A method for separating photomask pattern, including the following steps: first, a layout pattern is provided, wherein the layout pattern is defined to have at least one critical pattern and at least one non-critical pattern. The hand-held device brings the dielectric fluid, power supply, and control system structure to the fastener in a compact tool to permit EDM machining to be brought to large structures. Each light emitting source emits a different color of light that is incident on the blazed diffraction grating. A drive mechanism moves the restriction elements from positions allowing the small cassette to be loaded to positions where the restriction elements allow the large cassette TO be loaded. The catheter can also be provided with a centering balloon or a set of centering wire loops to center the radioactive source radially within the blood vessel. This system is for preparing a mist by pulverizing and dissolving a gas and a liquid at a density of not less than a predetermined value, and contacting the mist to the skin and mucous membrane of a living organism.