Patent Description:
Electrosurgery involves application of high radio frequency ("RF") electrical current to a surgical site to cut, ablate, desiccate, or coagulate tissue. In monopolar electrosurgery, a source or active electrode delivers radio frequency alternating current from the RF generator to the targeted tissue. A patient return electrode is placed remotely from the active electrode to conduct the current back to the generator.

In bipolar electrosurgery, return and active electrodes are placed in close proximity to each other such that an electrical circuit is formed between the two electrodes (e.g., in the case of an electrosurgical forceps). In this manner, the applied electrical current is limited to the body tissue positioned between the electrodes. Accordingly, bipolar electrosurgery generally involves the use of instruments where it is desired to achieve a focused delivery of electrosurgical energy between two electrodes positioned on the instrument, e.g. forceps or the like.

Ultrasonic surgical devices have also been demonstrated to provide hemostasis and efficient dissection of tissue with minimum lateral thermal damage and low smoke generation. Unlike electrosurgical devices, which require electrical current to flow through a patient, ultrasonic surgical devices operate by applying mechanical motion through an ultrasonic probe using an ultrasonic transducer that is driven at a resonant frequency <CIT> describes a medical device comprising batteries, a drive circuit, a microprocessor, a gate drive circuit and a bridge signal generator, in which a desired drive waveform is applied either to an ultrasonic transducer or forceps via the drive circuit.

<CIT> relates to a surgical operation system comprising an ultrasound drive power supply apparatus and a high-frequency power supply apparatus. Each of the power supply apparatus has its own power source, amplifier and CPU, wherein the two CPUs are connected with a communication cable.

Each of the electrosurgical and ultrasonic devices has their desired uses due to their inherent operational characteristics. Accordingly, there is a need for a system and a generator configured to operate both types of the instruments to provide for new and improved surgical techniques and applications.

According to a first aspect of the invention there is a surgical generator as recited in claim <NUM> with preferred features as set forth in the dependent claims. An aspect provides a surgical system including a surgical generator in accordance with the first aspect. The invention is defined in appended independent claim <NUM>. Further embodiments are defined in appended dependent claims.

The present disclosure may be understood by reference to the accompanying drawings, when considered in conjunction with the subsequent, detailed description, in which:.

Particular embodiments of the present disclosure will be described below with reference to the accompanying drawings. In the following description, well-known functions or constructions are not described in detail to avoid obscuring the present disclosure in unnecessary detail. Those skilled in the art will understand that the present disclosure may be adapted for use with either an endoscopic instrument, a laparoscopic instrument, or an open instrument. It should also be appreciated that different electrical and mechanical connections and other considerations may apply to each particular type of instrument.

A generator according to the present disclosure can operate with ultrasonic and electrosurgical instruments at multiple frequencies. In particular, the generator may be used in monopolar and/or bipolar electrosurgical procedures, including, for example, cutting, coagulation, ablation, and vessel sealing procedures. The generator may include a plurality of outputs for interfacing with various ultrasonic and electrosurgical instruments (e.g., ultrasonic dissectors and hemostats, monopolar instruments, return electrode pads, bipolar electrosurgical forceps, footswitches, etc.). Further, the generator includes electronic circuitry configured to generate an ultrasonic waveform suitable for driving ultrasonic transducers of ultrasonic instruments and radio frequency energy specifically suited for powering electrosurgical devices operating in various electrosurgical modes (e.g., cut, blend, coagulate, division with hemostasis, fulgurate, spray, etc.) and procedures (e.g., monopolar, bipolar, vessel sealing).

<FIG> is a perspective view of the components of one illustrative embodiment of a dual-output system <NUM> according to the present disclosure. The system <NUM> may include one or more monopolar electrosurgical instruments <NUM> having one or more active electrodes <NUM> (e.g., electrosurgical cutting probe, ablation electrode(s), etc.) for treating tissue of a patient. Electrosurgical alternating RF current is supplied to the instrument <NUM> by a generator <NUM> via a supply line <NUM> that is connected to an active terminal <NUM> (<FIG>) of the generator <NUM>, allowing the instrument <NUM> to cut, coagulate, thermally or non-thermally ablate and/or otherwise treat tissue. The alternating current is returned to the generator <NUM> through a return electrode pad <NUM> via a return line <NUM> at a return terminal <NUM> (<FIG>) of the generator <NUM>. For monopolar operation, the system <NUM> may include a plurality of return electrode pads <NUM> that, in use, are disposed on a patient to minimize the chances of tissue damage by maximizing the overall contact area with the patient. In addition, the generator <NUM> and the return electrode pads <NUM> may be configured for monitoring tissue-to-patient contact to ensure that sufficient contact exists therebetween.

