predetermined time limit is reached, the voltage increase is stopped (280). Next, if the monitored phase angle continues to indicate a decrease condition, e.g., if it decreases below a predetermined phase value, e.g., 5° (282), or if a predetermined time limit is reached, the RF energy is stopped and the process ends (281). In the next post-state (272), if the monitored phase angle indicates an increase condition, e.g., if it increases by more than a predetermined phase value, e.g., 20°, the phase continues to be monitored for an increase condition or condition. If the monitored phase angle otherwise indicates a decreasing state, for example, if it decreases below a predetermined phase value, e.g., 10° (277), or if a predetermined time limit is reached, the phase continues to be monitored for a decreasing state or condition. Next, if the monitored phase angle decreases below a predetermined phase value, e.g., 5° (282), or if a predetermined time limit is reached, the RF energy is turned off and the process ends (281).

[0098] In the next post-state (273), if the monitored phase angle continues to indicate an increasing condition, for example, increasing by more than a predetermined phase value, for example, 25°, the phase continues to be monitored for an increasing condition or condition. If the monitored phase angle otherwise decreases below a predetermined phase value, for example, 15° (278), or if a predetermined time limit is reached, the phase continues to be monitored for a decreasing condition or condition. Next, if the monitored phase angle increases below a predetermined phase value, for example, 5° (282), or if a predetermined time limit is reached, the RF energy is stopped and the process ends (281). In the next post-state (274), if the monitored phase angle increases above a predetermined phase value, for example, 30°, the phase continues to be monitored for an increasing condition or condition. If the monitored phase angle otherwise decreases below a predetermined phase value, for example, 15° (278), or if a predetermined time limit is reached, the phase continues to be monitored for a decreasing condition or condition. Next, if the monitored phase angle decreases below a predetermined phase value, for example 5° (285), or if a predetermined time limit is reached, the RF energy is turned off and the process ends (281).

[0099] In the next post-state (275), if the monitored phase angle increases beyond a predetermined phase value, e.g., 35°, the phase continues to be monitored for an increasing condition or condition. However, if the monitored phase angle otherwise decreases below a predetermined phase value, e.g., 15° (278), or if a predetermined time limit is reached, the phase continues to be monitored for a decreasing condition or condition. Next, if the monitored phase angle decreases below 5° (282) or if a predetermined time limit is reached, the RF energy is stopped and the process ends (281). In the next post-state (276), if the monitored phase angle increases beyond a predetermined phase value, e.g., 40°, the phase continues to be monitored for a decreasing condition or condition; if the monitored phase angle decreases below a predetermined phase value, e.g., 15° (278), or if a predetermined time limit is reached, the phase continues to be monitored for a decreasing condition or condition. Next, if the monitored phase angle decreases below a predetermined phase value, e.g., 5° (282), or if a predetermined time limit is reached, the RF energy is stopped and the process ends (281). As envisioned and noted, for the exemplary and operative sealing / melting and cutting / dissecting processes or systems provided above and described throughout this application, the frequency of the tick checks and / or increasing or decreasing conditions, e.g., increasing or decreasing predetermined angles or rate of change instructions, can be varied to provide different and varying levels and granularity of adjustment or control desired or required based on the particular electrosurgical instrument, generator, tissue and / or surgical procedure.

[0100] 22-24 are graphical illustrations of exemplary vessel sealing / melting systems and processes according to various embodiments of the present invention. As shown, the success rate 223 of providing a tissue seal exceeding approximately 3× systolic burst pressure was high, and the time 223 to seal a vessel up to 4 mm in size was short, e.g., less than 2 seconds. The time to seal a vessel from 4 to 7 mm was also short, e.g., less than 5 seconds. The time for the phase angle to decrease from a maximum value to a predetermined phase value, e.g., 5°, was longer than the time to seal up to 4 mm. Such changes or decreases in seal time while providing a successful vessel seal, e.g., withstanding more than 3× systolic burst pressure, according to various embodiments, may be enhanced by identifying and / or triggering at inflection points in the derivative of the phase trend and incorporated into a time check, status indicator, or threshold. In various embodiments, the inflection points in the derivative of the phase trend are identified at the point where the phase trend changes from an increasing state to a decreasing state.

[0101] As shown in FIG. 23, the vessel was 6.62 mm in diameter and successfully sealed, exhibiting, for example, a burst pressure of 12.7 psi. Additionally, as shown, the phase angle 230g increases when RF energy is applied. The rate of increase, as well as the tissue temperature 230d, is not rapid, but rather slow enough. An inflection point 231, e.g., the point at which the phase changes from increasing to decreasing, occurs approximately 1.5 seconds before the RF energy is turned off. As shown in FIG. 24, the vessel was 1.89 mm in diameter and successfully sealed, exhibiting, for example, a burst pressure of 13 psi. The overall trends in the phase angle 240g and temperature 240d are similar to the previous vessel sealing, although the time scale shown in FIG. 24 is approximately one-quarter of the time scale shown in FIG. 23. Also as shown, phases 230g, 240g are shown relative to other tissue readings or indicators, such as voltage 230a, 240a, power 230b, 240b, impedance 230e, 240e, energy 230c, 240c, temperature 230d, 240d, and current 230f, 240f. Additionally, as shown in Figures 23 and 24, in various embodiments, the generator is configured not to measure or calculate one or more of the indicators or readings, such as temperature or energy, to reduce operating and power costs and power consumption and / or generator part count. Additional information or readings are generally provided or shown for related purposes.

