Electrosurgical instrument and method of monitoring clamp position to adjust energy application

A surgical instrument, comprising:

• (a) an end effector, including:
• (i) a first jaw having a first electrode, and
• (ii) a second jaw having a second electrode and configured to selectively move relative to the first jaw from an open configuration configured to receive a tissue toward a closed configuration to compress the tissue therebetween, wherein the first and second electrodes are configured to apply a radiofrequency (RF) energy through the tissue with the first and second jaws in the closed configuration;
• and
• (b) a controller operatively connected to the first and second jaws and configured to:
• (i) activate a power of the RF energy according to a predetermined power,
• (ii) detect a first jaw gap between the first and second jaws in the closed configuration with tissue received therebetween and the power of the RF energy activated,
• (iii) after detecting the first jaw gap, detect a second jaw gap between the first and second jaws in the closed configuration with tissue received therebetween and the power of the RF energy activated,
• (iv) determine a jaw gap contraction rate based on the first and second jaw gaps,
• (v) compare the jaw gap contraction rate to at least one predetermined contraction rate threshold, and
• (iv) adjust the power of the RF energy while applying the RF energy to the tissue in response to the jaw gap contraction rate reaching the predetermined contraction rate threshold.

A method of adjusting a power of a radiofrequency (RF) energy applied to a tissue via a surgical instrument, the surgical instrument including:

• (a) an end effector, including:
• (i) a first jaw having a first electrode, and (ii) a second jaw having a second electrode and configured to selectively move relative to the first jaw from an open configuration configured to receive a tissue toward a closed configuration to compress the tissue therebetween, wherein the first and second electrodes are configured to apply the RF energy through the tissue with the first and second jaws in the closed configuration;
• and (b) a controller operatively connected to the first and second jaws, the method comprising:
• (a) determine an impedance of the tissue while applying the RF energy to the tissue;
• (b) determining a jaw gap contraction rate while applying the RF energy to the tissue, wherein the jaw gap contraction rate is based on a rate of change of a gap between the first jaw and the second jaw;
• (c) comparing the jaw gap contraction rate to at least one predetermined contraction rate threshold;
• and
• (d) adjust a power of the RF energy while applying the RF energy to the tissue in response to the jaw gap contraction rate reaching the predetermined contraction rate threshold.