A surgical stapling device includes an anvil assembly including an anvil shaft and an anvil head assembly that is supported on a distal end portion of the anvil shaft. The anvil shaft defines a longitudinal axis and supports a first spline, a second spline, and a third spline. Each of the first, second, and third splines includes a pair of tapered camming surfaces that meet at a proximal end of the respective spline to define an apex. The apex of the first spline is positioned on the anvil shaft at a location proximal of the apex of the second spline, and the apex of the second spline is positioned on the anvil shaft at a location proximal of the apex of the third spline. In embodiments, each of the splines includes an apex. The apex of the first spline is aligned with a longitudinal axis of the first spline and the apex of the second and third splines are aligned with a longitudinal axis of the second and third splines, respectively.

A surgical instrument system that includes a housing and a rotatable drive shaft, a motor operably coupled to the drive shaft, and a plurality of replaceable end effectors that can be connected to the housing. Each replaceable end effector includes a drive screw that is turned a fixed number of revolutions by the motor-driven rotatable drive shaft when the end effector is connected to the housing. Each end effector further comprises a firing member operably coupled with the drive screw of the end effector. The drive screw is configured to displace the firing member over a firing length as a result of the fixed number of revolutions. In certain embodiments, each replaceable end effector can include a drive screw with a thread pitch set to the firing length divided by the fixed number of revolutions.

A surgical instrument includes a body, an ultrasonic blade, a clamp arm, and a resilient member. The body includes an electrical conductor and defines a longitudinal axis. The clamp arm is pivotably coupled with the body at a pivot assembly. The clamp arm is operable to compress tissue against the ultrasonic blade. The clamp arm includes an electrode operable to apply RF energy to tissue, wherein the clamp arm is configured to be loaded onto and removed from the body at the pivot assembly along a path that is transverse to the longitudinal axis defined by the body. The resilient member is located within the pivot assembly. The resilient member is configured to provide electrical continuity between the electrode of the clamp arm and the electrical conductor of the body.

A surgical instrument comprising an adjustment system is disclosed.

A surgical instrument comprising a control system configured to alter and/or reduce the capability of the surgical instrument is disclosed.

A surgical instrument configured to detect its orientation and adjust its operation based on the detected orientation is disclosed.

A surgical instrument comprising a flexible circuit is disclosed.

A surgical instrument including a flex circuit comprising a sensor system.

A surgical instrument including a signal interference detection system.

A surgical instrument comprising a sensing circuit and a control system which is responsive to data from the sensing circuit.