Patent Description:
Electrosurgical devices or instruments have become available that use radiofrequency (RF) energy to perform certain surgical tasks such as coagulate, fuse, or cut tissue. Such electrosurgical instruments typically fall within two classifications: monopolar and bipolar. In monopolar instruments, electrical energy is supplied to one or more electrodes on the instrument with high current density while a separate return electrode is electrically coupled to a patient and is often designed to minimize current density. Bipolar electrosurgical instruments, which operate without separate return electrodes, can deliver electrical signals to a focused tissue area with reduced risks.

Even with the relatively focused surgical effects of bipolar electrosurgical instruments, surgical outcomes are often highly dependent on surgeon skill. Enhanced generators have been made to reduce this dependency. However, such generators have had shortcomings in that they can provide inconsistent results in determining tissue coagulation, fusion, or cutting endpoints for varied tissue types or combined tissue masses. These systems can also fail to provide consistent electrosurgical results among use of different instruments; having different instrument and electrode geometries and subjected to different tissue types and tissue amounts. Some of these shortcomings are sometimes exacerbated by inaccurate RF energy generation, measurement, calibration and testing of such systems. Unavailable or unreliable test equipment and/or unavailable or inexperienced personnel also contribute to these shortcomings or do little to assist in overcoming these shortcomings. Hence, embodiments of the present invention are intended to obviate or at least alleviate the aforementioned problems of the conventional electrosurgical generators.

A known example of an electrosurgical system which performs self-verification is disclosed in <CIT>.

In accordance with the present invention there is provided an electrosurgical system as recited in claim <NUM> for sealing, fusing and/or cutting tissue.

Many of the attendant features of the present inventions will be more readily appreciated as the same becomes better understood by reference to the foregoing and following description and considered in connection with the accompanying drawings.

In the appended figures, similar components and/or features may have the same reference label. Where the reference label is used in the specification, the description is applicable to any one of the similar components having the same reference label.

This disclosure relates in general to electrosurgical systems. It specifically relates to a new generation of electrosurgical generators capable of initiating and performing an auto-verification and self-verification system test of the generators.

To maintain an electrosurgical generator, verification of the generator's output is often required to ensure the RF being outputted from the generator is as intended. This verification can be performed periodically, e.g., every twelve months or two years and often by a user interactive or manual system or process. The system or process may also require the connection of various external devices to the generator. These external devices may include a verification adapter, external loads, e.g., <NUM>-<NUM> Ohm loads with decreasing power ratings and increasing voltage ratings, and/or measuring devices, e.g., oscilloscope, differential voltage probe and current probe.

The user must then connect the appropriate adapter, loads and/or measuring devices and perform specified tests requiring adjustments to the generator, external devices and/or measuring devices and connections thereto. Additionally, appropriate monitoring and recording the test results are required along with understanding errors and physically removing a faulty generator from use. Also, to perform the generator's output verification, the generator must be taken out of circulation and not be used in a surgical procedure, and often times not performed at a surgical site such as, for example, hospitals, due to lack of experience, personnel or equipment.

Embodiments of the present invention are directed to systems for enhancing surgical outcomes by providing generators having accurate RF energy generation, measurement, calibration and/or selftesting system. The present invention allows detection of failure, thereby reducing troubleshooting and surgical operational time while avoiding other potential surgical difficulties. This is achieved through implementation of an automated self-verification process after a predetermined amount of time after power start-up of the electrosurgical generator.

The electrosurgical generators of electrosurgical systems in accordance with various embodiments include a plurality of switchable impedance loads for performing the self-verification process. The internal impedance load with multiple configurations are utilized to verify the voltage, current, power, and/or phase measurements of the generator. By incorporating or integrating the self-verification process and its related hardware resources within the electrosurgical generator, many improvements in outcome of pre-surgical procedures may be achieved. By way of examples, these improvements may include, but not limited to, elimination for connecting external devices to the generator, thereby removing the risk of using unavailable or unreliable test equipment, and/or unavailable or inexperienced personnel. In addition, the need for taking the generator out of circulation for performing the generator's output verification is completely eliminated.

In the following, the electrosurgical system according to various embodiments of the present invention is explained in detail with sections individually describing: the electrosurgical generator, the electrosurgical instrument and the control system and method used for performing the automated self-verification system test of the generator.

In accordance with various embodiments, an electrosurgical system is provided having an electrosurgical generator that controls the delivery of electrosurgical or radiofrequency (RF) energy, adjusts the RF energy and in various embodiments measures and monitors electrical properties, e.g., phase, current, voltage and/or power, of the supplied RF energy to a connectable electrosurgical instrument to ensure optimal sealing, fusing and/or cutting of tissues or vessels. In various embodiments, the generator may include a feedback system that determines such electrical properties and through a microcontroller regulates and/or controls an RF amplifier that generates the required RF energy to provide the optimal RF output for sealing, fusing and/or cutting tissue/vessels under dynamic conditions, such as for example, varying loads, procedural or operational conditions.

