A resolution optimization unit determines an optimal sound velocity corresponding to a tissue component at each position in a scan slice, and calculates a reception delay time or the like for each reception beam from each position in the scan slice. The method can include feeding a media sheet in a media sheet travel direction through the fuser nip. The size or amount of the prosthesis inserted into the interior region of the vertebral disc may be a characteristic of the disc or the prosthesis. Decoding state information is stored in another register of the processor. The electrode facing the lower side of the element is patterned so that localized electrostatic forces are generated across the viscoelastic material when a voltage is applied across both electrodes.