Abstract: Disclosed is a method of generating electrical signal waveforms by a generator. The generator includes a processor and a memory in communication with the processor. The memory defines a first and second table. The processor retrieves information from the first table defined in the memory, where the information is associated with a first wave shape of a first electrical signal waveform for performing a surgical procedure. The processor retrieves information from the second table defined in the memory, where the information is associated with a second wave shape of a second electrical signal waveform for performing a surgical procedure. The processor combines the first and second wave shapes to create a combined wave shape of an electrical signal waveform for performing a surgical procedure and the combined wave shape electrical signal waveform for performing a surgical procedure is delivered to a surgical instrument.

Abstract: A method of generating electrical signal waveforms. A generator includes a digital processing circuit, a memory circuit in communication with the digital processing circuit defining a lookup table, a digital synthesis circuit in communication with the digital processing circuit and the memory circuit, and a digital-to-analog converter (DAC) circuit. The method includes generating a first and second digital electrical signal waveforms, combining the first and second waveforms to form a combined waveform, modifying the combined waveform to form a modified waveform The peak amplitude of the modified waveform does not exceed a predetermined amplitude value. The method includes generating a second waveform that is a function of the first waveform. The method includes modifying a frequency of the first waveform to form a frequency modified first waveform and combining the frequency modified first and second waveforms to form a combined waveform.

Abstract: Disclosed is a method for operating a surgical instrument, the surgical instrument comprising a radio frequency (RF) energy output, an ultrasonic energy output, and a first jaw and a second jaw configured for pivotal movement between a closed position and an open position, the method comprising: receiving a first input indicating a user selection of one of a first option and a second option; receiving a second input indicating whether the first jaw and the second jaw are in the closed position or in the open position; receiving a third input indicating electrical impedance at the RF energy output; and selecting a mode of operation for treating a tissue from a plurality of modes of operation based at least in part on the first input, the second input and the third input.

Abstract: Disclosed is a method of generating electrical signal waveforms by a generator. The method includes storing phase points of first and second digital electrical signal waveforms in first and second lookup tables. The first and second digital electrical signal waveforms are represented by a predetermined number of phase points that define wave shapes. At each clock cycle, a digital synthesis circuit retrieves phase points from the first and second lookup tables and the digital processing circuit combines phase points from the first and second lookup tables. A digital-to-analog converter (DAC) circuit converts the combined phase point into an analog signal. The analog signal is configured to drive a first and second ultrasonic transducer.

Abstract: Disclosed is a system comprising a generator and a surgical instrument, wherein the generator is configured to deliver a combined signal comprising a radio frequency (RF) component and an ultrasonic component to the surgical instrument; and the surgical instrument comprises: an RF energy output, an ultrasonic energy output, a circuit configured to steer the RF component to the RF energy output and steer the ultrasonic component to the ultrasonic energy output, wherein the generator is configured to adjust a frequency of the RF component based on a characterization of a circuit component of the circuit.

Abstract: Provided is a method for managing radio frequency (RF) and ultrasonic signals output by a generator that includes a surgical instrument comprising an RF energy output and an ultrasonic energy output and a circuit configured to receive a combined RF and ultrasonic signal from the generator. The method includes receiving a combined radio frequency (RF) and ultrasonic signal from a generator, generating a RF filtered signal by filtering RF frequency content from the combined signal; filtering ultrasonic frequency content from the combined signal; generating an ultrasonic filtered signal; providing the RF filtered signal to the RF energy output; and providing the ultrasonic filtered signal to the ultrasonic energy output.

Abstract: Provided is an apparatus, system, and method for managing radio frequency (RF) and ultrasonic signals output by a generator that includes a surgical instrument comprising an RF energy output and an ultrasonic energy output and a circuit configured to receive a combined RF and ultrasonic signal from the generator. The circuit may be configured to isolate a direct current (DC) voltage from the combined RF and ultrasonic signal. The DC voltage may then be used to power various electrical components of the surgical instrument while still providing RF energy and ultrasonic energy for surgical application.

Abstract: A surgical device. The surgical device may comprise a transducer, an end effector, a generator and a control circuit. The transducer may be configured to provide vibrations. The end effector may be coupled to the transducer and may extend from the transducer along the longitudinal axis. The generator may provide an electrical signal to the transducer. Also, the control circuit may modify a current amplitude of the electrical signal in response to a change in a vibration frequency of the end effector. Accordingly to various embodiments, the control circuit may detect a first contribution to a vibration frequency of the end effector, the first contribution originating from tissue in contact with the end effector. Also, according to various embodiments, the control circuit may indicate a change in a vibration frequency of the end effector.

Abstract: Various embodiments are directed to an electrosurgical systems and methods for providing an electrosurgical signal to a patient. An electrosurgical signal defining a plurality of pulses may be provided to first and second electrodes. A first reading may be received indicating an impedance between the first and second electrodes taken at a first point of a first pulse of the electrosurgical signal. A second reading may indicate the impedance a first point of a second pulse of the electrosurgical signal, where the first point of the first pulse and the first point of the second pulse are at equivalent positions within the first and second pulses. Based on a comparison of the first reading and the second reading, a short circuit may be determined and a signal indicating the short circuit may be generated.

Abstract: A method for coagulating and dissecting tissue. The method includes measuring a tissue property and delivering multiple energy modalities to the tissue based on the tissue property. The energy modalities being delivered from a generator either alone or in combination.

