Patent attributes
A surgical stapling system is disclosed comprising an end effector configurable in an open configuration and a clamped configuration. The end effector comprises a firing member that moves toward an ending position in response to a firing motion. A sensor is configured to produce a signal corresponding to the configuration of the end effector. A rotatable drive screw is drivable by an electric motor and is threadably engaged with the firing member such that rotary motion is converted to the firing motion. A control system is configured to evaluate the signal produced by the sensor and allows the electric motor to provide the firing motion to the firing member if the end effector is in the clamped configuration. The control system does not allow the electric motor to provide the firing motion to the firing member if the end effector is in the open configuration.