Referring first to <FIG>, an exemplary embodiment of an electrosurgical system according to various embodiments of the present invention is illustrated. As shown in these figures, the electrosurgical system may include an electrosurgical generator <NUM> and a removably connectable electrosurgical tool or instrument <NUM>. The electrosurgical hand device or instrument <NUM> can be electrically coupled to the generator <NUM> via a cabled connection with a device key or connector <NUM> extending from the instrument <NUM> to a device connector or access port <NUM> on the generator <NUM>. The electrosurgical instrument <NUM> may include audio, tactile and/or visual indicators to apprise a user of a particular or predetermined status of the instrument <NUM> such as, for example, a start and/or end of a fusion operation. In some embodiments, a manual controller such as a hand or foot switch can be connectable to the generator <NUM> and/or instrument <NUM> to allow predetermined selective control of the instrument such as to commence a fusion operation.

In accordance with various embodiments, the electrosurgical generator <NUM> includes a display <NUM> that may indicate the status of the electrosurgical system including, among other information, the status of the one or more electrosurgical instruments and/or accessories, connectors or connections thereto, the state or operations of the generator and error indicators. The electrosurgical generator <NUM> in accordance with various embodiments of the present invention may include a user interface such as, for example, a plurality of buttons <NUM>. The plurality of buttons <NUM> allows for user interaction with the electrosurgical generator <NUM>. This user interaction may include, for example, requesting an increase or decrease in the electrical energy supplied to one or more instruments <NUM> that are coupled to the electrosurgical generator <NUM>. In various embodiments, the generator <NUM> further includes a user-accessible power-on switch or button <NUM> that when activated powers the generator <NUM> and activates or initiates a self-verification system test of the generator. In other embodiments, the display <NUM> can be a touch screen display thus integrating data display and user interface functionalities.

In various embodiments, the electrosurgical generator <NUM> of the present invention is configured to output radiofrequency (RF) energy through the connectable electrosurgical instrument or hand device <NUM> to seal, fuse and/or cut tissue or vessels via one or more electrodes. The electrosurgical generator <NUM>, according to the embodiments of the present invention, is configured to generate up to 300V, 8A, and 375VA of RF energy and it is also configured to determine a phase angle or difference between RF output voltage and RF output current of the generator during activation or supply of RF energy. In this way, the electrosurgical generator <NUM> regulates voltage, current and/or power and monitors RF energy output (e.g., voltage, current, power and/or phase). In one embodiment, the generator <NUM> may stop, terminate or otherwise disrupt RF energy output under predetermined conditions. By way of example, these predetermined conditions may be any of the following conditions: when a device switch is deasserted (e.g., fuse button released), a time value is met, and/or active phase angle and/or change of phase is greater than or equal to a phase and/or change of phase stop value indicating end of an operation such as fusion or cutting of tissue.

The electrosurgical instrument <NUM>, according to the embodiments of the present invention, may include an elongate shaft <NUM> having a proximal end coupled to or from which an actuator <NUM> extends and a distal end coupled to or from which jaws <NUM> extend. A longitudinal axis extending from the proximal end to the distal end of the elongate shaft <NUM>. In one embodiment, the actuator <NUM> may include a movable handle <NUM> which is pivotably coupled to a stationary handle or housing <NUM>. The movable handle <NUM> is coupled to the stationary handle or housing <NUM> through a central or main floating pivot. In operation, the movable handle <NUM> is manipulated by a user, e.g., a surgeon, to actuate the jaws <NUM> at the distal end of the elongate shaft <NUM>, and thereby, selectively opening and closing the jaws <NUM>. When tissue or vessels are grasped between the jaws <NUM>, a switch or button <NUM> is activated by the surgeon to seal, fuse and/or cut the tissue/vessels between the jaws <NUM>. Once the button <NUM> is activated, associated circuitry or contacts are connected to connect appropriate electrodes of the jaws with associated connections of the generator <NUM> to supply RF energy to tissue grasped between the jaws <NUM> or otherwise in contact with the one or more electrodes of the jaws.

In various embodiments, the electrosurgical instrument <NUM> further includes a mechanical or electrical cutting blade that can be coupled to a blade actuator such as a blade lever or trigger <NUM> of the stationary handle or housing <NUM>. The cutting blade is actuated by the blade trigger <NUM> to divide or cut the tissue between the jaws <NUM>. In various embodiments, a blade slider is connected to the blade trigger <NUM> and a protrusion extends from a proximal portion of the blade slider into an opening in one end of the blade trigger connecting the components together. The other end of the blade trigger is exposed and accessible by the user with the blade trigger <NUM> being pivotable about a trigger pivot at or near the midpoint of the blade trigger. As such, as the blade trigger <NUM> is pulled or rotated by the user proximally, the end of the blade trigger connected to the blade slider slides or moves the blade slider distally. Integrated with or attached to a distal end of the blade slider is a cutting blade, knife or cutting edge or surface. As such, as the blade slider translates longitudinally through a blade channel in the jaws, tissue grasped between the jaws <NUM> is cut. In one embodiment, the cutting edge or surface is angled to facilitate cutting of the tissue between the jaws <NUM>. In various embodiments, the cutting blade is a curved blade, a hook, a knife, or other cutting element that is sized and configured to cut tissue between the jaws <NUM>.

