The surgical instrument includes a distal tool, a rigid or flexible elongated shaft that supports the distal tool, and a proximal handle or control member, where the tool and the handle are coupled to the respective distal and proximal ends of the elongated shaft via distal and proximal bendable motion members. The large-diameter tubular part is provided on its internal periphery with an outwardly divergent tilting surface while the bushing is provided with an annular projecting portion to be abuttingly disposed on the tilting surface, and laser is irradiated, penetrating through the annular projecting portion onto the tilting surface. Several exercise modules are provided, each having at least one display file, at least one script corresponding to the display file, and a work file, to be loaded into the target system. The second transistor includes a second active region comprising a second source and a second drain; and a second gate electrode over the second active region and connected to the first gate electrode, wherein the first source and the second source are electrically connected, and the first drain and the second drain are electrically connected. Related methods are also disclosed. The adjustment has a gain responsive to the wire feed speed input, such that there are at least three gains over a range of possible wire feed speeds, in one embodiment.