Patent attributes
A robotic surgical system comprising a surgical robot, a surgical instrument, a motor, and a current sensor is disclosed. The surgical instrument comprises an end effector, a firing assembly, and a lockout mechanism. The firing assembly comprises a firing member movable from an unfired position to a fired position during a firing stroke and a sled movable from a proximal position to a distal position. The lockout mechanism is configured to prevent the firing stroke when the sled is not in the proximal position. The motor is operably coupled with the firing member and couplable with a supply of current. When the current through the motor exceeds a threshold value the firing member is prevented from completing the firing stroke. The threshold value corresponds to the current through the motor when the lockout mechanism is activated. The motor is de-energized when the current through the motor exceeds the threshold value.