The system <NUM> may also include one or more bipolar electrosurgical instruments, for example, a bipolar electrosurgical forceps <NUM> having one or more electrodes for treating tissue of a patient. The electrosurgical forceps <NUM> includes a housing <NUM> and opposing jaw members <NUM> and <NUM> disposed at a distal end of a shaft <NUM>. The jaw members <NUM> and <NUM> have one or more active electrodes <NUM> and a return electrode <NUM> disposed therein, respectively. The active electrode <NUM> and the return electrode <NUM> are connected to the generator <NUM> through cable <NUM> that includes the supply and return lines <NUM>, <NUM>, which may be coupled to the active and return terminals <NUM>, <NUM>, respectively (<FIG>). The electrosurgical forceps <NUM> is coupled to the generator <NUM> at a port having connections to the active and return terminals <NUM> and <NUM> (e.g., pins) via a plug disposed at the end of the cable <NUM>, wherein the plug includes contacts from the supply and return lines <NUM>, <NUM> as described in more detail below.

The system <NUM> also includes an ultrasonic surgical instrument <NUM>, which includes a housing <NUM> having an ultrasonic transducer <NUM> disposed therein. The ultrasonic surgical instrument <NUM> also includes a waveguide <NUM> having an end effector <NUM> disposed at a distal end thereof. The distal end effector <NUM> includes a movable jaw member <NUM> and a probe <NUM>. The ultrasonic transducer <NUM> is connected to the generator <NUM> via a cable <NUM> that includes supply lines <NUM> and <NUM> coupled to active and return terminals <NUM> and <NUM> (<FIG>), respectively. The ultrasonic probe <NUM> is coupled to the ultrasonic transducer <NUM>, such that when the ultrasonic transducer <NUM> is actuated in response to an ultrasonic waveform from the generator <NUM>, the ultrasonic transducer <NUM> generates ultrasonic mechanical motion within the probe <NUM>, which may be used to seal and/or cut tissue.

With reference to <FIG>, a front face <NUM> of the generator <NUM> is shown. The generator <NUM> may include a plurality of ports <NUM>-<NUM> to accommodate various types of surgical instruments (e.g., monopolar electrosurgical instrument <NUM>, electrosurgical forceps <NUM>, ultrasonic surgical instrument <NUM>, etc.).

The generator <NUM> includes a user interface <NUM> having one or more display screens <NUM>, <NUM>, <NUM> for providing the user with variety of output information (e.g., intensity settings, treatment complete indicators, etc.). Each of the screens <NUM>, <NUM>, <NUM> is associated with a corresponding port <NUM>-<NUM>. The generator <NUM> includes suitable input controls (e.g., buttons, activators, switches, touch screen, etc.) for controlling the generator <NUM>. The screens <NUM>, <NUM>, <NUM> are also configured as touch screens that display a corresponding menu for the instruments (e.g., electrosurgical forceps <NUM>, etc.). The user then adjusts inputs by simply touching corresponding menu options.

Screen <NUM> controls monopolar output and the devices connected to the ports <NUM> and <NUM>. Port <NUM> is configured to couple to a monopolar electrosurgical instrument (e.g., electrosurgical instrument <NUM>) and port <NUM> is configured to couple to a foot switch (not shown). The foot switch provides for additional inputs (e.g., replicating inputs of the generator <NUM>). Screen <NUM> controls monopolar and bipolar output and the devices connected to the ports <NUM> and <NUM>. Port <NUM> is configured to couple to other monopolar instruments. Port <NUM> is configured to couple to a bipolar instrument (not shown).