In accordance with various embodiments, the elongate shaft <NUM> comprises an actuation tube or rod coupling the jaws <NUM> with the actuator. In one embodiment, the actuator includes a rotation shaft assembly including a rotation knob <NUM> which is disposed on an outer cover tube of the elongate shaft <NUM>. The rotation knob <NUM> allows a surgeon to rotate the shaft of the device while gripping the actuator. In various embodiments, the elongate shaft <NUM> is rotatable <NUM> degrees and in other embodiments, rotation of the elongate shaft <NUM> is limited to <NUM> degrees, i.e., ninety degrees clockwise and ninety degrees counter clockwise. <FIG> illustrates an alternative embodiment of an electrosurgical hand device <NUM>' connectable to the electrosurgical generator <NUM>. The electrosurgical hand device <NUM>' is similar but includes different features and has a different surgical use than the electrosurgical hand device <NUM>.

Referring next to <FIG>, a block diagram of an electrosurgical generator <NUM> according to the embodiments of the present invention is shown. As shown in this figure, the electrosurgical generator <NUM> may include a power entry module <NUM>, e.g., an AC main input, coupled to a power supply module, e.g., two 48V DC power supplies <NUM>, <NUM>. The power supply module converts the AC voltage from the AC main input to a DC voltage and via a house keeping power supply <NUM> provides power to various circuitry of the generator <NUM> and in particular supplies power to an RF amplifier <NUM> that generates or outputs the RF energy. In one embodiment, the RF amplifier <NUM> may include a combined Buck and H-Bridge circuitry to convert a DC voltage input into an RF output and in another embodiment into a variable amplitude <NUM> sine wave. The DC voltage input is a 96V DC input that is generated by the two 48V DC power supplies <NUM>, <NUM> coupled in series. One of the 48V DC power supply <NUM>, <NUM> is configured to generate low voltage rails and in particular supply standby voltage to power on the generator <NUM>.

The RF output and in various embodiments the amplitude of the RF waveform output is controlled and regulated by an electrosurgical control system or a digital integral servo control system <NUM> embedded or integrated within the electrosurgical generator <NUM>. <FIG> illustrates, in greater detail, a block diagram of an embodiment of a control system <NUM> of the electrosurgical generator <NUM> coupled to an electrosurgical hand device <NUM>. As shown in <FIG>, the control system <NUM> may include the RF Amplifier <NUM>, a primary microcontroller <NUM> and a feedback system <NUM>. The control system <NUM> varies between regulating voltage, current, or power of the RF output generated by the RF Amplifier <NUM>. In various embodiments, the feedback system <NUM> measures the RF output and, after processing the measured data, digitally feeds the RF output's real and imaginary components to the primary microcontroller <NUM>. The primary microcontroller <NUM>, according to the embodiments of the present invention, may include a primary field programmable gate array (FPGA) and a processor. By way of example, the processor of the microcontroller <NUM> may include an advanced reduced instruction set machine (ARM) processor. The primary FPGA processes the received data from the feedback system <NUM> and adjusts the output of the RF amplifier <NUM> to meet a desired regulation target. In various embodiments, the feedback system <NUM> comprises of analog input, digital processing and digital output.

With reference to <FIG>, a block diagram of an embodiment of the feedback system <NUM> within the control system <NUM> of the electrosurgical generator <NUM> is shown in greater detail. As shown in this figure and in accordance with various embodiments of the present invention, the verification system <NUM> may include a main channel <NUM> and a redundant channel <NUM>. The main channel <NUM> and redundant channel <NUM> in various embodiments may include separate but identical components. Additionally, the main and redundant channels <NUM> and <NUM> follow separate but identical electrical paths and in one embodiment are both connected to the RF amplifier <NUM> and the RF output.

The feedback system <NUM> further includes a verification channel <NUM> which in various embodiments is separate but similar to the main channel <NUM> and redundant channel <NUM>. The verification channel <NUM> may include components that are separate from the other channels but are similar. In one embodiment, the verification channel <NUM> may include the same components as the main and redundant channels <NUM> and <NUM>, but the components in the verification channel <NUM> have higher ratings, e.g., higher resolution and/or lower drift, and are often more costly. In another embodiment, the verification channel <NUM> may include the same components as the main and redundant channels <NUM> and <NUM>. However, in various embodiments, the verification channel <NUM> is only used in the operation of or by the self-verification test system. As such, the components of the verification channel <NUM> are used less often and thus may remain more accurate, e.g., have less drift, than the components of the main and/or redundant channels <NUM> and <NUM> that are constantly used throughout the generator's operations. In various embodiments, the verification channel <NUM> follows a separate but identical electrical path as the main and redundant channels <NUM> and <NUM> and in one embodiment is connected to the RF amplifier <NUM> and the RF output.

