Modular battery powered handheld surgical instrument with motor control limits based on tissue characterization

A method for operating a surgical instrument, the surgical instrument comprising a shaft assembly comprising a shaft and an end effector coupled to a distal end of the shaft, and a handle assembly coupled to a proximal end of the shaft, the method comprising:

• actuating a driver using an output of a battery-powered motor;
• driving, with the driver, movement of a first component of the surgical instrument;
• determining, based at least in part on a tissue characteristic, a first limiting condition and a second limiting condition, where the first limiting condition provides a higher limiting threshold than the second limiting condition;
• performing a first limiting operation to the output of the motor by decreasing the output of the motor when the output reaches the first limiting condition, wherein the first limiting operation controls the movement of the first component;
• performing a second limiting operation to the output of the motor by increasing the output of the motor when the output falls below the second limiting condition, wherein the second limiting operation controls the movement of the first component;
• determining a third limiting condition;
• and
• performing a third limiting operation to the output of the motor, wherein the third limiting operation controls movement of a second component of the surgical instrument;
• wherein the motor is configured to control movement of both the first component and the second component.

A surgical instrument, comprising:

• a shaft assembly comprising a shaft and an end effector coupled to a distal end of the shaft;
• a handle assembly coupled to a proximal end of the shaft;
• a battery assembly coupled to the handle assembly;
• at least one component comprising a transducer configured to output ultrasonic energy;
• a driver coupled to the transducer and configured to drive movement of the transducer;
• a motor powered by the battery assembly and configured to actuate the driver using an output of the motor;
• and
• a controller for the motor, configured to:
• provide a tactile feedback felt by a user through physical movement initiated by the surgical instrument to indicate an error has occurred, the error comprising the transducer having a mismatched frequency with the driver.