Screen <NUM> controls the electrosurgical forceps <NUM> and the ultrasonic surgical instrument <NUM> that may be plugged into the ports <NUM> and <NUM>, respectively. The generator <NUM> outputs energy through the port <NUM> suitable for sealing tissue grasped by the electrosurgical forceps <NUM>. In particular, screen <NUM> outputs a user interface that allows the user to input a user-defined intensity setting for each of the ports <NUM> and <NUM>. The user-defined setting may be any setting that allows the user to adjust one or more energy delivery parameters, such as power, current, voltage, energy, etc. or sealing parameters, such as energy rate limiters, sealing duration, etc. The user-defined setting is transmitted to the controller <NUM> where the setting may be saved in memory <NUM>. In embodiments, the intensity setting may be a number scale, such as for example, from one to ten or one to five. In embodiments, the intensity setting may be associated with an output curve of the generator <NUM>. The intensity settings may be specific for each electrosurgical forceps <NUM> being utilized, such that various instruments provide the user with a specific intensity scale corresponding to the electrosurgical forceps <NUM>.

The active and return terminals <NUM> and <NUM> are coupled to ports <NUM>-<NUM> through a hub or switch (not shown). As described in further detail below, the hub or switch couples active and return terminals <NUM> and <NUM> to ports <NUM>-<NUM> depending on what instrument is coupled to the generator and the desired output energy (i.e. ultrasonic or radiofrequency energy).

<FIG> shows a schematic block diagram of the generator <NUM> configured to output both ultrasonic ("US") energy and radiofrequency ("RF") energy. In particular, the generator <NUM> is capable of outputting a low-frequency waveform to the transducer <NUM> (<FIG>) of the ultrasonic surgical instrument <NUM> and a high-frequency waveform to the monopolar electrosurgical instrument <NUM> and/or electrosurgical forceps <NUM>. In embodiments, the generator <NUM> may also configured to simultaneously output low-frequency energy for energizing any suitable electrosurgical instrument and output high-frequency energy for energizing another electrosurgical instrument.

The generator <NUM> includes a controller <NUM>, a power supply <NUM>, and an amplifier <NUM>. The power supply <NUM> may be a high voltage, DC power supply connected to an AC source and provides high voltage, DC power to amplifier <NUM> via leads 227a and 227b, which then converts high voltage, DC power into treatment energy (e.g., electrosurgical or ultrasonic) and delivers the energy to the active terminal <NUM>. The energy is returned thereto via the return terminal <NUM>. Active terminal <NUM> and return terminal <NUM> are coupled to a hub (not shown) which in turn is coupled to the plurality of ports <NUM>-<NUM> of the generator <NUM>. For example, an ultrasonic waveform suitable for driving a transducer <NUM> of an ultrasonic instrument <NUM> is delivered through port <NUM>, or electrosurgical RF energy for energizing the monopolar electrosurgical instrument <NUM> and/or electrosurgical forceps <NUM> may be delivered through ports <NUM> and <NUM>, respectively. The active terminal <NUM> and return terminal <NUM> are coupled to the amplifier <NUM> through an isolation transformer <NUM>. The amplifier <NUM> is configured to operate in a plurality of modes, during which the generator <NUM> outputs corresponding waveforms having specific duty cycles, peak voltages, crest factors, etc. It is envisioned that in other embodiments, the generator <NUM> may be based on other types of suitable power supply topologies. Amplifier <NUM> is a non-resonant amplifier capable of operating over a wide range of frequencies from about <NUM> to <NUM>. A non-resonant amplifier, as used herein, denotes an amplifier lacking any tuning components intended to establish a fixed operating frequency, i.e., inductors, capacitors, etc. The amplifier <NUM> includes transistor drive circuits capable of spanning different switching time periods required to operate over the wide range of frequencies. The amplifier <NUM> also includes switching elements (e.g. transistors and diodes) capable of withstanding peak currents and voltages which vary significantly between the different modes.