The channels <NUM>, <NUM> and/or <NUM> in accordance with various embodiments comprises circuitry including active and/or passive components and electrical pathways connected thereto arranged to transmit and/or measure the RF energy supplied from the RF amplifier to the microcontroller and/or as directed by the microcontroller. In accordance with various embodiments, one or more or all the channels includes and/or are connected to one or more measurement circuitry comprising sensors, detectors, comparators, resistors, memory and/or the like and/or any combination thereof configured to measure, calculate and/or record such measurements of electrical properties (e.g., current, voltage, power, and/or phase) of the RF energy directed across the one or more or all the channels.

In accordance with various embodiments of the present invention, the electrosurgical generator <NUM> is further configured to provide RF output in three resolution settings: low voltage, normal or medium voltage and high voltage ranges. In various embodiments, device scripts stored and located on connectable electrosurgical hand devices, e.g., instrument <NUM>, and/or connectors coupled thereto, e.g., device key <NUM>, are used to determine or set the RF output or voltage mode.

In various embodiments, the electrosurgical generator <NUM> logs all RF output data onto an internal memory device, e.g., a secure digital (SD) or non-volatile memory card. The memory device is configured to be read through an interface port <NUM>, e.g., a universal serial bus (USB) port, on the electrosurgical generator <NUM> (best shown in <FIG>). In various embodiments, the generator <NUM> is configured to copy the data from the internal memory device to a connectable portable storage device, e.g., a USB flash drive, through the interface port of the generator.

Reffering back to <FIG> & <FIG> and in accordance with various embodiments, the electrosurgical generator <NUM> is configured to alert the surgeon when the vessel has reached a completed procedure state, e.g., a completed seal state, or if an error or fault condition has occurred. The electrosurgical generator <NUM> in various embodiments may include visual, tactile and/or audible outputs to provide such alerts or other indicators or information to the surgeon as dictated by the surgical procedure, device script or health or operational information regarding the device <NUM> and/or generator <NUM>. In one embodiment, the generator <NUM> via a front panel interface <NUM> alerts the surgeon through the LCD display <NUM>, which is integrated into a front panel of the generator, and in various embodiments provides specific audible alarm or informational tones through a speaker <NUM> also integrated into the front panel of the generator. The generator <NUM> in various embodiments may include a front panel overlay <NUM> that provides a user interface or access including navigational push buttons to allow user access to systems settings such as volume or display brightness. The front panel overlay <NUM> may also include the system power button or connection. In various embodiments, a fan system <NUM> is provided to assist in heat dissipation. Additionally, as illustrated in the <FIG>, signal or sig represents connections that, for example, comprise of digital signals used to communicate information across systems and/or printed circuit boards, power represents connections that, for example, comprise of voltage rails used to power systems and/or printed circuit boards and RF represents connections that, for example, comprise of high voltage, high current RF energy used to seal, fuse or cut tissue or vessels.

As described further above, the electrosurgical generator <NUM> in various embodiments further includes the user-accessible power-on switch or button <NUM> that is accessible by a surgeon to activate or turn on the generator <NUM>. In one embodiment, the power-on switch <NUM> is on a front panel of the generator. In accordance with various embodiments, once the generator <NUM> is activated by the activation of the power-on switch <NUM>, the generator <NUM> initiates or activates a power on self-verification system test. During the self-verification system test, in various embodiments, the generator <NUM> verifies regulation of the RF output in one or more RF modes and/or one or more RF resolution settings. In accordance with various embodiments, the RF regulation modes include voltage, current and power regulation modes and the RF resolution settings include low, normal and high voltage settings.

With reference to <FIG>, a schematic illustration of an example of hardware resources implemented within an electrosurgical generator <NUM> to perform self-verification system test is shown. As it can be seen from this figure, one or more impedance load <NUM> may be implemented within the RF amplifier <NUM> of the control system <NUM>. In various embodiments, the control system <NUM> from the electrosurgical generator <NUM> may include one or more impedance loads <NUM> which are internal and/or integrated within the generator <NUM>. It should be understood that the impedance loads <NUM> are not user-accessible and in various embodiments they are only used for the purpose of performing the self-verification system test of the generator <NUM>. The one or more impedance loads <NUM>, according to the embodiments of the present invention, may be resistive, capacitive, inductive, and any combination thereof. The self- verification system test process utilizes the impedance loads <NUM> to verify the voltage, current, power, and/or phase measurements of the generator <NUM>.

