Abstract: A variable spacing diffraction grating is fabricated using micro-electromechanical (MEMS) technology. An array of interconnected beam elements is fabricated into a diffraction grating and mounted in such a manner that one or both ends of the array of beam elements may be actuated using a mechanical actuator. The beam elements may be linear, spiral shaped or arranged in a staircase structure. Applying a force to one or both ends of the array of beam elements changes the spacing of the grating, and presents a different ruling spacing distribution to incoming radiation, thus altering the diffracted angle among individual diffraction orders of the wavelength. Controlling the diffracted signal in this way allows for specific diffraction pass bands to be fixed on a particular detector or a particular area of a detector or optical relay lens or lenses.

Abstract: The present invention relates to a method for an early stage detection of three specific pregnancy-related disorders: preeclampsia, intrauterine growth retardation and preterm delivery. According to the method, an antigen consisting of a specific human-derived placental soluble protein, known as PP-13, is determined by radioimmunoassay or ELISA. In the radioimmunoassay method, the PP-13 is labelled by a radioactive iodine and the bounded iodine is counted and correlated with standard curves. The best results are obtained when the protein to be labelled by radioactive iodine is present at a concentration of above 0.71 mg/ml. In case of the ELISA method, the quantitative determination of PP-13 is carried out with an alkaline phosphatase substrate and measured at an optical density of 405 nm.