Abstract: Various aspects of a generator, ultrasonic device, and method for estimating and controlling a state of an end effector of an ultrasonic device are disclsoed. The ultrasonic device includes an electromechanical ultrasonic system defined by a predetermined resonant frequency, including an ultrasonic transducer coupled to an ultrasonic blade. A control circuit measures a complex impedance of an ultrasonic transducer, wherein the complex impedance is defined as Z g ? ( t ) = V g ? ( t ) I g ? ( t ) . The control circuit receives a complex impedance measurement data point and compares the complex impedance measurement data point to a data point in a reference complex impedance characteristic pattern. The control circuit then classifies the complex impedance measurement data point based on a result of the comparison analysis and assigns a state or condition of the end effector based on the result of the comparison analysis.

Abstract: A method of determining instability of an ultrasonic blade includes monitoring a phase angle ? between voltage Vg(t) and current Ig(t) signals applied to an ultrasonic transducer, coupled to an ultrasonic blade via an ultrasonic waveguide, inferring the blade temperature based on the phase angle ?, comparing the inferred temperature to an ultrasonic blade instability trigger point threshold, and adjusting a power level applied to the ultrasonic transducer to modulate the temperature of the blade. The method may also include determining a frequency/temperature relationship of an ultrasonic blade that exhibits a displacement or modal instability and compensating for a thermal induced instability of the ultrasonic blade. The method may be implemented in an ultrasonic surgical instrument or by a control circuit in a power generator for the ultrasonic surgical instrument.

Abstract: Methods, devices, and systems for measuring impedance for electrosurgical tools are provided. In general, a surgical device configured to apply energy to tissue can be configured to deliver the energy to the tissue based on an impedance of the tissue. The impedance can be determined based on an electrical signal transmitted to the tissue via the surgical device, such as by one or more electrodes of the surgical device that are in contact with the tissue. The impedance determination can include determining both real and imaginary components of the impedance, thereby allowing a phase shift to be identified and for an actual impedance to be determined by correcting for the phase shift. The actual impedance of the tissue can be used to identify a type of the tissue.

Abstract: A method of determining an initial temperature of an ultrasonic blade may include measuring a resonant frequency of an ultrasonic blade prior to activating an ultrasonic transducer, in which the ultrasonic transducer is coupled to the blade via an ultrasonic waveguide, comparing the measured resonant frequency to a baseline resonant frequency, determining an initial temperature of the ultrasonic blade based on a difference between the measured resonant frequency and the baseline resonant frequency, and applying a power level to the blade based on the initial temperature of the blade. The method may further include applying a high power level to the transducer when the initial temperature of the ultrasonic blade is low or applying a low power level to the transducer when the initial temperature of the blade is high. The baseline resonant frequency may be stored in a memory look up table.

Abstract: A method of ultrasonic sealing includes activating an ultrasonic blade temperature sensing, measuring a first resonant frequency of an ultrasonic electromechanical system that includes a transducer coupled to the blade via a waveguide, making a first comparison between the measured first resonant frequency and a first predetermined resonant frequency, and adjusting a power level applied to the transducer based on the first comparison. The first predetermined frequency may correspond to an optimal tissue coagulation temperature. The method may further include measuring a second resonant frequency of the system, making a second comparison between the measured second frequency and a second predetermined frequency, and adjusting the power level based on the second comparison. The second predetermined frequency may correspond a melting point temperature of a clamp arm pad. An ultrasonic instrument and a generator may implement the method.

Abstract: An ultrasonic device may include an electromechanical ultrasonic system that includes an ultrasonic transducer coupled to an ultrasonic blade. A method of delivering energy to the ultrasonic device may include sensing a vessel type in contact with the blade, determining that the vessel type is either a vein or an artery, and delivering power to the transducer based on the vessel type. Power may be applied to the transducer at a power level P that differs from a nominal power level Pn for a period T that differs from a nominal period Tn based on the vessel. The power level P may be lower than Pn for a period T that is longer than Tn when the vessel is a vein. Alternatively, the power level P my be greater than Pn for a period T that is shorter than Tn when the vessel is an artery.

