Using spectroscopy to determine device use state in combo instrument
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.
1. An ultrasonic surgical instrument comprising:
an ultrasonic electromechanical system comprising an ultrasonic transducer coupled to an ultrasonic blade via an ultrasonic waveguide; and
a generator configured to supply power to the ultrasonic transducer and further configured to supply power to a radio frequency (RF) electrosurgical instrument, wherein the generator comprises a control circuit configured to:
measure a complex impedance of the ultrasonic blade coupled to the ultrasonic transducer;
compare the measured complex impedance to stored values of complex impedance patterns associated with ultrasonic blade functions; and
apply an algorithm to control a power output to the ultrasonic transducer based on the comparison of the measured complex impedance to the stored values of complex impedance patterns associated with ultrasonic blade functions.
2. The ultrasonic surgical instrument of claim 1 , wherein the control circuit is further configured to deliver energy to the ultrasonic transducer based on a state or condition of an end effector, and wherein the control circuit is further configured to:
measure a complex impedance of the ultrasonic transducer, wherein the complex impedance of the ultrasonic transducer is defined as
Z
g
(
t
)
=
V
g
(
t
)
I
g
(
t
)
;
receive a complex impedance measurement data point;
compare the complex impedance measurement data point to a data point in a reference complex impedance characteristic pattern;
classify the complex impedance measurement data point based on a result of the comparison of the complex impedance measurement data point to the data point in the reference complex impedance characteristic pattern; and
assign the state or condition of the end effector based on the result of the comparison of the complex impedance measurement data point to the data point in the reference complex impedance characteristic pattern.
3. The ultrasonic surgical instrument of claim 2 , the state or condition of the end effector corresponds to a state of only sealing a tissue.
4. The ultrasonic surgical instrument of claim 2 , wherein the state or condition of the end effector corresponds to a state of spot coagulating a tissue.
5. The ultrasonic surgical instrument of claim 1 , wherein the control circuit is further configured to deliver energy to the ultrasonic transducer based on a state or condition of an end effector, wherein the control circuit is further configured to:
cause a drive circuit to apply a drive signal to the ultrasonic transducer, wherein the drive signal is a periodic signal defined by a magnitude and frequency;
sweep the frequency of the drive signal from below resonance to above resonance of the ultrasonic electromechanical system;
measure and record impedance/admittance circle variables R e , G e , X e , and B e ;
compare the measured impedance/admittance circle variables R e , G e , X e , and B e to reference impedance/admittance circle variables R ref , G ref , X ref , and B ret ; and
determine the state or condition of the end effector based on the comparison of the measured impedance/admittance circle variables R e , G e , X e , and B e to the reference impedance/admittance circle variables R ref , G ref , X ref , and B ref .
6. The ultrasonic surgical instrument of claim 5 , wherein the state or condition of the end effector corresponds to a state of only sealing a tissue.
7. The ultrasonic surgical instrument of claim 5 , wherein the state or condition of the end effector corresponds to a state of spot coagulating a tissue.
8. A generator for an ultrasonic surgical instrument, the generator comprising:
a control circuit configured to:
supply power to an ultrasonic transducer of the ultrasonic surgical instrument and supply power to a radio frequency (RF) electrosurgical instrument;
measure a complex impedance of an ultrasonic blade coupled to the ultrasonic transducer;
compare the measured complex impedance to stored values of complex impedance patterns associated with ultrasonic blade functions; and
apply an algorithm to control a power output to the ultrasonic transducer based on the comparison of the measured complex impedance to the stored values of complex impedance patterns associated with ultrasonic blade functions.
9. The generator of claim 8 , wherein the control circuit is further configured to deliver energy to the ultrasonic surgical instrument based on a state or condition of an end effector, wherein the control circuit is further configured to:
measure a complex impedance of the ultrasonic transducer, wherein the complex impedance of the ultrasonic transducer is defined as
Z
g
(
t
)
=
V
g
(
t
)
I
g
(
t
)
;
receive a complex impedance measurement data point;
compare the complex impedance measurement data point to a data point in a reference complex impedance characteristic pattern;
classify the complex impedance measurement data point based on the comparison of the complex impedance measurement data point to the data point in the reference complex impedance characteristic pattern; and
assign the state or condition of the end effector based on the comparison of the complex impedance measurement data point to the data point in the reference complex impedance characteristic pattern.
10. The generator of claim 9 , wherein the state or condition of the end effector corresponds to a state of only sealing a tissue.
11. The generator of claim 9 , wherein the state or condition of the end effector corresponds to a state of spot coagulating a tissue.
12. The generator of claim 8 , wherein the control circuit is further configured to deliver energy to the ultrasonic surgical instrument based on a state or condition of an end effector, wherein the control circuit is further configured to:
cause a drive circuit to apply a drive signal to the ultrasonic transducer, wherein the drive signal is a periodic signal defined by a magnitude and frequency;
sweep the frequency of the drive signal from below resonance to above resonance of the ultrasonic transducer;
measure and record impedance/admittance circle variables R e , G e , X e , and B e ;
compare the measured impedance/admittance circle variables R e , G e , X e , and B e to reference impedance/admittance circle variables R ref , G ref , X ref , and B ref ; and
determine the state or condition of the end effector based on the comparison of the measured impedance/admittance circle variables R e , G e , X e , and B e to the reference impedance/admittance circle variables R ref , G ref , X ref , and B ref .
13. The generator of claim 12 , wherein the state or condition of the end effector corresponds to a state of only sealing a tissue.
14. The generator of claim 12 , wherein the state or condition of the end effector corresponds to a state of spot coagulating a tissue.