US Patent 10238391 Drive train control arrangements for modular surgical instruments

A surgical instrument comprising an interchangeable shaft assembly is disclosed. The interchangeable shaft assembly comprises a shaft portion, an end effector configured to receive a staple cartridge including a plurality of staples, a firing assembly movable from a firing home state to deploy the plurality of staples from the staple cartridge, and an articulation assembly movable from an articulation home state to articulate the end effector relative to the shaft portion. The surgical instrument further comprises a housing detachable from the shaft portion, a circuit configured to transmit a home state input signal in response to an action performed to decouple the housing from the shaft portion, and a controller configured to cause the firing assembly to return to the firing home state and the articulation assembly to return to the articulation home state in response to the home state input signal.