Abstract: Various aspects of a generator, ultrasonic device, and method for estimating a state of an end effector of an ultrasonic device are disclosed. The ultrasonic device includes an electromechanical ultrasonic system defined by a predetermined resonant frequency, including an ultrasonic transducer coupled to an ultrasonic blade. A control circuit measures a complex impedance of an ultrasonic transducer, wherein the complex impedance is defined as Z g ? ( t ) = V g ? ( t ) I g ? ( t ) . The control circuit receives a complex impedance measurement data point and compares the complex impedance measurement data point to a data point in a reference complex impedance characteristic pattern. The control circuit then classifies the complex impedance measurement data point based on a result of the comparison analysis and assigns a state or condition of the end effector based on the result of the comparison analysis.

Abstract: Various systems and methods for determining the composition of tissue via an ultrasonic surgical instrument are disclosed. A control circuit can be configured to monitor the change in resonant frequency of an ultrasonic electromechanical system of the ultrasonic surgical instrument as the ultrasonic blade oscillates against a tissue and determine the composition of the tissue accordingly. In some aspects, the control circuit can be configured to modify the operation of the ultrasonic electromechanical system or other operational parameters of the ultrasonic surgical instrument according to the detected tissue composition.

Abstract: A return pad of an electrosurgical system is disclosed. The return pad includes a plurality of conductive members and a plurality of sensing devices. The conductive members are configured to receive radio frequency current applied to a patient. The sensing devices are configured to detect at least one of the following: a nerve control signal applied to the patient; and a movement of an anatomical feature of the patient resulting from application of the nerve control signal.

Abstract: A method for controlling an operation of an ultrasonic blade of an ultrasonic electromechanical system is disclosed. The method includes providing an ultrasonic electromechanical system comprising an ultrasonic transducer coupled to an ultrasonic blade via an ultrasonic waveguide; applying, by an energy source, a power level to the ultrasonic transducer; determining, by a control circuit coupled to a memory, a mechanical property of the ultrasonic electromechanical system; comparing, by the control circuit, the mechanical property with a reference mechanical property stored in the memory; and adjusting, by the control circuit, the power level applied to the ultrasonic transducer based on the comparison of the mechanical property with the reference mechanical property.

Abstract: An electrosurgical device may include a controller including an electrical generator, a surgical probe having a distal active electrode in electrical communication with an electrical source terminal of the electrical generator, and a return pad in electrical communication with an electrical return terminal of the electrical generator. The electrical generator may be configured to source an electrical current from the electrical source terminal, in which the electrical current combines characteristics of a therapeutic electrical signal and characteristics of an excitable tissue stimulating signal. The device may be configured to determine a distance from the electrode to an excitable tissue, based at least in part on an output signal generated by a sensing device in the pad. The device may also be configured to alter one or more characteristics of the therapeutic signal when the distance from the electrode to the tissue is less than a predetermined value.

Abstract: A method for characterizing a state of an end effector of an ultrasonic device is disclosed. The ultrasonic device including an electromechanical ultrasonic system defined by a predetermined resonant frequency. The electromechanical ultrasonic system further including an ultrasonic transducer coupled to an ultrasonic blade. The method including applying, by an energy source, a power level to the ultrasonic transducer; measuring, by a control circuit coupled to a memory, an impedance value of the ultrasonic transducer; comparing, by the control circuit, the impedance value to a reference impedance value stored in the memory; classifying, by the control circuit, the impedance value based on the comparison; characterizing, by the control circuit, the state of the electromechanical ultrasonic system based on the classification of the impedance value; and adjusting, by the control circuit, the power level applied to the ultrasonic transducer based on the characterization of the state of the end effector.

Abstract: Various systems and methods for determining the state of an ultrasonic electromechanical system are disclosed. A control circuit can be configured to monitor the change in resonant frequency of an ultrasonic electromechanical system of the ultrasonic surgical instrument as the ultrasonic blade oscillates and determine the state or change in state of the ultrasonic electromechanical system accordingly. The change in state of the ultrasonic electromechanical system can include, for example, the change in temperature of the system. In some aspects, the control circuit can be configured to modify the operation of the ultrasonic electromechanical system or other operational parameters of the ultrasonic surgical instrument according to the state or change in state of the system.

