Vessel sensing for adaptive advanced hemostasis
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.
1. A method of delivering energy to an ultrasonic device, the ultrasonic device comprising an electromechanical ultrasonic system defined by a predetermined resonant frequency, the electromechanical ultrasonic system further comprising an ultrasonic transducer coupled to an ultrasonic blade, the method comprising:
measuring, by a control circuit, a complex impedance of the ultrasonic transducer at a frequency f, wherein the complex impedance is defined as
Z
g
(
t
)
=
V
g
(
t
)
I
g
(
t
)
;
receiving, by the control circuit, a complex impedance measurement data point comprising an impedance magnitude |Z|, an impedance phase φ, and the frequency f;
calculating, by the control circuit, a Euclidean distance between the complex impedence measurement data point and a data point in a reference complex impedance characteristic pattern;
classifying, by the control circuit, the complex impedance measurement data point based on the Euclidean distance;
assigning, by the control circuit, a vessel type in contact with the ultrasonic blade coupled to the ultrasonic transducer based on the Euclidean distance, wherein
the vessel type is either a vein or an artery;
delivering, by the control circuit, power to the ultrasonic transducer based on the vessel type; and
applying power, by the control circuit, to the ultrasonic transducer at a power level P for a period T based on the assigned vessel type, wherein the power level P is different from a nominal power level Pn and the period T is different from a nominal period Tn,
thereby sealing and cutting a vessel having the vessel type.
2. The method of claim 1 , wherein applying power to the ultrasonic transducer at a power level P for a period T comprises applying power to the ultrasonic transducer at a power level P that is lower than the nominal power level Pn for a period T that is longer than the nominal period Tn when the assigned vessel type is a vein.
3. The method of claim 1 , wherein applying power to the ultrasonic transducer at a power level P for a period T comprises applying power to the ultrasonic transducer at a power level P that is greater than the nominal power level Pn for a period T that is shorter than the nominal period Tn when the assigned vessel type is an artery.
4. A method of applying energy to an ultrasonic device, the ultrasonic device comprising an electromechanical ultrasonic system defined by a predetermined resonant frequency, the electromechanical ultrasonic system comprising an ultrasonic transducer coupled to an ultrasonic blade, the method comprising:
measuring, by a control circuit, a complex impedance of the ultrasonic transducer at a frequency f, wherein the complex impedance is defined as
Z
g
(
t
)
=
V
g
(
t
)
I
g
(
t
)
;
receiving, by the control circuit, a complex impedance measurement data point comprising an impedance magnitude |Z|, an impedance phase φ, and the frequency f;
calculating, by the control circuit, a Euclidean distance between the complex impedance measurement data point and a data point in a reference complex impedance characteristic pattern;
classifying, by the control circuit, the complex impedance measurement data point based on the Euclidean distance;
assigning, by the control circuit, a vessel type in contact with the ultrasonic blade coupled to the ultrasonic transducer based on the Euclidean distance, wherein
the vessel type is either a vein or an artery; and
applying, by the control circuit, power to the ultrasonic transducer at a power level P for a period T based on the assigned vessel type, wherein the power level P is different from a nominal power level Pn and the period T is different from a nominal period Tn based on the vessel type,
thereby sealing and cutting a vessel having the vessel type.
5. The method of claim 4 , further comprising:
applying, by the control circuit, a power level to achieve a targeted ultrasonic blade temperature for a vein when the assigned vessel type is a vein; and
receiving a feedback control, by the control circuit, to maintain the targeted ultrasonic blade temperature for the vein.
6. The method of claim 4 , comprising:
applying, by the control circuit, a power level to achieve a targeted ultrasonic blade temperature for an artery when the assigned vessel type is an artery; and
receiving a feedback control, by the control circuit, to maintain the targeted ultrasonic blade temperature for the artery.
7. 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,
wherein the generator comprises a control circuit configured to:
measure a complex impedance of the ultrasonic transducer at a frequency f, wherein the complex impedance is defined as
Z
g
(
t
)
=
V
g
(
t
)
I
g
(
t
)
;
receive a complex impedance measurement data point comprising an impedance magnitude |Z|, an impedance phase φ, and the frequency f;
calculate a Euclidean distance between the complex impedance measurement data point and a data point in a reference complex impedance characteristic pattern;
classify the complex impedance measurement data point based on the Euclidean distance;
assign a vessel type in contact with the ultrasonic blade coupled to the ultrasonic transducer based on the Euclidean distance, wherein
the vessel type is either a vein or an artery;
deliver power to the ultrasonic transducer based on the vessel type; and
apply power to the ultrasonic transducer at a power level P for a period T based on the assigned vessel type, wherein the power level P is different from a nominal power level Pn and the period T is different from a nominal period Tn, to thereby seal and cut a vessel having the vessel type.
8. The ultrasonic surgical instrument of claim 7 , wherein the power level P is lower than the nominal power level Pn for a period T that is longer than the nominal period Tn when the assigned vessel type is a vein.
9. The ultrasonic surgical instrument of claim 7 , wherein the power level P that is greater than the nominal power level Pn for a period T that is shorter than the nominal period Tn when the assigned vessel type is an artery.
10. 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,
wherein the generator comprises a control circuit configured to:
measure a complex impedance of the ultrasonic transducer at a frequency f, wherein the complex impedance is defined as
Z
g
(
t
)
=
V
g
(
t
)
I
g
(
t
)
;
receive a complex impedance measurement data point comprising an impedance magnitude |Z|, an impedance phase φ, and the frequency f;
calculate a Euclidean distance between the complex impedance measurement data point and a data point in a reference complex impedance characteristic pattern;
classify the complex impedance measurement data point based on the Euclidean distance;
assign a vessel type in contact with the ultrasonic blade coupled to the ultrasonic transducer based on the Euclidean distance, wherein
the vessel type is either a vein or an artery; and
apply power to the ultrasonic transducer at a power level P for a period T based on the assigned vessel type, wherein the power level P is different from a nominal power level Pn and the period T is different from a nominal period Tn based on the vessel type to thereby seal and cut a vessel having the vessel type.
11. The ultrasonic surgical instrument of claim 10 , wherein the generator comprises a control circuit further configured to:
apply a power level to achieve a targeted ultrasonic blade temperature for a vein when the assigned vessel type is a vein; and
receive a feedback control to maintain the targeted ultrasonic blade temperature for the vein.
12. The ultrasonic surgical instrument of claim 10 , wherein the generator comprises a control circuit further configured to:
apply a power level to achieve a targeted ultrasonic blade temperature for an artery when the assigned vessel type is an artery; and
receive a feedback control to maintain the targeted ultrasonic blade temperature for the artery.