[0102] As noted, tissue impedance is near its minimum for the entire sealing cycle. This therefore provides a low voltage and a high current, thus resulting in consistent power delivery throughout the sealing cycle. Effective or consistent power delivery reduces heat spread. According to various embodiments, the time to seal can be reduced, resulting in a reduction in voltage output to less than 50 Vrms and / or a reduction in power output to less than 50 Watts. To avoid erroneous readings, according to various embodiments, the electrosurgical generator does not measure tissue resistance or impedance during delivery of RF energy to the tissue.

[0103] According to various embodiments, an electrosurgical system is provided that allows for low power levels and efficient power delivery, reducing thermal spread to seal vessels or tissue in contact with a bipolar electrosurgical instrument through the controlled and effective delivery of RF energy.

[0104] As described throughout this application, the electrosurgical generator ultimately supplies RF energy to a connected electrosurgical instrument. The electrosurgical generator ensures that the supplied RF energy does not exceed specified parameters and detects fault or error conditions. In various embodiments, the electrosurgical instrument provides the instructions or logic used to properly apply RF energy for a surgical procedure. The electrosurgical instrument includes a memory with instructions and parameters that, in conjunction with the electrosurgical generator, define the operation of the instrument. For example, in a simple case, the generator may supply RF energy, but the connected instrument determines how much energy to apply. However, the generator may not allow the supply of RF energy to exceed a set threshold, even if determined by the connected instrument, thereby providing a check or guarantee against faulty instrument commands.

[0105] Turning now to some of the operational aspects of the electrosurgical tools or instruments described herein in accordance with various embodiments, once a vessel or tissue bundle is identified for fusion, dissection, or both, the first and second jaws are positioned around the tissue. The movable handle 23 is squeezed to move the movable handle proximally relative to the stationary housing 28. As the movable handle moves proximally, the first jaw rotates toward the second jaw, effectively clamping the tissue. Radiofrequency energy is applied to the tissue by pressing an actuation button on the stationary handle. Once the tissue has been fused, dissected, or both, the movable handle is reopened.

[0106] Alternatively or additionally, with the jaws in the fully open position or in an intermediate position between the fully open and engaged positions, radio frequency energy may be applied to tissue in contact with the lower surface or portion of the lower jaw by pressing an activation button or a separate activation button to melt and / or cut the tissue.

[0107] As generally described above and in detail below, various electrosurgical instruments, tools, or devices can be used in the electrosurgical systems described herein. For example, electrosurgical graspers, scissors, tweezers, probes, needles, and other instruments incorporating one, some, or all of the aspects described herein can provide various advantages in electrosurgical systems. Various electrosurgical instrument and generator embodiments, as well as combinations thereof, have been described throughout this application. It is generally contemplated that one, some, or all of the features described throughout this application can be included in any of the instrument, generator, and combination embodiments described below. For example, it may be desirable for each of the described instruments to have memory for interaction with the generators described above, and vice versa. However, in other embodiments, the described instruments and / or generators may be configured to interact with a standard bipolar radio frequency power source without interaction with an instrument memory. Additionally, while various embodiments have been described in terms of modules and / or blocks for ease of explanation, such modules and / or blocks may be embodied by one or more hardware components, such as processors, digital signal processors (DSPs), programmable logic devices (PLDs), application specific integrated circuits (ASICs), circuits, registers, and / or software components, such as programs, subroutines, logic, and / or combinations of hardware and software components. Likewise, such software components may be interchangeable with hardware components or combinations thereof, and vice versa.

[0108] Other embodiments of electrosurgical units, instruments, and connections therebetween, as well as their operation and / or functionality, are described in U.S. patent application Ser. Nos. 12 / 416,668, filed April 1, 2009, entitled "Electrosurgical System," 12 / 416,751, filed April 1, 2009, entitled "Electrosurgical System," 12 / 416,695, filed April 1, 2009, entitled "Electrosurgical System," 12 / 416,765, filed April 1, 2009, entitled "Electrosurgical System," and 12 / 416,128, filed March 31, 2009, all of which are incorporated by reference in their entireties. Certain aspects of these electrosurgical generators, tools, and systems are described herein, and additional details and examples of various embodiments are described in U.S. Provisional Patent Application Nos. 61 / 994,215, filed May 16, 2014, entitled "Electrosurgical Fusion Device," 61 / 944,185, filed May 16, 2014, entitled "Electrosurgical Generator with Synchronous Detector," 61 / 994,415, filed May 16, 2014, entitled "Electrosurgical System," and 61 / 944,192, filed May 16, 2014, each of which is incorporated by reference in its entirety.