In some embodiments, the impedance loads <NUM> are attached or integrated into the RF amplifier <NUM>. In other embodiments, various configuration of the impedance loads <NUM> may be selected via one or more relays or switches <NUM>. In one embodiment, the impedance loads <NUM> are in a parallel configuration. In another embodiment, the impedance loads <NUM> are in series, parallel or a combination thereof to provide different load configuration or values for other self-verification settings or testing.

The impedance loads <NUM>, according to the embodiments of the present invention, are internal to avoid potential inaccuracies or errors due to the use of external impedance loads, such as connections, e.g., variable losses due to cabling, load properties, e.g., phase changes, user error, and equipment tolerances or errors thereto. The internal or integrated self-verification system including but not limited to the internal impedance loads <NUM> also avoids the need for additional measurement equipment, e.g., oscilloscopes, or specialized equipment, e.g., test electrosurgical instruments or keys, or accessories, e.g., adapters, along with any potential inaccuracies associated with the use of such equipment. Also, any setup time or scheduling of time to perform such verification is also avoided through the automatically scheduled and executed self-verification system test.

Table I summarizes exemplary self-verification processes performed in various RF regulation modes and RF resolution settings. In accordance with various embodiments, each process step may have specific regulation values and impedance loads configuration. After setting the regulation values and activating the verification relays <NUM>, the RF amplifier <NUM> generates the RF output and supplies the RF output to the internal impedance loads <NUM> implemented within the RF amplifier <NUM> as directed by the self-verification system test. Accordingly, the control system <NUM> regulates the RF output to the set value and the feedback system <NUM> measures various electrical characteristics of RF output from the main channel <NUM>, redundant channel <NUM> and verification channel <NUM> and feeds digitally the measured results to the microcontroller <NUM> for further processing. The primary microcontroller <NUM> compares the measured data or readings of the main and redundant channels <NUM> and <NUM> to the verification channel <NUM> and accordingly initiates or halts the supply of RF energy.

In accordance with various embodiments, in order for the self-verification tests to pass, the measurements of all the feedback system channels <NUM>, <NUM> and <NUM> must match each other and/or be within a certain tolerance and/or match a target RF set point. More specifically, the main channel <NUM>, redundant channel <NUM>, and verification channel <NUM> have to be within a certain tolerance of a nominal value based on the internal load impedance configuration and target RF set point to prevent false positives if all readings of three channels are identical but offset. For example, if all the feedback system channels <NUM>, <NUM> and <NUM> read or measure <NUM> volts from the RF output on a <NUM> volt test, the test will fail or not pass even though the channels identified identical voltage measurements.

In accordance with various embodiments, at the factory level after an electrosurgical generator <NUM> passes top level calibration and verification in the production process, initial verification channel offsets are calculated. The initial offset values are calculated by comparing the main and redundant channel readings to that of verification channel and offsetting them to the verification values. As a result, this sets the main, redundant, and verification channel readings to identical values. The primary microcontroller <NUM>, in various embodiments, utilizing the ARM processor, applies these initial offsets internally for each verification test or process. Therefore, for example, if the internal impedance loads, e.g., shunt resistors, on any of the main, redundant and verification channels <NUM>, <NUM> and <NUM> start to drift after the initial offset adjustment the self-verification system test of the generator <NUM> will identify the drift and/or otherwise indicate an error or failure.

A self-verification system test failure, according to the embodiments of the present invention, will display on the generator's LCD <NUM> and/or the generator <NUM> will not function such that no RF energy will be supplied to a connected electrosurgical instrument <NUM>. In various embodiments, the generator's power can be cycled off and on and the self-verification system test will initiate again and, in various embodiments, after a predetermined number of failures in a particular sequence, e.g., two verification failures in a row, the electrosurgical generator <NUM> will fault or enter into a nonfunctional state and will require service before being able to operate, e.g., be able to supply RF energy to a connected electrosurgical instrument <NUM>.

With the self-verification system operating at the generator or system power-on or startup, the electrosurgical generator <NUM> is configured to notify the surgeon of a potential generator issue, prior to any use of a connected electrosurgical instrument <NUM> or any supply of RF energy to the tissue or vessel through the electrosurgical instrument <NUM>.

As such, without the self-verification system during the generator's startup or power-on operation, a conventional generator would not detect an RF output failure until a surgeon attempted to apply RF energy to tissue, if at all. The electrosurgical generator <NUM> according to the embodiments of the present invention is thus configured to detect failures on startup or a predetermined schedule which reduces troubleshooting and surgical operational time and avoids other potential surgical difficulties.