Abstract: Various forms are directed to systems and methods for dissection and coagulation of tissue. A method for detecting a short circuit in a surgical system configured to apply radio frequency energy and ultrasonic energy to a target surgical site that includes delivering radio frequency (RF) energy to an electrode of a surgical instrument, transitioning from delivering the RF energy to delivering ultrasonic energy to an ultrasonic blade of the surgical instrument, delivering an exploratory ultrasonic pulse to the ultrasonic blade, measuring an ultrasonic property of tissue engaged by the surgical instrument, wherein the ultrasonic property is associated with the exploratory ultrasonic pulse, determining whether the measured ultrasonic property is consistent with a behavior of low impedance tissue, and delivering ultrasonic energy to the ultrasonic blade to cut the tissue upon determining that the measured ultrasonic property is consistent with ultrasonic energy being applied to low impedance tissue.

Abstract: A surgical instrument including a transducer and an end effector is disclosed. The transducer may be configured to generate an acoustic standing wave of vibratory motion along a longitudinal axis and may include a piezoelectric stack positioned along the longitudinal axis. A length of the transducer may be less than ½ of the wavelength of the acoustic standing wave. The end effector may be acoustically coupled to and may extend distally from the transducer along the longitudinal axis. A sum of the length of the transducer and a length of the end effector may be an integer multiple of ½ of the wavelength of the acoustic standing wave.

Abstract: Various embodiments are directed to a method of driving an end effector coupled to an ultrasonic drive system of a surgical instrument. The method comprises generating at least one electrical signal. The at least one electrical signal is monitored against a first set of logic conditions. A first response is triggered when the first set of logic conditions is met. A parameter is determined from the at least one electrical signal.

Abstract: A surgical device. The surgical device may comprise a transducer, an end effector, a generator and a control circuit. The transducer may be configured to provide vibrations. The end effector may be coupled to the transducer and may extend from the transducer along the longitudinal axis. The generator may provide an electrical signal to the transducer. Also, the control circuit may modify a current amplitude of the electrical signal in response to a change in a vibration frequency of the end effector. Accordingly to various embodiments, the control circuit may detect a first contribution to a vibration frequency of the end effector, the first contribution originating from tissue in contact with the end effector. Also, according to various embodiments, the control circuit may indicate a change in a vibration frequency of the end effector.

Abstract: A surgical instrument. The surgical instrument may comprise a transducer and an end effector. The transducer may be configured to provide vibrations along a longitudinal axis at a predetermined frequency and may comprise a piezoelectric stack positioned along the longitudinal axis. The transducer also may comprise a first metallic end mass positioned along the longitudinal axis adjacent a first end of the piezoelectric stack and a second metallic end mass positioned along the longitudinal axis adjacent a second end of the piezoelectric stack. The length of the transducer may be greater than or equal to of one wavelength and less than ½ of one wavelength. The end effector may be coupled to the transducer and may extend along the longitudinal axis. The length of the transducer and the end effector may be a multiple of ½ of one wavelength.

Abstract: Various forms are directed to systems and methods for driving an end effector coupled to an ultrasonic drive system of a surgical instrument. A generator may generate at least one electrical signal. The at least one electrical signal may be monitored against a first set of logic conditions. When an ultrasonic impedance of the surgical instrument exceeds a threshold impedance, a resonant frequency of the at least one electrical signal may be stored as a baseline frequency. A first response of the generator may be triggered upon the occurrence of either the first set of logic conditions being met or the resonant frequency of the at least one electrical signal differing from the baseline frequency by a baseline deviation threshold.

Abstract: Various embodiments are directed to systems and methods for providing a drive signal to a surgical device for treating tissue. A surgical generator may deliver the drive signal according to a first composite load curve. The surgical generator may receive a first tissue measurement indicating a property of the tissue at a first time during the delivery of the drive signal, receive a second tissue measurement indicating the property of the tissue at a second time during the delivery of the drive signal after the first time, and based on the first and second tissue measurements, determine a difference in the property of the tissue between the first time and the second time. When the difference in the property of the tissue exceeds a difference threshold, the generator may deliver the drive signal according to a second composite load curve that is more aggressive than the first composite load curve.

Abstract: Various forms are directed to systems and methods for driving an end effector coupled to an ultrasonic drive system of a surgical instrument. A generator may generate at least one electrical signal. The at least one electrical signal may be monitored against a first set of logic conditions. When an ultrasonic impedance of the surgical instrument exceeds a threshold impedance, a resonant frequency of the at least one electrical signal may be stored as a baseline frequency. A first response of the generator may be triggered upon the occurrence of either the first set of logic conditions being met or the resonant frequency of the at least one electrical signal differing from the baseline frequency by a baseline deviation threshold.

Abstract: A method for controlling a waveform shape of a motional branch current in an ultrasonic transducer of a surgical device. The method may comprise generating a transducer drive signal by selectively recalling, using a direct digital synthesis (DDS) algorithm, drive signal waveform samples stored in a look-up table (LUT), generating samples of current and voltage of the transducer drive signal when the transducer drive signal is communicated to the surgical device, determining samples of the motional branch current based on the current and voltage samples, a static capacitance of the ultrasonic transducer and a frequency of the transducer drive signal, comparing each sample of the motional branch current to a respective target sample of a target waveform to determine an error amplitude, and modifying the drive signal waveform samples stored in the LUT such that an amplitude error between subsequent samples of the motional branch current and respective target samples is reduced.

Abstract: Various embodiments are directed to a method of driving an end effector coupled to an ultrasonic drive system of a surgical instrument. In accordance with the method, a generator is configured to generate at least one time varying electrical signal having a resonant frequency, monitor the resonant frequency of the at least one electrical signal, calculate a frequency slope between frequency data points of the time varying electrical signal, where the frequency slope is the change in resonant frequency over time, compare the frequency slope to a threshold frequency slope, and trigger a first response of the generator when the frequency slope crosses the threshold frequency slope.