Variations in spatial phase distribution due to static magnetic field changes are corrected based on phase variations at points, specifically, at three points or a plurality of points selected by ROI, in an area where no temperature change is encountered. The patterns form an information-encoding sequence of transitions of differential emissivity along a scan path over the patterns, that encodes a set of information. The modified energy function is the energy function used in image segmentation with an additional term comprising a scalar value. The stuffer box includes a stuffer box channel adjacent to the pair of doctor blades, and the stuffer box channel includes a surface consisting of a hard material having a hardness of at least 60 Rc. , by altering the pH, to trigger degradation of at least part of the device structure to enable the device structure or parts thereof to be excreted from the bladder.