Estimating state of ultrasonic end effector and control system therefor
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.
1. A surgical system comprising:
an ultrasonic device comprising a jaw clamp and an electromechanical ultrasonic system defined by a predetermined resonant frequency,
wherein the electromechanical ultrasonic system comprises an ultrasonic transducer coupled to an ultrasonic blade via an ultrasonic waveguide;
a surgical hub system comprising a communication circuit, wherein the surgical hub system is in communication with the ultrasonic device;
a generator configured to supply power to the ultrasonic transducer, wherein the generator comprises a control circuit to:
cause a drive circuit to apply a drive signal to the ultrasonic transducer, wherein the drive signal is defined by a magnitude and a frequency;
sweep the frequency of the drive signal from below the predetermined resonant frequency to above the predetermined resonant frequency;
measure and record impedance circle variables R e and X e , and admittance circle variables G e and B e ;
compare the measured impedance circle variables R e and X e and the measured admittance circle variables Ge and Be to reference impedance circle variables R ref and X ref , and reference admittance circle variables G ref and B ref , respectively; and
determine a state or condition of an end effector of the ultrasonic device based on the result of the comparison.
2. The surgical system of claim 1 , wherein the reference impedance circle variables R ref and X ref , and the reference admittance circle variables G ref and B ref are stored in a database of the ultrasonic device.
3. The surgical system of claim 1 , wherein the reference impedance circle variables R ref and X ref , and the reference admittance circle variables G ref and B ref correspond to an open and unloaded jaw clamp.
4. The surgical system of claim 1 , wherein the reference impedance circle variables R ref and X ref , and the reference admittance circle variables G ref and B ref correspond to the jaw clamp fully clamped on a moist chamois.
5. The surgical system of claim 1 , wherein the reference impedance circle variables R ref and X ref , and the reference admittance circle variables G ref and B ref are accessible to the surgical hub system from a cloud-based memory storage unit.
6. The surgical system of claim 1 , wherein the drive signal is a periodic signal.
7. The surgical system of claim 1 , wherein the control circuit is further configured to:
plot real resistance values R e and imaginary impedance values X e on a two-dimensional graph; and
fit the real resistance values R e and the imaginary impedance values X e to a circle having a radius and offset values.
8. The surgical system of claim 1 , wherein the control circuit is further configured to:
plot real conductance values G e and imaginary susceptance values B e on a second two-dimensional graph; and
fit the real conductance values G e and the imaginary susceptance values B e to a second circle having a second radius and second offset values.
9. The surgical system of claim 1 , wherein the generator is disposed within a generator module of the surgical hub system.
10. A surgical system comprising:
a smart surgical device;
a surgical hub system comprising a communication circuit, wherein the surgical hub system is in communication with the smart surgical device;
a generator configured to supply power to the smart surgical device, wherein the generator comprises a control circuit to:
cause a drive circuit to apply a drive signal to the smart surgical device, wherein the drive signal is defined by a magnitude and a frequency;
sweep the frequency of the drive signal from below a predetermined resonant frequency of the smart surgical device to above the predetermined resonant frequency;
measure and record impedance circle variables R e and X e , and admittance circle variables G e and B e ;
compare the measured impedance circle variables R e and X e and the measured admittance circle variables G e and B e to reference impedance circle variables R ref and X ref , and reference admittance circle variables G ref and B ref , respectively; and
determine a state or condition of an end effector of the smart surgical device based on the result of the comparison.
11. The surgical system of claim 10 , wherein the reference impedance circle variables R ref and X ref , and the reference admittance circle variables G ref and B ref are stored in a database of the ultrasonic smart surgical device instrument.
12. The surgical system of claim 10 , wherein the reference impedance circle variables R ref and X ref , and the reference admittance circle variables G ref and B ref are accessible to the surgical hub system from a cloud-based memory storage unit.
13. The surgical system of claim 10 , wherein the drive signal is a periodic signal.
14. The surgical system of claim 10 , wherein the control circuit is further configured to:
plot real resistance values R e and imaginary impedance values X e on a two-dimensional graph; and
fit the real resistance values R e and the imaginary impedance values X e to a circle having a radius and offset values.
15. The surgical system of claim 10 , wherein the control circuit is further configured to:
plot real conductance values G e and imaginary susceptance values B e on a second two-dimensional graph; and
fit the real conductance values G e and the imaginary susceptance values B e to a second circle having a second radius and second offset values.
16. The surgical system of claim 10 , wherein the generator is disposed within a generator module of the surgical hub system.
17. A method of controlling a surgical system comprising:
applying, by a control circuit, a drive signal to an ultrasonic transducer of an electromechanical ultrasonic system, wherein the drive signal is defined by a magnitude and a frequency;
sweeping, by the control circuit, the frequency of the drive signal from below a predetermined resonant frequency of the electromechanical ultrasonic system to above the predetermined resonant frequency of the electromechanical ultrasonic system;
measuring and recording, by the control circuit, impedance circle variables R e and X e , and admittance circle variables G e and B e ;
obtaining, by a surgical hub system comprising a communication circuit, reference impedance circle variables R ref and X ref , and reference admittance circle variables G ref and B ref , from a cloud-based memory storage unit;
comparing, by the control circuit, the measured impedance circle variables R e and X e and the measured admittance circle variables G e and B e to the reference impedance circle variables R ref and X ref , and the reference admittance circle variables G ref and B ref , respectively; and
determining, by the control circuit, a state or condition of an end effector of the electromechanical ultrasonic system based on the result of the comparison.
18. The method of controlling the surgical system of claim 17 , further comprising:
plotting, by the control circuit, real resistance values R e and imaginary impedance values X e on a two-dimensional graph; and
fitting, by the control circuit, the real resistance values R e and the imaginary impedance values X e to a circle having a radius and offset values.
19. The method of controlling the surgical system of claim 17 , further comprising:
plotting, by the control circuit, real conductance values G e and imaginary susceptance values B e on a second two-dimensional graph; and
fitting, by the control circuit, the real conductance values G e and the imaginary susceptance values B e to a second circle having a second radius and second offset values.