Devices and techniques for cutting and coagulating tissue
AssigneeEthicon Endo-Surgery, Inc.
InventorsJeffrey D. Messerly, Eitan T. Wiener, Brian T. Noyes, Jeffrey L. Aldridge, James R. Giordano, Robert J. Beetel, Daniel J. Abbott, Foster B. Stulen, Matthew C. Miller, Nathan J. Price, Daniel W. Price
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Abstract
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.
Claims21
A method of driving an ultrasonic transducer of a surgical instrument, the method comprising:
- generating by a generator coupled to an ultrasonic transducer at least one time varying electrical signal at a resonant frequency of the ultrasonic transducer;
- sampling the frequency of the at least one time varying electrical signal over a predetermined time period to obtain at least two sampled frequency data points of the at least one time varying signal;
- calculating a frequency slope between the at least two sampled frequency data points of the at least one time varying electrical signal over the predetermined time period, where the frequency slope is the difference between the at least two sampled frequency data points over the predetermined time period;
- comparing the frequency slope to a frequency slope threshold;
- and
- triggering a first response of the generator when the frequency slope crosses the frequency slope threshold.
An ultrasonic drive system for driving an ultrasonic transducer of a surgical instrument, the ultrasonic drive system comprising:
- a generator coupled to the ultrasonic transducer to generate at least one time varying electrical signal at a resonant frequency of the ultrasonic transducer;
- an analog-to-digital converter coupled to the generator to sample the frequency of the at least one time varying electrical signal over a predetermined time period to obtain at least two sampled frequency data points of the at least one time varying signal;
- and
- a processor coupled to the analog-to-digital converter, wherein the processor is operative to:
- calculate a frequency slope between the at least two sampled frequency data points of the at least one time varying electrical signal over a predetermined time period, where the frequency slope is the difference between the at least two sampled frequency data points over the predetermined time period;
- compare the frequency slope to a frequency slope threshold;
- and
- trigger a first response of the generator when the frequency slope crosses the frequency slope threshold.
The ultrasonic drive system of 19, wherein the moving average filter is operative to calculate the exponentially weighted moving average of the sampled voltage according to the following formula:
- S′tv=α′Y′tv+(1−α′)S′tv-1
- where:
- S′tv is the current moving average of the sampled voltage;
- S′tv-1 is the previous moving average of the sampled voltage;
- α′ is the smoothing factor;
- and
- Y′tv is current data point of the sampled voltage.
A surgical instrument, comprising:
- an ultrasonic transducer;
- an end effector coupled to the ultrasonic transducer;
- and
- an ultrasonic drive system coupled to the ultrasonic transducer, the ultrasonic drive system comprising:
- a generator coupled to the end effector to generate at least one time varying electrical signal at a resonant frequency of the ultrasonic transducer;
- an analog-to-digital converter coupled to the generator to sample the frequency of the at least one time varying electrical signal over a predetermined time period to obtain at least two sampled frequency data points of the at least one time varying signal;
- and
- a processor coupled to the analog-to-digital converter, wherein the processor is operative to:
- calculate a frequency slope between the at least two sampled frequency data points of the at least one time varying electrical signal over a predetermined time period, where the frequency slope is the difference between the at least two sampled frequency data points over the predetermined time period;
- compare the frequency slope to a frequency slope threshold;
- and
- trigger a first response of the generator when the frequency slope crosses the frequency slope threshold.
Dependencies are inferred from the claim text.