Multi-threshold motor control algorithm for powered surgical stapler

A surgical instrument comprising:

• (a) a shaft assembly extending distally;
• (b) an end effector operatively coupled with the shaft assembly, wherein the end effector comprises:
• (i) a first jaw including an anvil, and
• (ii) a second jaw including a stapling assembly having staples, wherein at least one of the first or second jaws is configured to pivot relative to the other of the first or second jaws between an open position and a closed position;
• (c) a driving assembly;
• (d) a motor configured to actuate the driving assembly to deploy the staples;
• (e) a sensor assembly configured to measure at least one of a firing force of the motor or a temperature of the motor as the motor actuates the driving assembly;
• and
• a motor controller in communication with the motor and configured to:
• (i) determine at least one of whether the measured firing force of the motor exceeds a first predetermined force threshold or whether the measured temperature of the motor exceeds a first predetermined temperature threshold in response to the stapling assembly interacting with tissue,
• (ii) reduce or stop power to the motor using a first power profile in response to determining that the measured firing force exceeds the first predetermined force threshold or the measured temperature exceeds the first predetermined temperature threshold,
• (iii) after reducing or stopping power to the motor, determine at least one of whether the measured firing force of the motor exceeds a second predetermined force threshold or whether the measured temperature of the motor exceeds a second predetermined temperature threshold in response to the stapling assembly interacting with tissue, wherein the second predetermined force threshold is greater than the first predetermined force threshold, wherein the second predetermined temperature threshold is greater than the first predetermined temperature threshold, and
• (iv) reduce or stop power to the motor using a second power profile that is different than the first power profile in response to determining that the measured firing force exceeds the second predetermined force threshold or the measured temperature exceeds the second predetermined temperature threshold.

A method of firing a robotically controlled end effector with a motor and a driving assembly to at least one of staple or cut tissue with the end effector, the method comprising:

• (a) distally advancing the driving assembly within the end effector;
• (b) detecting values of first and second trigger variables;
• (c) in response to detecting the values, determining whether the values exceed predetermined thresholds;
• and
• (d) in response to determining that the values of the first and second trigger variables exceed the predetermined thresholds, modifying at least one of:
• (i) a motion profile instituted by the motor controller for the motor,
• (ii) a waiting period during which power to the motor is reduced or stopped, or
• (iii) the predetermined threshold relating to current or force for proximal retraction of the driving assembly to be different from the predetermined threshold relating to current or force for distal advancement of the driving assembly.