The present invention relates to the field of laser machining and provides an optical lens, comprising a lens group and a diaphragm. The method may include providing a first intravascular device having a distal portion and at least one aperture and positioning the distal portion of the first intravascular device in the vascular wall. Such operations, for example, may represent a configurable processor ISA. The distance between the radiation source and the conveyor mechanism may be varied dependent upon changes in the dimension of individual articles relative to the dimension of other articles, in a direction substantially perpendicular to the direction of the radiation source and the path of movement of the articles on the conveyor mechanism. Subsets of the series of pseudo random bits from the BBS pseudo random number generators are combined to generate a cryptographic key. Since the reference position is automatically set and updated to compensate the abraded amount of the welding tip, the distal end of the movable welding tip is constantly positioned to a predetermined position for applying a predetermined pressure to the workpiece.