Combination ultrasonic and electrosurgical instrument with clamp arm position input and method for identifying tissue state

An ultrasonic surgical instrument, comprising:

• (a) an end effector, including:
• (i) an ultrasonic blade configured to be selectively driven to apply ultrasonic energy to a tissue,
• (ii) a clamp arm configured to actuate relative to the ultrasonic blade from a first configuration toward a second configuration, wherein the clamp arm is configured to clamp the tissue against the ultrasonic blade in the second configuration, and
• (iii) an RF electrode positioned on the clamp arm and configured to be selectively driven to apply RF energy to the tissue, wherein the RF electrode is further configured to measure a tissue impedance of the tissue clamped against the ultrasonic blade;
• (b) a shaft assembly projecting proximally from the end effector;
• (c) a body projecting proximally from the shaft assembly, wherein the body includes:
• (i) a first ultrasonic energy input operatively connected to the ultrasonic blade, wherein the first ultrasonic energy input is configured to be selectively actuated from a first unactuated energy input state to a first actuated energy input state,
• (ii) a second ultrasonic energy input configured to be selectively actuated from a second unactuated energy input state to a second actuated energy input state, and
• (iii) a trigger input configured to be actuated from an unactuated trigger input state in the first configuration to an actuated trigger input state in the second configuration;
• and
• (d) a power controller operatively connected to the ultrasonic blade and the second ultrasonic energy input, the RF electrode, the first ultrasonic energy input, the second ultrasonic energy input, and the trigger input, wherein the power controller is configured to determine the measured tissue impedance as below a lower impedance threshold in a first electrical state of the ultrasonic blade and the RF electrode, above an upper impedance threshold in a second electrical state of the ultrasonic blade and the RF electrode, or intermediate between the lower and upper impedance thresholds in a third electrical state of the ultrasonic blade and the RF electrode, and wherein the power controller is further configured to direct activation of at least a portion of the end effector according to a predetermined drive function based on the state of the first ultrasonic energy input, the state of the second ultrasonic energy input, the state of the trigger input, and the identified tissue impedance being below the lower impedance threshold, above the upper impedance threshold, or intermediate between the lower and upper impedance thresholds,
• wherein the first electrical state is configured to indicate that the ultrasonic blade and the RF electrode are in direct electrical contact, wherein the second electrical state is configured to indicate that there is no direct electrical contact between the ultrasonic blade and the RF electrode and that there is no tissue in contact between the ultrasonic blade and the RF electrode, and wherein the third electrical state is configured to indicate that there is tissue in contact between the ultrasonic blade and the RF electrode, and
• wherein the power controller is further configured to initiate and direct activation of the at least the portion of the end effector according to the predetermined drive function based respectively on each of the first, second, and third electrical states such that the at least the portion of the end effector activates in each of the first, second, and third electrical states.

An ultrasonic surgical instrument, comprising:

• (a) an end effector configured to actuate from a first configuration to a second configuration, the end effector including:
• (i) an ultrasonic blade configured to be selectively driven to apply an ultrasonic energy to a tissue, and
• (ii) an RF electrode configured to be selectively driven to apply RF energy to the tissue, wherein the RF electrode is further configured to measure a tissue impedance of the tissue engaged by the end effector;
• (b) a shaft assembly projecting proximally from the end effector;
• (c) a body projecting proximally from the shaft assembly, wherein the body includes:
• (i) a first ultrasonic energy input operatively connected to the ultrasonic blade, wherein the first ultrasonic energy input is configured to be selectively actuated from a first unactuated energy input state to a first actuated energy input state,
• (ii) a trigger operatively connected to the end effector and configured to selectively actuate the end effector from the first configuration to the second configuration, and
• (iii) a trigger input operatively connected to the trigger, wherein the trigger input is configured to be actuated from an unactuated trigger input state in the first configuration to an actuated trigger input state in the second configuration;
• and
• (d) a power controller operatively connected to the ultrasonic blade, the RF electrode, the first ultrasonic energy input, and the trigger input, wherein the power controller is configured to direct activation of at least one of the ultrasonic blade or the RF electrode according to a predetermined drive function based on the tissue impedance, the state of the first energy input, and the state of the trigger input, and
• wherein the power controller includes a lower impedance threshold and an upper impedance threshold stored thereon, wherein the power controller is further configured to determine whether the measured tissue impedance is below the lower impedance threshold thereby correlating to a first electrical state, above the upper impedance threshold thereby correlating to a second electrical state, or intermediate between the lower and upper impedance thresholds thereby indicative of a third electrical state, and
• wherein the power controller is further configured to initiate and direct activation of the at least one of the ultrasonic blade or the RF electrode according to the predetermined drive function based on the identified tissue impedance being above the upper impedance threshold.