Abstract: A generator, ultrasonic device, and method of determining a temperature of an ultrasonic blade are disclosed. A control circuit coupled to a memory determines an actual resonant frequency of an ultrasonic electromechanical system comprising an ultrasonic transducer coupled to an ultrasonic blade by an ultrasonic waveguide. The actual resonant frequency is correlated to an actual temperature of the ultrasonic blade. The control circuit retrieves from the memory a reference resonant frequency of the ultrasonic electromechanical system. The reference resonant frequency is correlated to a reference temperature of the ultrasonic blade. The control circuit then infers the temperature of the ultrasonic blade based on the difference between the actual resonant frequency and the reference resonant frequency.

Abstract: An ultrasonic surgical instrument and method of sealing tissue includes interrogating the tissue with an electrical signal and adjusting an electrical parameter of at least one of the ultrasonic energy or the RF energy in response to the tissue feedback to inhibit transecting the tissue. The ultrasonic surgical instrument has an end effector, a shaft assembly, a body, and a power controller. The power controller is operatively connected to the ultrasonic blade and the RF electrode and configured to direct activation of the ultrasonic blade or the RF electrode. The power controller is further configured to interrogate the tissue with the electrical signal via the ultrasonic blade or the RF electrode to provide a tissue feedback and adjust an electrical parameter of the ultrasonic energy or the RF energy in response to the tissue feedback to inhibit transecting the tissue.

Abstract: An ultrasonic surgical instrument and method of limiting an ultrasonic blade temperature includes adjusting at least one power parameter of the ultrasonic energy in response to reaching a predetermined frequency parameter change threshold in the ultrasonic blade limiting the temperature of the ultrasonic blade to an upper temperature limit. The ultrasonic surgical instrument further includes an end effector having an ultrasonic blade, a jaw, and a controller. The jaw is movably positioned relative to the ultrasonic blade and configured to move between an open position and a closed position. The controller operatively connects to the ultrasonic blade and is configured to measure an ultrasonic frequency of the ultrasonic blade. The controller has a memory including a plurality of predetermined data correlations that correlate changes in measured ultrasonic frequency of the ultrasonic blade to a blade temperature of the ultrasonic blade.

Abstract: An electrosurgical system includes an RF current generator, a handle body, and an end effector. The end effector may include a first and a second energy delivery surface. At least a portion of either first or second energy delivery surfaces, or both, may include one or more patterned coatings of an electrically non-conducting non-stick material. The material may be deposited on a surface of, within a depression in, or on features extending from the energy surfaces, or through an overmolding process. The patterned coating may be formed from a coating of the material from which portions have been removed. An energy delivery surface has a first area, and the patterned coating has a second area. A ratio of the second area to the first area may be less than or equal to about 0.9, less than or equal to about 0.7, or less than or equal to about 0.5.

Abstract: A surgical instrument includes an end effector that has an ultrasonic blade and a clamp arm that is movable relative to the ultrasonic blade from an opened position toward a closed position. The ultrasonic blade and the clamp arm are able to receive tissue in the opened position, and the clamp arm is able to clamp tissue against the ultrasonic blade in the closed position. There is a first electrode connected with the clamp arm, and a second electrode associated with the ultrasonic blade. The electrodes are able to apply bipolar radiofrequency (RF) energy to tissue captured in the end effector. The instrument further has a first button for activating the ultrasonic blade to provide a cutting and sealing mode at the end effector. There is also a second button for activating the electrodes to provide a spot coagulation mode at the end effector.

Abstract: Aspects of the present disclosure are presented for a single surgical instrument configured to grasp, seal, and/or cut tissue through application of therapeutic energy, and also detect nerves through application of non-therapeutic electrical energy. A medical device may include two jaws at an end effector, used to apply therapeutic energy and to perform surgical procedures. The therapeutic energy may be in the form of ultrasonic vibrations or higher voltage electrosurgical energy. One of the jaws may be configured to cut tissue through application of the blade. In addition, one or both of the two jaws may be configured to apply nontherapeutic energy for nerve stimulation probing. The application of therapeutic energy may be disabled while the nontherapeutic nerve stimulation energy is applied, and vice versa. The nontherapeutic nerve stimulation energy may be applied to the use of one or more probes positioned near one or both of the jaws.