Closed loop control of motor velocity of a surgical stapler

Abstract

A surgical stapler is presented which includes an end effector, a firing drive electric motor, and a control circuit. The motor is configured to translate a firing bar to deploy staples from the end effector during a staple firing stroke. The control circuit is configured to provide a pulse width modulated (PWM) electrical signal to the firing drive electric motor, compare an actual velocity of the firing bar to a directed velocity, and adjust a duty cycle of the PWM electrical signal based at least in part on the comparison. The control circuit can adjust the duty cycle based on one or more of a short term error (S), cumulative error (C), change error (R), a number of overshoots (N) calculated based on the comparison of the actual velocity to the directed velocity.

Dependencies are inferred from the claim text.