Devices and techniques for cutting and coagulating tissue
View Patent ↗Various embodiments are directed to an apparatus and 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.
1. A method of driving an ultrasonic end effector coupled to an ultrasonic drive system of a surgical instrument, the method comprising:
generating by a generator at least one time varying electrical signal to drive the ultrasonic end effector at a resonant frequency thereof;
monitoring the resonant frequency of the ultrasonic end effector;
comparing the resonant frequency to a threshold frequency;
triggering a first response of the generator when the resonant frequency crosses the threshold frequency;
incrementing a timer when the resonant frequency is less than the threshold frequency; and
setting a logic condition when the timer is greater than a required trigger time.
2. The method of claim 1 , comprising:
determining when the resonant frequency is less than the threshold frequency; and
determining when the timer is greater than the required trigger time.
3. The method of claim 1 , comprising:
resetting the timer when the resonant frequency is greater than the threshold frequency;
comparing a latched time with a minimum latch time; and
resetting the timer when the latched time is greater than the minimum latch time.
4. The method of claim 1 , further comprising generating an audible feedback when the first response is triggered.
5. The method of claim 1 , further comprising generating a visual feedback when the first response is triggered.
6. The method of claim 1 , further comprising generating a tactile feedback when the first response is triggered.
7. A surgical instrument, comprising:
an ultrasonic drive system;
an ultrasonic end effector coupled to the ultrasonic drive system;
a generator coupled to the ultrasonic drive system, the generator comprising a processor operative to generate at least one time varying electrical signal to drive the ultrasonic end effector at a resonant frequency thereof; and
a circuit coupled to the generator to monitor the resonant frequency of the ultrasonic end effector, wherein the circuit is operable to:
compare the resonant frequency to a threshold frequency and trigger a first response of the generator when the resonant frequency crosses the threshold frequency;
increment a timer when the resonant frequency is less than the threshold frequency; and
set a logic condition when the timer is greater than a required trigger time.
8. The surgical instrument of claim 7 , wherein the processor is operative to:
determine when the resonant frequency is less than the threshold frequency; and
determine when the timer is greater than the required trigger time.
9. The surgical instrument of claim 7 , wherein the processor is operative to:
reset the timer when the resonant frequency is greater than the threshold frequency;
compare a latched time with a minimum latch time; and
reset the timer when the latched time is greater than the minimum latch time.
10. The surgical instrument of claim 7 , comprising a speaker coupled to and responsive to the circuit.
11. The surgical instrument of claim 7 , comprising a display coupled to and responsive to the circuit.
12. The surgical instrument of claim 7 , comprising a haptic device coupled to and responsive to the circuit.
13. A surgical instrument, comprising:
an ultrasonic drive system;
an ultrasonic end effector coupled to the ultrasonic drive system;
a generator coupled to the ultrasonic drive system, the generator comprising a processor operative to generate at least one time varying electrical signal to drive the ultrasonic end effector at a resonant frequency thereof;
a circuit coupled to the generator to monitor the resonant frequency of the ultrasonic end effector, wherein the circuit is operable to:
compare the resonant frequency to a threshold frequency and trigger a first response of the generator when the resonant frequency crosses the threshold frequency; and
a pulsing circuit coupled to and responsive to the circuit, wherein the pulsing circuit is operative to:
generate a first pulse amplitude for a first period over which the generator is driven; and
generate a second pulse amplitude for a second period over which the generator is driven.
14. The surgical instrument of claim 13 , wherein the processor is operative to:
increment a timer when the resonant frequency is less than the threshold frequency; and
set a logic condition when the timer is greater than the required trigger time.
15. The surgical instrument of claim 13 , wherein the processor is operative to:
determine when the resonant frequency is less than the threshold frequency; and
determine when a timer is greater than a required trigger time.
16. The surgical instrument of claim 13 , wherein the processor is operative to:
reset a timer when the resonant frequency is greater than the threshold frequency;
compare a latched time with a minimum latch time; and
reset the timer when the latched time is greater than the minimum latch time.
17. The surgical instrument of claim 13 , comprising a speaker coupled to and responsive to the circuit.
18. The surgical instrument of claim 13 , comprising a display coupled to and responsive to the circuit.
19. The surgical instrument of claim 13 , comprising a haptic device coupled to and responsive to the circuit.