The controller <NUM> includes a processor <NUM> operably connected to a memory <NUM>, which may include transitory type memory (e.g., RAM) and/or non-transitory type memory (e.g., flash media, disk media, etc.). The processor <NUM> includes an output port that is operably connected to the power supply <NUM> and/or amplifier <NUM> allowing the processor <NUM> to control the output of the generator <NUM> according to either open and/or closed control loop schemes. A closed loop control scheme is a feedback control loop, in which a plurality of sensors measure a variety of tissue and energy properties (e.g., tissue impedance, tissue temperature, output power, current and/or voltage, etc.), and provide feedback to the controller <NUM>. The controller <NUM> then signals the power supply <NUM> and/or amplifier <NUM>, which adjusts the DC and/or power supply, respectively. Those skilled in the art will appreciate that the processor <NUM> may be substituted for by using any logic processor (e.g., control circuit) adapted to perform the calculations and/or set of instructions described herein including, but not limited to, field programmable gate array, digital signal processor, and combinations thereof.

The generator <NUM> according to the present disclosure includes a plurality of sensors <NUM>, e.g., a current sensor 280a, a voltage sensor 280b, or a power sensor (not shown). The plurality of sensors are designed with sufficient bandwidth to accurately measure across the wide range of frequencies which the amplifier <NUM> can operate. Various components of the generator <NUM>, namely, the amplifier <NUM>, the current and voltage sensors 280a and 280b, may be disposed on a printed circuit board (PCB). The current sensor 280a is coupled to the active terminal <NUM> and provides measurements of the current supplied by the amplifier <NUM>. The voltage sensor 280b is coupled to the active and return terminals <NUM> and <NUM> provides measurements of the voltage supplied by the amplifier <NUM>. In embodiments, the current and voltage sensors 280a and 280b may be coupled to active and return leads 228a and 228b, which interconnect the active and return terminals <NUM> and <NUM> to the amplifier <NUM>, respectively.

The current and voltage sensors 280a and 280b provide the sensed voltage and current signals, respectively, to the controller <NUM>, which then may adjust output of the power supply <NUM> and/or the amplifier <NUM> in response to the sensed voltage and current signals. The controller <NUM> also receives input signals from the input controls of the generator <NUM>, the electrosurgical instrument <NUM>, electrosurgical forceps <NUM>, and/or ultrasonic surgical instrument <NUM>, including, for example, a desired displacement <NUM> of the ultrasonic surgical instrument <NUM>. The controller <NUM> utilizes the input signals to adjust power outputted by the generator <NUM> and/or performs other control functions thereon.

With reference to <FIG>, the controller <NUM> of generator <NUM> includes two control sections, namely, an electrosurgical controller <NUM> and an ultrasonic controller <NUM>. The control signals output by both the electrosurgical controller <NUM> and an ultrasonic controller <NUM> pass through a switch <NUM> prior to signaling the power supply <NUM> and/or amplifier <NUM>. The switch <NUM> controls which control signal (i.e., electrosurgical control signals or ultrasonic control signals) to pass to control the amplifier <NUM> and/or power supply <NUM>. Control signals may be pulse width modulated signals as described in further detail below. The switch <NUM> can either be manually set by a user by selecting a desired output on the user interface <NUM> of the generator <NUM>, or automatically by the controller <NUM>, which may be based on a type of instrument being coupled to the generator <NUM>. In embodiments, if the ultrasonic instrument <NUM> is coupled to port <NUM>, the switch <NUM> is activated to pass ultrasonic control signals from the ultrasonic controller <NUM>. Alternatively, if a monopolar electrosurgical instrument <NUM> or electrosurgical forceps <NUM> are coupled to ports <NUM> and <NUM>, respectively, switch <NUM> is activated to pass electrosurgical control signals from electrosurgical controller <NUM>.

The electrosurgical controller <NUM> is configured to control the amplifier <NUM> to output an electrosurgical RF waveform in at least one of constant current, constant voltage, or constant power modes. In particular, the electrosurgical controller <NUM> compares the output voltage "vout" and the output current "iout" to determine the desired operation of the generator <NUM> (e.g., constant current, constant voltage, or constant power). The mode selection is generally based on the impedance associated with the tissue being cut. Different types of tissue, such as muscle and fat, have different impedances. In terms of electrosurgical operations, constant power output tends to uniformly vaporize tissue, resulting in clean dissection. Whereas constant voltage output tends to explosively vaporize or carbonize tissue ("black coagulation"), and constant current output tends to thermally coagulate tissue without vaporization ("white coagulation"). Carbonization is surgically useful if the surgeon wishes to rapidly destroy surface tissue, and thermal coagulation is regularly coupled with mechanical pressure to seal hepatic or lymphatic vessels shut. However, the surgeon generally desires to operate using constant power output and return to using constant power output as quickly as possible if there is deviation.

