A variety of techniques may be employed, alone or in combination, to enhance contact between a processed substrate and applied megasonic energy. More particularly devices and methods are directed maintaining patency of channels that alter gaseous flow within a lung to improve the expiration cycle of, for instance, an individual having chronic obstructive pulmonary disease. The lower ends of the legs extend through and beyond the flange and define an upwardly facing shoulder which catches behind the flange, on the lower side of the flange to hold the legs and the base together. The metadata management system includes a mapping means capable of mapping schemata of the source databases to dimensions and measures in the metadata based on the technical information.