An ultrasonic device may include an electromechanical ultrasonic system defined by a predetermined resonant frequency, in which the system may include an ultrasonic transducer coupled to an ultrasonic blade. A method of estimating a state of an end effector of the ultrasonic device may include applying a drive signal defined by a magnitude and a frequency to the ultrasonic transducer, sweeping the frequency of the drive signal from below a first resonance to above the first resonance of the electromagnetic ultrasonic system, measuring and recording, impedance/admittance circle variables R.sub.e, G.sub.e, X.sub.e, and B.sub.e, comparing, the measured impedance/admittance circle variables R.sub.e, G.sub.e, X.sub.e, and B.sub.e to reference impedance/admittance circle variables R.sub.ref, G.sub.ref, X.sub.ref, and B.sub.ref, and determining, a state or condition of the end effector based on the result of the comparison. An electromechanical ultrasonic system may include a control circuit to effect the method.

An ultrasonic device may include an electromechanical system defined by a resonant frequency and further include an ultrasonic transducer coupled to an ultrasonic blade. The device may be composed of two or more components, one of which is reusable and one of which is disposable. A method of detecting a proper installation of the components may include determining a spectroscopy signature of the blade coupled to the transducer, comparing the signature to a reference signature, determining an installation state of the components based on the comparison, and controlling a delivery of power to the transducer based on the comparison. The method may include enabling an operation of the device when the installation state of components is proper. The method may further include disabling the device when the installation state is not proper and generating a warning. The warning may be visible, audible, or tactile.

An ultrasonic device may include an electromechanical ultrasonic system defined by a predetermined resonant frequency and include an ultrasonic transducer coupled to an ultrasonic blade. A method of delivering energy to the device may include applying energy to the blade at a first power level via the transducer coupled to the blade, measuring a complex impedance of the transducer, receiving a complex impedance feedback data point, comparing the complex impedance feedback data point to a reference complex impedance characteristic pattern, and determining that the blade is contacting a vessel based on the comparison. The method may also include disabling the power applied to the transducer and switching to a lower power level. The method may further include generating a warning that the blade is contacting a vessel, such as a light or a sound. An ultrasonic surgical instrument may effect the method.

An ultrasonic device may include an electromechanical ultrasonic system defined by a predetermined resonant frequency, the electromechanical ultrasonic system including an ultrasonic transducer coupled to an ultrasonic blade. A method of controlling energy delivered to the ultrasonic device may include determining an impedance of the ultrasonic transducer during a transection process, analyzing the impedance of the ultrasonic transducer, profiling the ultrasonic blade based on the impedance, and adjusting a power delivered to the transducer during the transection process based on the profile of the blade. The method may further include pulsing, the power delivered to the ultrasonic transducer, determining changes in tissue characteristics of tissue located in an end effector, wherein the changes in tissue characteristics is determined between pulses, and adjusting power delivered to the ultrasonic transducer based on the tissue changes throughout the transection. An ultrasonic instrument may include components configured to effect the method.

An ultrasonic device may include an electromechanical ultrasonic system defined by a predetermined resonant frequency, the electromechanical ultrasonic system having an ultrasonic transducer coupled to an ultrasonic blade. A method of compensating power delivered to the ultrasonic device may include determining an articulation angle of an articulatable ultrasonic blade coupled to the ultrasonic transducer, adjusting a complex impedance of the ultrasonic transducer to compensate for power lost as a function of the articulation angle, and adjusting, a power applied to the ultrasonic transducer based on the articulation angle. The ultrasonic device may include a generator and a control circuit configured to effect the method.

An ultrasonic device may include an electromechanical ultrasonic system defined by a predetermined resonant frequency, the electromechanical ultrasonic system including an ultrasonic transducer coupled to an ultrasonic blade. A method of controlling energy delivered to the ultrasonic device may include determining an impedance of the ultrasonic transducer during a transection process, analyzing the impedance of the ultrasonic transducer, profiling the ultrasonic blade based on the impedance, and adjusting a power delivered to the transducer during the transection process based on the profile of the blade. The method may further include pulsing, the power delivered to the ultrasonic transducer, determining changes in tissue characteristics of tissue located in an end effector, wherein the changes in tissue characteristics is determined between pulses, and adjusting power delivered to the ultrasonic transducer based on the tissue changes throughout the transection. An ultrasonic instrument may include components configured to effect the method.

An ultrasonic device may include an electromechanical system defined by a resonant frequency and further include an ultrasonic transducer coupled to an ultrasonic blade. The device may be composed of two or more components, one of which is reusable and one of which is disposable. A method of detecting a proper installation of the components may include determining a spectroscopy signature of the blade coupled to the transducer, comparing the signature to a reference signature, determining an installation state of the components based on the comparison, and controlling a delivery of power to the transducer based on the comparison. The method may include enabling an operation of the device when the installation state of components is proper. The method may further include disabling the device when the installation state is not proper and generating a warning. The warning may be visible, audible, or tactile.

An ultrasonic device may include an electromechanical ultrasonic system defined by a predetermined resonant frequency, in which the system may include an ultrasonic transducer coupled to an ultrasonic blade. A method of estimating a state of an end effector of the ultrasonic device may include applying a drive signal defined by a magnitude and a frequency to the ultrasonic transducer, sweeping the frequency of the drive signal from below a first resonance to above the first resonance of the electromagnetic ultrasonic system, measuring and recording, impedance/admittance circle variables R.sub.e, G.sub.e, X.sub.e, and B.sub.e, comparing, the measured impedance/admittance circle variables R.sub.e, G.sub.e, X.sub.e, and B.sub.e to reference impedance/admittance circle variables R.sub.ref, G.sub.ref, X.sub.ref, and B.sub.ref, and determining, a state or condition of the end effector based on the result of the comparison. An electromechanical ultrasonic system may include a control circuit to effect the method.

An ultrasonic device may include an electromechanical ultrasonic system defined by a predetermined resonant frequency and include an ultrasonic transducer coupled to an ultrasonic blade. A method of delivering energy to the device may include applying energy to the blade at a first power level via the transducer coupled to the blade, measuring a complex impedance of the transducer, receiving a complex impedance feedback data point, comparing the complex impedance feedback data point to a reference complex impedance characteristic pattern, and determining that the blade is contacting a vessel based on the comparison. The method may also include disabling the power applied to the transducer and switching to a lower power level. The method may further include generating a warning that the blade is contacting a vessel, such as a light or a sound. An ultrasonic surgical instrument may effect the method.

An ultrasonic device may include an electromechanical ultrasonic system defined by a predetermined resonant frequency, the electromechanical ultrasonic system having an ultrasonic transducer coupled to an ultrasonic blade. A method of compensating power delivered to the ultrasonic device may include determining an articulation angle of an articulatable ultrasonic blade coupled to the ultrasonic transducer, adjusting a complex impedance of the ultrasonic transducer to compensate for power lost as a function of the articulation angle, and adjusting, a power applied to the ultrasonic transducer based on the articulation angle. The ultrasonic device may include a generator and a control circuit configured to effect the method.