Devices and techniques for cutting and coagulating tissue
View Patent ↗Various embodiments are directed to a method of driving an end effector coupled to an ultrasonic drive system of a surgical instrument. The method comprises generating at least one electrical signal. The at least one electrical signal is monitored against a first set of logic conditions. A first response is triggered when the first set of logic conditions is met. A parameter is determined from the at least one electrical signal.
1. A method of driving an end effector coupled to an ultrasonic drive system of a surgical instrument, the method comprising:
generating, by a generator, at least one electrical signal;
monitoring the at least one electrical signal against a first set of logic conditions;
triggering a first response of the generator when the first set of logic conditions is met;
determining, from the at least one electrical signal, a parameter associated with the surgical instrument, the determined parameter being a rate of temperature change of the end effector assessed by calculating a frequency slope; and
comparing the frequency slope against a predetermined threshold.
2. The method of claim 1 , wherein the rate of temperature change is a rate of cooling.
3. The method of claim 1 , wherein the rate of temperature change is a rate of heating.
4. A method of driving an end effector coupled to an ultrasonic drive system of a surgical instrument, the method comprising:
generating, by a generator, at least one electrical signal;
monitoring the at least one electrical signal against a first set of logic conditions;
triggering a first response of the generator when the first set of logic conditions is met; and
determining, from the at least one electrical signal, a parameter associated with the surgical instrument, wherein the determined parameter is proportional to a frequency slope, and wherein the determined parameter is a rate of temperature change of the end effector.
5. The method of claim 4 , wherein the rate of temperature change is a rate of cooling.
6. The method of claim 4 , wherein the rate of temperature change is a rate of heating.
7. A device for driving an end effector coupled to an ultrasonic drive system of a surgical instrument, the device comprising:
a generator configured to generate at least one electrical signal; and
a control circuit, comprising:
a processor; and
a memory storing program instructions, which, when executed by the processor, cause the processor to perform the steps of:
monitoring the at least one electrical signal against a first set of logic conditions;
triggering a first response of the generator when the first set of logic conditions is met;
determining, from the at least one electrical signal, a parameter associated with the surgical instrument, wherein the determined parameter is a rate of temperature change of the end effector assessed by calculating a frequency slope, and
comparing the frequency slope against a predetermined threshold.
8. The device of claim 7 , wherein the rate of temperature change is a rate of cooling.
9. The device of claim 7 , wherein the rate of temperature change is a rate of heating.
10. A device for driving an end effector coupled to an ultrasonic drive system of a surgical instrument, the device comprising:
a generator configured to generate at least one electrical signal; and
a control circuit, comprising:
a processor; and
a memory storing program instructions, which, when executed by the processor, cause the processor to perform the steps of:
monitoring the at least one electrical signal against a first set of logic conditions;
triggering a first response of the generator when the first set of logic conditions is met; and
determining, from the at least one electrical signal, a parameter associated with the surgical instrument; and
wherein the determined parameter is proportional to a frequency slope, and wherein the determined parameter is a rate of temperature change of the end effector.
11. The device of claim 10 , wherein the rate of temperature change is a rate of cooling.
12. The device of claim 10 , wherein the rate of temperature change is a rate of heating.
13. A device for driving an end effector coupled to an ultrasonic drive system of a surgical instrument, the device comprising:
a generator configured to generate at least one electrical signal; and
a control circuit, comprising:
a processor; and
memory-storing program instructions, which, when executed by the processor, cause the processor to perform the steps of:
monitoring the at least one electrical signal against a first set of logic conditions;
triggering a first response of the generator when the first set of logic conditions is met;
determining, from the at least one electrical signal, a parameter associated with the surgical instrument; and
monitoring impedance of a transducer of the ultrasonic drive system in a dwells region during pulsed activation.
14. The device of claim 13 , wherein the determined parameter is an impedance of the end effector, and wherein the steps further comprise:
resetting the generator when the impedance crosses a predetermined threshold.