In various embodiments, the verification channel <NUM> has components of lower drift and higher resolution (higher quality and lower PPM/°C). As such, the low thermal coefficients, which can dictate the drifts of the components, ensures that the verification channel <NUM> is more resistant to change over time and temperature. Additionally, components, such as shunt resistors, of the verification system channels <NUM>, <NUM> and <NUM> may drift in value over time due to heat generated by the RF output. This drift can skew measurement values. However, since the components, e.g., the impedance loads, of the verification channel <NUM> are not utilized during normal RF output operations, the verification channel <NUM> is more resistant to drift.

As described further above, the verification channel <NUM> uses the normal RF output path, which is then redirected using relays <NUM> to self-verification resistors and capacitors, e.g., impedance loads <NUM>, inside the electrosurgical generator <NUM> instead of the normal RF output path to a connected electrosurgical hand device <NUM>. In various embodiments, high power loads, e.g., resistors, inductors or capacitors, are used to withstand or resist adverse effects, such as temperature, introduced through the application of RF energy. In one embodiment, high power resistors are provided and in other embodiments there are chassis mounted and placed in the airflow path of the generator to enhance heat dissipation.

In some embodiments, the impedance loads of the verification channel <NUM> are included or integrated on the same circuit board as the other channels <NUM> and <NUM> of the feedback system <NUM> that reduces the overall footprint of the electrosurgical generator <NUM> or the feedback system <NUM>. In other embodiments, the impedance loads of the verification channel <NUM> are included or integrated on the different circuit board thereby reducing any affect to surrounding components due to heat generated by the impedance loads. In various embodiments, the impedance loads are varied, e.g., different value components, e.g., resistors, or different components, e.g., inductors used instead of capacitors for phase measurements, to enhance additional variations in the regulation modes being verified. In addition, the impedance loads may be in series, parallel or any combination thereof to provide various load configuration or values.

In some embodiments, the verification channel measurement circuit is positioned in series with the RF output circuit enhancing accuracy of the measurements and easing tracking or recording of such measurements. In other embodiments, the verification channel measurement circuit is separated, e.g., via a relay, from the RF output circuit and thus can enhance the resistant of the verification channel measurement circuit due to reduced operation time or the effects of heat due to supply of RF energy.

Referring next to <FIG>, an embodiment of a self-verification system operations or processes according to the embodiments of the invention is shown. The depicted portion of the process <NUM> begins in step <NUM> where the algorithm powers on the electrosurgical generator <NUM> as a starting point. After starting-up the generator <NUM>, a determination is made, at step <NUM>, as to whether the previous self-verification system test has failed. If failure of the previous self-verification system test is detected, processing flows from block <NUM> to block <NUM> where the processing waits for a predetermined period of time (cooldown period) or power-on threshold, e.g., one minute, prior to initiating the self-verification system test at block <NUM>. If failure of the previous self-verification system test is not detected, processing goes from block <NUM> to block <NUM> where another determination is made as to whether the predetermined period of time or power-on threshold has elapsed after the electrosurgical generator <NUM> is started.

If the power-on threshold is reached or exceeded, processing flows from block <NUM> to block <NUM> to initiate the self-verification system test. If the power-on threshold is not reached in block <NUM>, processing goes to block <NUM> to wait for the predetrmined period of time (cooldown period) or power-on threshold to pass. The processing then goes to block <NUM> for initiating the self-verification system test.

Once the self-verification system test is initiated at block <NUM>, the electrosurgical generator <NUM> is verified using various processing tests. After completion of the self-verification system test, processing continues to block <NUM> where a determination is made as to whether a failure of the electrosurgical generator <NUM> has been detected during the self-verification process. If a failure is not detected, processing flows from block <NUM> to block <NUM> where the electrosurgical generator <NUM> is configured to supply RF energy to a connected electrosurgical hand device <NUM>. In this embodiment, the electrosurgical generator <NUM> may provide a display or other indication that an electrosurgical device <NUM> can be connected to the generator <NUM> or the device already connected to the generator <NUM> is ready for surgical use. In other embodiments, device authentication and/or verification is also performed by the electrosurgical generator <NUM>, prior to and/or after the generator <NUM> is verified by the self-verification system, before the connected electrosurgical instrument <NUM> is ready for surgical use. In accordance with various embodiments of the present invention, the processing determines that the electrosurgical generator <NUM> has no failure if one or more or all of the verification processes or tests are passed successfully.

If a failure of the electrosurgical generator <NUM> is detected, processing goes from block <NUM> to block <NUM> where another determination is made as to whether a failure threshold has been reached. The failure threshold determines if the self-verification system has failed consecutively a predetermined number of times, e.g., twice or more in a row. If the failure threshold is reached, processing flows from block <NUM> to block <NUM> where an error is generated causing the generator <NUM> to be inoperable. In this embodiment, the inoperative state of the generator <NUM> requires that the electrosurgical generator <NUM> to be serviced. In accordance with various embodiments of the present invention, the electrosurgical generator <NUM> notifies the user or surgeon, of the generator's error via an audible, tactile and/or visual indicator.

