The invention is generally related to the estimation of position and orientation of an object with respect to a local or a global coordinate system using reflected light sources. A cylindrical portion comprises a plurality of laminated composite layers concentrically assembled to one another along a longitudinal axis. A first section extends vertically between the window opening and the door opening, a second section extends vertically between the window opening and the door opening, and a third section of a width substantially equal to that of the window opening extends under the window opening. The shim and the pressure increasing plate are sandwiched between the top portions. The present device may be used in the esophagus in the area of the sphincter to treat GERD, in the female urethra to treat FSI or at the vesicouretal junction to treat VUR. The etch solutions are formulated as a mixture of hydrofluoric acid and an organic acid having a dielectric constant less than water, optionally, with an inorganic acid, and a pH of 1 or less.