An ultrasonic device may include an electromechanical ultrasonic system defined by a predetermined resonant frequency, the electromechanical ultrasonic system further including an ultrasonic transducer coupled to an ultrasonic blade. A method of delivering energy to the ultrasonic device may include measuring a complex impedance of the ultrasonic blade coupled to the ultrasonic transducer, comparing the measured complex impedance to stored values of complex impedance patterns associated with ultrasonic blade functions, and applying, an algorithm to control a power output to the ultrasonic transducer based on the comparison. The method may further include delivering energy to the ultrasonic device based on a state or condition of an end effector, in which the state or condition of the end effector corresponds to a state of only sealing a tissue or of spot coagulating the tissue.

A generator, ultrasonic device, and method for controlling 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. The control circuit controls the temperature of the ultrasonic blade based on the inferred temperature

Various aspects of a generator, ultrasonic device, and method for estimating and controlling 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 $Z_g\left(t\right)=\frac{V_g\left(t\right)}{I_g\left(t\right)}.$
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. The control circuit estimates the state of the end effector of the ultrasonic device and controls the state of the end effector of the ultrasonic device based on the estimated state.

A generator, ultrasonic device, and method for controlling 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. The control circuit controls the temperature of the ultrasonic blade based on the inferred temperature

A surgical procedure of preparing bone holes to dispose an implanted tendon to a femur when performing reconstruction of a ligament in a knee joint, includes: forming a first bone hole in the femur; and applying ultrasonic vibration from a treatment portion of an ultrasonic treatment instrument to the femur, thereby cutting and expanding the first bone hole from the inside of the knee joint to the first bone hole of the femur along a predetermined depth, and forming a second bone hole having a polygonal shape, an approximately polygonal shape, an elliptical shape or an approximately elliptical shape to receive the implanted tendon.

An ultrasonic vibration transmittable probe includes a probe body configured to transmit ultrasonic vibration generated by an ultrasonic transducer. A treatment section is provided on a distal end side of the probe body along its longitudinal axis and is configured to cut a treatment object with the ultrasonic vibration. The treatment section includes first to third cutting surfaces disposed at progressively proximal positions. A portion of the first cutting surface has a dimension along a first orthogonal direction orthogonal to the longitudinal axis that is smaller than a dimension of the second cutting surface along the first orthogonal direction.

Surgical instruments and system and methods for using surgical instruments are disclosed. A surgical instrument comprises an end effector comprising an ultrasonic blade and clamp arm, an ultrasonic transducer, and a control circuit. The ultrasonic transducer ultrasonically oscillates the ultrasonic blade in response to a drive signal from a generator. The end effector receives electrosurgical energy to weld tissue. The control circuit determines a resonant frequency measure indicative of a thermally induced change in resonant frequency and a electrical continuity measure; calculates a weld focal point based on the determined measures, controls closure of the clamp arm to vary a pressure applied by the clamp arm to provide a threshold control pressure to the tissue loaded into the end effector, and maintains a gap between the ultrasonic blade and clamp arm at a point proximal to the proximal end of the tissue. Pressure is varied based on corresponding weld focal point.

A method of controlling the temperature of an ultrasonic blade between two temperature set points includes applying a first power level to an ultrasonic transducer to set an ultrasonic blade temperature to a first target temperature T1, monitoring a phase angle φ between voltage V.sub.g(t) and current I.sub.g(t) signals applied to the transducer, inferring the temperature of the blade based on the phase angle φ, determining that a transection process is complete, and applying a second power level to the transducer to set the blade temperature to a second target temperature T2. The transducer may be coupled to the blade via an ultrasonic waveguide. The first target temperature may be optimized for vessel sealing and the second target temperature may be optimized for clamp arm pad life. The control circuit may determine that transection is complete by determining that the ultrasonic blade contacts the clamp arm pad.

An ultrasonic device may include an electromechanical ultrasonic system having a resonant frequency, the system including a transducer coupled to an ultrasonic blade. A method of driving the blade may include determining a tissue type contacting the blade, setting current delivered to the transducer to achieve a desired blade temperature, and setting a desired period during which the desired temperature is applied to the tissue. The tissue type may be determined by measuring an impedance of the transducer, comparing an impedance measurement data point to a reference data point, and classifying the impedance measurement data point based on a result of the comparison. Alternatively, the tissue type may be determined by applying a drive signal to the transducer, sweeping the frequency of the drive signal from below to above a resonance of the ultrasonic system, measuring and recording impedance/admittance variables, and comparing the measured variables to reference variables.

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.