Surgical system with user adaptable techniques employing simultaneous energy modalities based on tissue parameters

A generator for delivering energy to a surgical instrument for coagulating and dissecting tissue, the surgical instrument comprising an end effector at a distal end thereof, the end effector configured to interact with tissue, the end effector comprising a clamp arm, an ultrasonic blade, an ultrasonic transducer acoustically coupled to the ultrasonic blade and configured to receive a drive signal from the generator to cause ultrasonic motion of the ultrasonic blade and deliver ultrasonic energy to the ultrasonic blade, the generator comprising:

• a first drive circuit configured to deliver a drive signal to an ultrasonic transducer;
• a second drive circuit configured to deliver radio frequency (RF) energy to the electrode;
• and
• a processor configured to control the first drive circuit and the second drive circuit, and wherein the processor is configured to:
• control the second drive circuit to deliver RF energy to the electrode and the first drive circuit to deliver ultrasonic energy to the ultrasonic blade based on a determination of tissue impedance of tissue engaged with the end effector;
• and
• control the first drive circuit and the second drive circuit to switch from delivery of RF energy to the electrode to delivery of ultrasonic energy to the ultrasonic blade when the tissue impedance matches a threshold impedance value.

A method of dissecting and coagulating tissue, comprising:

• calculating, by a processor, a tissue impedance of a tissue engaged with an end effector of a surgical instrument;
• comparing, by the processor, the calculated tissue impedance with a threshold impedance value;
• and
• delivering, by an RF drive circuit, RF energy to an electrode of the end effector when the calculated tissue impedance is less than the threshold impedance value;
• and
• delivering, by an ultrasonic drive circuit, ultrasonic energy to an ultrasonic blade of the end effector when the calculated tissue impedance is greater than or equal to the threshold impedance value.

A method of dissecting and coagulating tissue, comprising:

• delivering, by an RF drive circuit, RF energy to an electrode of a surgical instrument, wherein the surgical instrument is engaged with tissue, and wherein the electrode uses the RF energy to create a tissue seal during tissue coagulation of the tissue;
• calculating, by a processor, a tissue impedance of the tissue;
• comparing the calculated tissue impedance with a threshold impedance value;
• and
• delivering, by an ultrasonic drive circuit, ultrasonic energy to an ultrasonic blade of the surgical instrument when the calculated tissue impedance is greater than or equal to the threshold impedance value.