If the failure threshold is not reached in block <NUM>, the processing then goes back to block <NUM> for restarting the electrosurgical generator <NUM> in which the processing can again attempt to verify the generator <NUM>. This process continues until a failure of the electrosurgical generator <NUM> is not detected or the failure threshold is reached or exceeded.

With reference to <FIG>, a flow diagram of an embodiment of process <NUM> for performing self-verification system test is shown. Self-verification process steps for various RF regulation modes and RF resolution settings are typically recorded or stored into a memory of the electrosurgical generator <NUM> of the present invention. In accordance with various embodiments, each process step may have specific regulation values and impedance loads configuration. Exemplary self-verification processes were provided further above in Table I. After initiating the self-verification system test, the depicted portion of the process begins in blocks <NUM> where the algorithm sets the RF regulation modes and RF resolution settings. As such, the processing sets the voltage mode, activates appropriate relays <NUM> for obtaining specific load configuration and sets the regulation value. The processing then goes to block <NUM> for generating RF output and providing RF energy to the verification system loads. In various embodiments, the RF amplifier <NUM> generates the RF output and supplies the RF output to internal loads <NUM> within the amplifier as directed by the self-verification system.

Once the RF output is generated, processing flows to block <NUM> where the feedback system <NUM> measures the electrical characteristics of the RF output. The control system <NUM>, in accordance with various embodiments of the present invention, regulates the RF output to the set value as directed by the self-verification system and the feedback system <NUM> measures voltage, current, power, and/or phase from the main, redundant and verification channels <NUM>, <NUM>, and <NUM>. After measuring the electrical characteristics of the RF output, processing flows to block <NUM> where the primary microcontroller <NUM> performs calculations, comparison and analysis of the measured data. In various embodiments, the feedback system <NUM> communicates the measured data and/or real and imaginary components thereof for the channels <NUM>, <NUM>, and <NUM> to the primary microcontroller <NUM> for further processing. The primary microcontroller <NUM> in various embodiments compares the data or readings of the main and redundant channels <NUM> and <NUM> to the verification channel <NUM> and if the main and redundant readings are less than a predefined tolerance or difference, e.g., <NUM>%, the self-verification process step or test is passed or verified. Otherwise, the verification process step or test fails. In accordance with various embodiments of the present invention in both cases the results are recorded or stored into a memory of the electrosurgical generator <NUM> and/or the device key <NUM> of the electrosurgical instrument <NUM>.

A determination is made at block <NUM> as to whether the self-verification system test of the electrosurgical generator <NUM> has been completed. If the self-verification system test is completed, the processing flows from block <NUM> to block <NUM> where a timestamp for recording test completion is generated before exiting the self-verification process. If the self-verification system test is not completed, the processing then goes back to block <NUM> for setting the new RF regulation mode and new RF resolution setting. This process continues until all of the self-verification process steps for verifying the electrosurgical generator <NUM> are performed. In various embodiments, the self-verification system test activates at a predetermined condition, such as on power-on, device connection and/or script or device activation, and/or along a predetermined schedule, e.g., at each predetermined conditions and/or a selected interval. In various embodiments, a separate button, switch or the like is provided on the generator, a connectable device and/or adapter utilized to activate the self-verification test.

The electrosurgical generator <NUM>, according to the embodiments of the present invention, is configured to operate in one or more specific voltage modes. In various embodiments, the voltage modes are low, medium and high and in various embodiments the voltage mode adjusts or effects the feedback system <NUM>. Voltage mode, in various embodiments, determines gain settings on the ADCs (Digital to Analog Convertors) used in the feedback system <NUM> and in various embodiments, high voltage is a maximum 300V gain settings, medium voltage is a maximum 150V gain settings, and low voltage is a maximum 10V gain settings. By having different gain settings for the different voltage modes, the resolution of the measurement of the feedback system <NUM> is increased.

According to the embodiments of the present invention, the RF amplifier may include an autotransformer directly connected to a primary transformer of the RF amplifer to supply high voltage mode. In various embodiments, when the RF amplifier <NUM> is operating in the high voltage mode (autotransformer on), the RF output may reach up to 300V and 4A. On the other hand, when the autotransformer is off, the RF amplifier <NUM> may operate in the normal voltage mode, RF output limited to 150V and 8A, and in the low voltage mode or passive mode which is limited to 10V and 100mA.

In some embodiments, the self-verification system test varies the voltage modes to test or ensure the different gain settings are accurate across the main, redundant and verification channels <NUM>, <NUM>, and <NUM> of the feedback system <NUM>. In other embodiments, different regulation modes of voltage, current and power are also included with the various voltage modes which are utilized and tested in the self-verification system test.

