Disclosed is a boosting voltage control circuit. The shunt device is implanted between an artery and a vein, preferably between a peripheral artery and the inferior vena cava. A target locating means determines the angular location of the target from the phase difference signal. A front and rear support are respectively connected to a front end and rear end of the first rail. The user can utilize the device without having to distinguish between pre-cached and free memory. An example of an apparatus for analyzing light by mode interference includes a number of waveguides to support in a multimode region two modes of the light of a particular polarization and a plurality of scattering objects offset from a center of at least one of the number of waveguides.