[0109] The foregoing description is provided to enable any person skilled in the art to make and use the surgical instruments and practice the methods described herein, and describes the best mode contemplated by the inventors for carrying out the invention. However, various modifications will remain apparent to those skilled in the art. These modifications are intended to fall within the scope of the present invention. In addition, various embodiments or aspects of such embodiments may be seen as illustrated in the various figures and described throughout the specification. It should be noted, however, that although shown or described separately, each embodiment and aspect thereof can be combined with one or more of the other embodiments and aspects thereof, unless otherwise specified. Each combination has not been explicitly set forth merely to enhance the readability of this specification. Moreover, the embodiments of the present invention should be considered in all respects to be illustrative and not limiting.

Claims

1. 1. An electrosurgical system comprising: including electrosurgical instruments, The electrosurgical instrument comprises: a lower jaw including a lower jaw member, a lower conductive pad, a cutting electrode, and an insulator, the insulator electrically insulating the lower conductive pad and the cutting electrode from the lower jaw member, the lower jaw member having a sloped upper outer surface, and the lower conductive pad having a sloped upper outer surface; an upper jaw including an upper jaw member, an upper conductive pad, and an insulating pad, the upper jaw member having a sloped lower outer surface and the upper conductive pad having a sloped lower outer surface; the upper conductive pad and the lower jaw member are configured on one side of a longitudinal axis to melt tissue between the upper and lower jaws using radio frequency (RF) energy, and the upper jaw member and the lower conductive pad are configured on the opposite side of the longitudinal axis to melt tissue between the upper and lower jaws using RF energy; 1. An electrosurgical system, wherein the lower jaw member and the lower conductive pad are configured to cut tissue between the upper and lower jaws using RF energy conducted between the lower jaw member and the lower conductive pad, and the lower jaw member and the cutting electrode are arranged to generate an electrical potential greater than 400 volts such that the RF energy conducted between the cutting electrode and the lower jaw member cuts tissue in contact between the cutting electrode and the lower jaw member, but does not cut tissue between the upper and lower jaws.

2. 2. The electrosurgical system according to claim 1, wherein the upper jaw member further comprises a compressible landing pad having a flat lower surface configured to facilitate electrical division of tissue between the upper jaw and the lower jaw, such that contact and pressure are created between the compressible landing pad and the lower jaw.

3. 3. The electrosurgical system according to claim 2, wherein the compressible landing pad is less stiff than the insulating pad, and the compressible landing pad and the insulating pad are positioned to electrically insulate the upper conductive pad from the upper jaw member.

4. 4. The electrosurgical system according to claim 3, wherein the upper jaw member has a larger cross-sectional shape that is different from the cross-sectional shapes of the upper conductive pad and the compressible landing pad, and the cross-sectional shape of the compressible landing pad is different from the cross-sectional shape of the upper conductive pad.

5. The electrosurgical system according to claim 4 , wherein the lower jaw member has a cross-sectional shape that is different from and larger than the cross-sectional shape of the lower conductive pad.

6. 6. The electrosurgical system of claim 5, wherein a portion of the lower jaw member near a center of the lower jaw and a portion of the lower conductive pad near a center of the lower jaw are both flat and configured to compress the compressible landing pad.

7. 7. The electrosurgical system of claim 6, further comprising an insulated wire extending through a hole in the upper jaw, into a slot in the insulating pad of the upper jaw, to a distal end of the insulating pad of the upper jaw, and to the upper conductive pad of the upper jaw.

8. The electrosurgical system of claim 7 , wherein a central portion of the lower jaw is devoid of electrodes.

9. 8. The electrosurgical system according to claim 7, further comprising an electrosurgical generator removably connected to the electrosurgical instrument, the electrosurgical generator comprising an RF amplifier configured to supply RF energy to the electrosurgical instrument.

10. 10. The electrosurgical system according to claim 9, wherein the electrosurgical generator further comprises a controller configured to monitor a phase angle of RF energy and to signal the RF amplifier to stop delivering RF energy when the monitored phase angle decreases.

11. The electrosurgical system according to claim 10 , wherein the controller is further configured to periodically monitor a rate of change of a phase angle of the RF energy.

12. 12. The electrosurgical system of claim 11, wherein the controller is further configured to send a signal to the RF amplifier to stop delivering the RF energy when the rate of change of the phase angle also falls below a predetermined threshold.

13. 11. The electrosurgical system according to claim 10, wherein the RF amplifier is configured to supply RF energy to maintain a temperature between the upper and lower jaws below 100°C while increasing the voltage of the RF energy.

14. 14. The electrosurgical system of claim 10 or 13, wherein the electrosurgical generator further comprises a power supply configured to supply a DC voltage to the RF amplifier, the RF amplifier configured to convert the DC voltage from the power supply into a sinusoidal waveform and supply the sinusoidal waveform as the RF energy to the electrosurgical instrument.

15. 15. The electrosurgical system of claim 14, wherein the RF energy is supplied between the upper conductive pad and the lower jaw member and between the upper jaw member and the lower conductive pad to heat tissue between the upper and lower jaws to a temperature of between 60°C and 100°C and denature collagen present in the tissue between the upper and lower jaws.

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