A method of delivering energy to a surgical instrument of a surgical system having an ultrasonic blade and an RF electrode, the surgical system including (a) the surgical instrument, comprising:
- (i) a body, (ii) a shaft extending distally from the body, (iii) the ultrasonic transducer supported by the body, and (iv) an end effector arranged at a distal end of the shaft, wherein the end effector comprises:
- (A) an ultrasonic blade, wherein the ultrasonic transducer is operable to drive the ultrasonic blade with ultrasonic energy, and (B) the RF electrode operable to seal tissue with RF energy;
- (b) a generator operatively coupled with the surgical instrument, wherein the generator is operable to generate a combined drive signal having an ultrasonic energy component and an RF energy component;
- (c) an accessory device configured to operatively couple the surgical instrument and the generator, and (d) a signal filter arranged externally of the body of the surgical instrument, wherein the signal filter includes an ultrasonic output and an RF output and is operable to convert the combined drive signal to:
- (i) an ultrasonic drive signal configured to energize the ultrasonic transducer to drive the ultrasonic blade with ultrasonic energy, wherein the ultrasonic output of the signal filter is configured to electrically connect to the ultrasonic transducer via the accessory device for communicating the ultrasonic drive signal from the ultrasonic output of the signal filter to the ultrasonic transducer, and (ii) an RF drive signal configured to energize the RF electrode with RF energy sufficient to seal tissue, wherein the RF output of the signal filter is configured to electrically connect to the RF electrode via the accessory device for communicating the RF drive signal from the RF output of the signal filter to the RF electrode, wherein at least a portion of the accessory device is configured to communicate each of the separated ultrasonic and RF electrode drive signals externally therefrom and respectively to the ultrasonic transducer and the RF electrode, the method comprising:
- (a) generating the combined drive signal with the generator, wherein the combined drive signal includes the ultrasonic energy component and the RF energy component;
- (b) receiving the combined drive signal with the accessory device that communicates with the generator and with the surgical instrument, wherein the accessory device includes signal filter;
- (c) filtering the combined drive signal with the signal filter to produce the ultrasonic drive signal and the separate RF drive signal;
- (d) transmitting, simultaneously, the ultrasonic drive signal and the RF drive signal from the accessory device to the surgical instrument so that:
- (i) the ultrasonic drive signal energizes the ultrasonic transducer to drive the ultrasonic blade with ultrasonic energy, and
- (ii) the RF drive signal energizes the RF electrode with RF energy sufficient to seal tissue.