Similar to the electrosurgical controller <NUM>, the ultrasonic controller <NUM> also receives measured output current "iout" at the active terminal <NUM> and return terminal <NUM>. However, the components of the ultrasonic controller <NUM> portion of the controller <NUM> differ. The ultrasonic controller <NUM> includes a motional bridge <NUM>, a proportional-integral-derivative ("PID") controller <NUM>, a pulse-width modulator ("PWM") <NUM>, a frequency control unit <NUM> and a filter <NUM>. Unlike electrosurgical generators, which run at a fixed frequency defined by a system clock and where the exact frequency is not of particular importance, ultrasonic devices may include a control mechanism to precisely track the resonant frequency of the transducer <NUM> down to single-digit-Hertz and to adjust the operating frequency of the generator to match the resonant frequency. The motional bridge <NUM> measures the mechanical motion of the ultrasonic transducer <NUM> and provides a motional feedback signal representing the mechanical motion of the ultrasonic transducer <NUM>. In particular, the motional bridge <NUM> produces a feedback signal in proportion to and in phase with the mechanical motion of the transducer <NUM> and waveguide <NUM>. The output signal of the motional bridge <NUM> is compared with a desired displacement <NUM> of the mechanical motion of the ultrasonic transducer <NUM>. The desired displacement <NUM> may be determined automatically based on the desired output frequency of the ultrasonic surgical instrument <NUM> or can be set manually by a user, for example, by selecting a HI/LOW switch/button (not shown) on the user interface <NUM> of the generator <NUM> or on the ultrasonic surgical instrument <NUM>. The combined signal from the desired displacement <NUM> and the motional bridge <NUM> is received by the PID controller <NUM>. The PID controller <NUM> performs frequency-shifting of the output signal to generate a corrected control signal based on a comparison of the motional feedback signal generated by the motional bridge <NUM> and the desired displacement <NUM>. The PWM <NUM> controls the frequency of the output waveform and maintains a constant ultrasonic amplitude of the control signal through modulation of the duty cycle.

In addition to error correction by the PID controller <NUM>, a frequency control unit <NUM> adjusts the frequency of the control signal to remain at the resonant frequency of the ultrasonic instrument <NUM>. The frequency control unit <NUM> further comprises a filter <NUM> configured to filter out unwanted frequencies. In particular, filter <NUM> may comprise a high pass and/or low pass filter. The modulated control signals from the PWM <NUM> and frequency control unit <NUM> are received by the signal generator <NUM> to generate an ultrasonic control signal.

The switch <NUM> receives the electrosurgical control signal from the electrosurgical controller <NUM> and/or the ultrasonic control signal from the ultrasonic controller <NUM>. Depending on the type of the instrument coupled to the generator <NUM>, the amplifier <NUM> and/or power supply <NUM> receives either the electrosurgical control signal or the ultrasonic control signal from the switch <NUM>.

Claim 1:
A surgical generator (<NUM>), comprising:
a power supply (<NUM>);
an amplifier (<NUM>) coupled to the power supply and configured to output a first waveform and a second waveform;
a controller (<NUM>) coupled to the amplifier and configured to provide at least one of a first control signal and a second control signal to the amplifier, the controller including:
a first controller configured to provide the first control signal to the amplifier to generate the first waveform;
a second controller configured to provide the second control signal to the amplifier to generate the second waveform; and
a switch (<NUM>) configured to receive and select at least one of the first control signal and the second control signal to be provided to the amplifier and to the power supply wherein the first controller is an electrosurgical controller (<NUM>) and the first control signal is an RF control signal wherein the second controller is an ultrasonic controller (<NUM>) and the second control signal is an ultrasonic control signal.