In accordance with various embodiments of the present invention, the measurements and calculations provided by the main and redundant channel <NUM> and <NUM> are compared to the measurements and calculations of the verification channel <NUM>. If the channels <NUM>, <NUM>, and <NUM> all match and in various embodiments within a set tolerance, then the self-verification system test according to the embodiments of the present invention clears or allows the electrosurgical generator <NUM> to continue and thus allow RF output to a connected electrosurgical device <NUM>. The main, redundant and verification channels <NUM>, <NUM>, and <NUM> in various embodiments must also be within a set tolerance compared to a nominal regulation value to also allow the verification system to clear the generator for operation.

According to the embodiments of the present invention, the low voltage mode is only used for passive measurement and does not set a constant voltage, current, or power. In various embodiments, it also does not utilize the verification channel <NUM> and thus RF output is provided in low voltage. In this embodiment, voltage and current are measured, the resistance is calculated and some or all of the measurements and calculations are compared to predefined values and/or within a predefined tolerance to further clear or allow the electrosurgical generator <NUM> for further operations.

In various embodiments, the self-verification system determines or checks the drift of the sense devices such as, for example, resistors, capacitors or inductors of the main and redundant channels <NUM> and <NUM> which are used to measure or calculate electrical properties of the RF output. If the drift of these components is minimal or within a predefined range and/or the unit can regulate to set values appropriately, then the RF output of the electrosurgical generator <NUM> is determined to have no failure by the self-verification system test and the self-verification process allows the generator <NUM> for further operational or surgical use.

<FIG> illustrates a flow diagram of an example method for performing a self-verification system test of an electrosurgical generator <NUM>. This process or system test verifies that the electrosurgical generator <NUM> can output RF energy at a set value, and that the feedback system <NUM> is accurately measuring this RF output across all channels <NUM>, <NUM> and <NUM>. In accordance with various embodiments of the present invention, RF output is first generated and thus provided to the self-verification system. In various embodiments, when the generator is powered on, e.g., the power button <NUM> on the front panel of the generator <NUM> is pressed, the generator <NUM> initiates the self-verification system process. This will cause the RF output to be supplied or be directed to an internal load rather than through a connected electrosurgical device <NUM>. As shown in <FIG>, the self-verification process bypasses or switches off relays <NUM> and <NUM> that would direct the RF output or the electrosurgical energy to a connected electrosurgical device, e.g., fusion device <NUM>. It should be understood that an electrosurgical device does not need to be connected to the electrosurgical generator <NUM> for the self-verification system to operate or to its processes to proceed. Accordingly, the processing switches toward the internal loads as directed by the self-verification system.

As illustrated in <FIG>, relays <NUM>-<NUM> are switched on/off in various sequences to provide the associated internal load configuration as needed. In various embodiments, relays <NUM> and <NUM> may be activated or used simultaneously and in parallel to assist in dissipating power and/or heat. On the other hand, relay <NUM> in various embodiments is switched on or used to include phase variations as desired. When a higher voltage RF output is needed, relays <NUM> and <NUM> of the exemplary embodiment are used to switch in a high voltage transformer. Relay <NUM>, in various embodiments, is used or activated to provide the return path or complete the circuit for the self-verification system. In accordance with various embodiments of the present invention, the self-verification system may include a plurality of relays and loads including, for example, resistors, capacitors, inductors and various combinations thereof and as such other relays, loads and combinations thereof are not shown for ease of readability. In some embodiments, the self-verification system may include a timer to ensure that the self-verification system test is not activated or initiated needlessly or is activated as intended. As such, if the electrosurgical generator <NUM> is quickly powered on and off, e.g., in less than a second, the self-verification system does not activate and in various embodiments prevents potential thermal damage to the load such as, for example, resistors. In other embodiments, the timer is configured to start at or near power-on time and reaches or passes a predefined threshold to cause or initiate activation of the self-verification system.

The above description is provided to enable any person skilled in the art to make and use the electrosurgical devices or systems and perform the methods described herein and sets forth the best modes contemplated by the inventors of carrying out their inventions.

Claim 1:
An electrosurgical system for performing surgical procedures comprising:
an electrosurgical generator (<NUM>) adapted to perform a self-verification system test upon activation of the generator, the generator comprising:
a processor (<NUM>) configured to:
cause initiating the self-verification system test;
cause supplying RF energy to a connected electrosurgical hand device (<NUM>, <NUM>'), if a failure of the generator is not detected; and
cause generating a system error if the failure of the generator is detected and a failure threshold is reached; and
a plurality of switchable impedance loads (<NUM>, <NUM>) configured for use during the self-verification system test,
characterized in that
the processor is further configured to cause initiating the self-verification system test after determining a predetermined period of time has elapsed after starting the generator; and
wherein the self-verification system test comprises a verification algorithm verifying the supplied RF energy directed to the plurality of switchable impedance loads across a plurality of RF resolution settings and a plurality of RF regulation modes, wherein for each of the pluralities of RF resolution settings and RF regulation modes the plurality of switchable impedance loads (<NUM>, <NUM>) are set to a specific load configuration.